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Anatomy and Physiology

by: Orlando Stark

Anatomy and Physiology BIOL 2403

Orlando Stark
University of Texas-Pan American (UTPA)
GPA 3.87

Bonnie Gunn

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This 150 page Class Notes was uploaded by Orlando Stark on Thursday October 29, 2015. The Class Notes belongs to BIOL 2403 at University of Texas-Pan American (UTPA) taught by Bonnie Gunn in Fall. Since its upload, it has received 10 views. For similar materials see /class/231307/biol-2403-university-of-texas-pan-american--utpa- in Biology at University of Texas-Pan American (UTPA).

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Date Created: 10/29/15
Chapter 4 THE TISSUE LEVEL OF ORGANIZATION Chapter 4 Anatomy and Physiology Lecture Chapter 4 2 THE TISSUE LEVEL OF ORGANIZATION TISSUES AND HISTOLOGY Tissues Are collections of similar cells and the substances surrounding them Four Primary Types of Tissues 1 Epithelial tissue 2 Connective tissue 3 Muscle tissue 4 Nenous tissue Histology Is the microscopic study of tissue Pathologist Is a physician who specializes in laboratory studies of cells and tissues Biopsy Is the process of removing tissue samples from patients surgically orwith a needle for diagnostic purposes Autopsy Is an examination of the organs of a dead body to determine the cause of death or to study the changes caused by a disease Types of Tissues and Their Origins Body tissue can be classified into four principal types according to their function and structure 1 Epithelial tissue which covers body surfaces lines hollow organs body cavities and ducts and forms glands 2 Connective tissue which protects and supports the body and its organs binds organs together stores energy reserves as fat and provides immunity Chapter4 3 3 Muscle tissue which is responsible for movement and generation of force 4 Nervous tissue which initiates and transmits action potential nerve impulses that help coordinate body activities About 8 days after fertilization the mass of cells that results from several cell divisions embeds in the lining ofthe uterus and begins to form Primary Germ Layers EPITHELIAL TISSUE Two subt es ofE ithelial Tissue E ithelium Covering and Lining Epithelium Glandular Epithelium Forms the outer covering of external body surfaces and the outer covering of some internal organs Lines body cavities and the interior of the respiratory and gastrointestinal tracts blood vessels and ducts Makes up along with nervous tissue the parts ofthe sense organs for smell hearing vision and touch which respond to stimuli Is the tissue from which gametes sperm and eggs develop General Features of Epithelial Tissue Note Ten general features of epithelial tissue Covering and Lining Epithelium By layers and by shape Chapter 4 A Arrangement of Layers Simple Epithelium fthe cells of the tissue are arranged in a single layer fthe epithelium is specialized for absorption or filtration fthe epithelium is in an area that has minimal wear and tear Stratified Epithelium fthe cells of the tissue are stacked in several layers fthe epithelium is found in an area with a high degree of wear and tear Pseudostratified Epithelium Has only one layer of cell but appear to have several Some ofthe cells do not reach the surface an arrangement that gives the tissue a multi layered or stratified appearance The cells in Pseudostratified epithelium that do reach the surface either secrete mucus or contain cilia that move mucus and foreign particles for eventual elimination from the body B Cell Shapes 1 Sguamous Cells are flattened and scalelike Are attached to each other and form a mosaic pattern 2 Cuboidal Cells are usually cubeshaped in cross section Sometimes appear as hexagons Chapter 4 5 3 Columnar Cells are tall and cylindrical or somewhat rectangular Appearing as somewhat rectangular in shape when set on end 4 Transitional Cells often have a combination of shapes Are found where there is a great degree of distention or expansion in the body Transitional cells in the basal bottom layer of an epithelial tissue may range in shape from cuboidal to columnar In the intermediate layer they may be cuboidal or polyhedral having many sides In the superficial layer they may range from cuboidal to sguamous depending on how much they are pulled out of shape during certain body functions D Classification Considering layers and cell shapes in combination covering and lining epithelium may be classified as follows a Sim le 1 Squamous 2 Cuboidal 3 Columnar b Stratified 1 Squamous 2 Cuboidal 3 Columnar 4 Transitional c Pseudostratified Columnar Chapter 4 6 A SIMPLE EPITHELIUM 1 Simple Sguamous Epithelium Description Single layer of M scalelike cells ts surface resembles a tiled floor Centrally located nuclei Location Lines air sacs of lungs glomerular Bowman39s capsule of kidneys and inner surface of the membranes labyrinth and tympanic membranes of ear Called Endothelium when it lines heart blood and lymphatic vessels and forms capillaries Called Mesothelium when it lines the ventral body cavity and covers viscera as part of a serous membrane Function filtration absorption exchange and secretion in serous membranes osmosis and diffusion 2 Simple Cuboidal Epithelium Description Single layer of cubeshaped cells Centrally located nuclei Location Covers surface of ovary lines anterior surface of capsule ofthe lens of eyes forms pigmented epithelium of retina of eye and lines kidney tubules and smaller ducts of many glands Function Secretion and absorption 3a Simple Columnar Epithelium nonciliated Description Single layer of nonciliated rectangular cells Contains goblet cells in some locations Nuclei at bases of cells Chapter4 7 Location Lines the gastrointestinal tract from the cardia of the stomach to the anus excretory ducts of many glands and gallbladder Function Secretion and absorption 3b Simple Columnar Epithelium Ciliated Description Single layer of ciliated columnar cells Contains goblet cells in some locations Nuclei at base of cells Location Lines a few portions of upper respiratory tract uterine fallopian tubes uterus some paranasal sinuses and central canal of spinal cord Function Moves mucus by ciliary action B STRATIFIED EPITHELIUM 1 Stratified Sguamous Epithelium Exists in two forms 1 Keratinized stratified squamous epithelium and 2 nonkeratinized stratified squamous epithelium Description Several layers of cells Cuboidal to columnar shape in deep layers Squamous cells in superficial layers Basal cells replace surface cells as they are lost Location Nonkeratinized variety lines wet surfaces such as lining of the mouth tongue esophagus part of epiglottis and vagina Keratinized variety form outer layer of skin tough layers Function Protection Keratin is a protein that is waterproof and resistant to friction and helps repel bacteria A fibrous protein of high sulfur content present in epidermal structure as horn nails claws and feathers Nonkeratinized found on areas subject to wear and tear Chapter4 8 2 Stratified Cuboidal Epithelium Description Two or more layers of cells in which the surface cells are cubeshaped Location Ducts of adult sweat glands fornix of conjunctiva of eye cavernous urethra of male urogenital system pharynx and epiglottis Function Protection against infection absorption and secretion 3 Stratified Columnar Epithelium Description Several layers of polyhedral having many sides or surfaces cells Columnar cells only in superficial layer Location Lines part of male urethra large excretory ducts of some glands and small areas in anal mucus membrane Function Protection and secretion 4 Transitional Epithelium Description Resembles Nonkeratinized stratified squamous tissue except that superficial cells are larger and have a rounded free surface Location Lines urinary bladder and portions of ureters and urethra stretching Function Permits distention inflation or expansion stretching C Pseudostratified Columnar Description not a true stratified tissue Nuclei of cells at different levels All cells attached at basement membrane but not all reach surface Has only one layer but gives the appearance of many Location lines large excretory ducts of many large glands epididymis male urethra and auditory Eustachian tubes Ciliated variety with goblet cells lines most ofthe upper respiratory tract and some ducts of male reproductive system Function Secretion and movement of mucus and sperm cells by ciliary action Chapter 4 9 Glandular Epithelium A Gland may consist of one cell or a group of highly specialized epithelial cells that secrete substances into ducts onto a surface or into the blood Two types ofglands 1 Exocrine Gland Description Secretes products into ducts Location Sweat oil wax and mammary glands of the skin Digestive glands such as salivary glands that secrete into mouth cavity and pancreas that secrete into the small intestine Function Produces mucus perspiration oil wax milk or digestive enzymes 2 Endocrine Gland Description Secretes hormones into blood Location Pituitary at base of brain Thyroid and parathyroid near larynx Adrenals suprarenal above kidneys Ovaries in pelvic cavity Testes in scrotum Pineal at base of brain and Thymus in the thoracic cavity Function Produces hormones that regulate various body activities Functional Characteristics of Epithelial Tissues Most epithelial cells some muscle cells and some nerve cells are tightly joined to form a close functional unit Cell Junctions the points of contact between adjacent plasma membranes Chapter 4 10 Three Types of Cell Junctions Serve Distinct Functions 1 Tight Junctions form fluid tight seals between cells like the seal on a Ziploc sandwich bag Common among epithelial cells that line the stomach intestine urinary bladder 2 Anchoring Junctions fasten cells to one another or to the extracellular material Common in tissues subjected to friction and stretching skin heart uterus 3 Communicating Junctions permit electrical or chemical signals to pass from cell to cell Gag Junction are microscopic structure that functions as communicating junction Connexon are proteins spanning the gap that form minute fluid filled tunnels Anchoring Junctions include a Adherent Junction connect to microfilaments ofthe cytoskeleton and links cells to another or anchor cells to extracellular materials b Desmosomes form firm attachments between cells somewhat like spot welds c Hemidesmosomes look like half a desmosome they anchor the basal bottom epithelial cell plasma membrane to extracellular materials at the junction between epithelial and connective tissues CONNECTIVE TISSUE Connective Tissue is the most abundant and most widely distributed tissue in the body Chapter 4 11 General functions 1 Binds together supports and strengthens other body tissues 2 Protects and insulates internal organs 3 Compartmentalizes structures such as skeletal muscles Blood is a fluid connective tissue a majortransport system within the body Adipose fat Tissue also a connective tissue is the major site of stored energy reserves General Features of Connective Tissue 1 Consists ofthree basic elements a Cell b Ground substance c Fibers Matrix is the combination of ground substance and fiber Separeates connective tissue cells as they rarely touch one another 2 Do not occur on free surfaces such as the surface of a body cavity or the external surface ofthe body in contrast to epithelial However joint cavities are lined by a type of connective tissue called areolar connective tissue 3 Like epithelium has a nerve supply except for cartilage 4 Is usually highly vascular has a rich blood supply unlike epithelium Chapter4 12 5 Its matrix which may be fluid semifluid glatinous fibrous or calcified is usually secreted by the connective tissue cells and adjacent cells and determines the tissues qualities Connective Tissue Cells The cells are derived from mesodermal embryonic cells called mesenchymal cells Each major type of connective tissue contains an immature class of cell whosename ends in bast This cell retains its capacity for division and secretes the matrix ground substance and fibers that is characteristic ofthe tissue Classification of Connective Tissues l Embryonic Connective Tissue A Mesenchyme B Mucous Connective Tissue ll Mature Connective Tissue A Loose Connective Tissue 1 Areolar connective tissue 2 Adipose tissue 3 Reticular connective tissue B Dense Connective Tissue 1 Dense regulator connective tissue 2 Dense irregular connective tissue 3 Elastic connective tissue C Cartilage 1 Hyaline cartilage 2 Fibrocartilage 3 Elastic cartilage Chapter 4 13 D Bone Osseous Tissue E Blood vascular Tissue Embryonic Connective Tissue Primarily in the Embryo or Fetus A Mesenchyme Description Consists of highly branched mesenchymal cells embedded in a fluid substance Location Under skin and along developing bones of embryo Some mesenchymal cells found in adult connective tissue especially along blood vessels Function Form all other kinds of connective tissue B Mucous Connective Tissue Description Consists of flattened or spindleshaped cells embedded in a mucus like substance containing fine collagenous fibers Location Umbilical cord of fetus Function Support Mature Connective Tissue Mature Connective Tissue is connective tissue that differentiates from mesenchyme and exists in the newborn and does not change after birth It is subdivided into several kinds Connective tissue groper cartilage bone tissue and vasculartissue A Connective Tissue Proper Has a more or less fluid intercellular material and a typical cell is the fibroblast Five examples exist Chapter 4 14 1 Loose lareolarl Connective Tissue Description Consists of fibers Collagenous elastic and reticular and several kinds of cells fibroblasts macroophages plasma cells adipocytes and mast cells embedded in a semifluid ground substance Location Subcutaneous layer of skin mucous membranes blood vessels nerves and body organs Functions Strength elasticity and support 2 Adipose Tissue Description Consists of adipocytes quotsignet ringshapedquot cells with peripheral nuclei that are specialized for fat storage Location Subcutaneous layer of skin around heart and kidneys marrow of long bones and padding around joints Function Reduces heat loss through skin Serves as an energy reserve Supports and protects 3 Dense Collagenousl Connective Tissue Description Consists of predominantly collagenous fibers arranged in bundles Location Forms tendons ligaments aponeuroses a flat sheetlike tendon attaches muscles to bone membranes around various organs and fasciae Function Provides strong attachment between various structures Dense Regular Connective Tissue Bundles of collagen fibers have an orderly parallel arrangement Withstands pulling in one direction Appear in rows between the fibers Dense Irregular Connective Tissue Bundles of collagen fibers interwoven without regular orientation Chapter 4 15 B Found in parts of the body where tensions are exerted in various directions Heart valves and the perichondrium a membrane around cartilage are examples 4 Elastic Connective Tissue Description Consists of predominantly freely branching elastic fibers Fibroblasts present in spaces between fibers Location Lung tissue wall of arteries trachea bronchial tubes true vocal cords and ligaments flava of vertebrae Function Allow stretching of various organs 5 Reticular Connective Tissue Description Consists of a network of interlacing reticular fibers with thin flat cells wrapped around fibers Location Liver spleen lymph nodes and basal lamina underlying epithelia Function Forms stroma of organs Binds together smooth muscle tissue cells Cartilage Capable of endiving considerably move stress than tissues Unlike other connective tissues cartilage has no blood vessels or nenes except for those in the perichondrium membranes covering Three kinds of cartilage are recognized 1 Hyaline Cartilage Description Also called Gristle Appears as a bluish white glossy mass Contains numerous chondrocytes cells of mature cartilage Is the most abundant type of cartilage Chapter4 16 Location Ends of long bones ends of ribs parts of larynx trachea bronchi bronchial tubes and embryonic skeleton Function Provides movement atjoints flexibility and support 2 Fibrocartilage Description Consists of chondrocytes scattered among bundles of collagenous fibers Location Symphysis pubis intenertebral discs and menisci of knee Function Support and fusion 3 Elastic Cartilage Description Consists of chondrocytes located in a threadlike network of elastic fibers Location Epiglottis of larynx external ear and auditory Eustachian tubes Function Gives support and maintains shape Growth of Cartilage The growth of cartilage follows two basic patterns a Interstitial endogenous growth The cartilage increases rapidly in size through the division of existing chondrocytes and continuous deposition of increasing amounts of intercellular matrix by the chondrocytes The formation of new chondrocytes and their production of new intercellular matrix causes the cartilage to expand from within thus the term interstitial growth This growth pattern occurs while the cartilage is young and pliable during childhood and adolescence b Appositional exogenous Growth The growth of cartilage occurs Chapter4 17 because of the activity of the inner chondrogenic layer of the perichondrium The matrix is deposited on the surface ofthe cartilage increasing its size Appositional growth starts later than interstitial growth and continues throughout life c Osseous Tissue Bone Cartilage 39oints and Osseous Tissue bone comprise the skeletal syste Osteocytes are mature bone cells Function Support soft tissues Protects delicate structures Works with skeletal muscles to facilitate movement Stores calcium and phosphorus Houses red marrow which produces several kinds of blood cells and Houses yellow marrow which contains lipids as an energy source d Vascular Tissue Blood Vascular tissue blood is a liquid connective tissue that consists of an intercellular substance called plasma and formed elements cells and celllike structures 1 Plasma is a strawcolored liquid that consists mostly of water plus some dissolved substances nutrients enzymes hormones respiratory gases and ions 2 Formed elements are erythrocytes red blood cells leucocytes white blood cells and thrombocytes platelets Chapter4 18 Erythrocytes red blood cells function in transporting oxygen to body cells and removing carbon dioxide from them Leucocytes white blood cells are involved in phagocytosis immunity and allergic reactions Thrombocytes platelets function in blood clotting MEMBRANES Epithelial Membrane is the combination of an epithelial layer and an underlying connective tissue layer Example Mucous membranes Serous membranes Cutaneous membranes orskin and Synovial membrane does not contain epithelium 1 Mucous Membrane or Mucosa lines a body cavity that opens directly to the exterior Lines the entire gastrointestinal respiratory excretory and reproductive tracts Secretes mucus which prevents the cavities from drying out 2 Serous Membranes or Serosa Lines a body cavity that does not open directly to the exterior and it covers the organs that lie within the cavity a Parietal Portion part of serous membrane attached to the cavity wall b Visceral Portion part that covers and attaches to the organs inside these cavities Pleura the serous membrane lining the thoracic cavity and covering the lungs Chapter4 19 Pericardium the membrane lining the heart cavity and covering the heart Peritoneum the serous membrane lining the abdominal cavity and covering the abdominal organs and some pelvic organs Serous Fluid fluid secreted by serous membrane that allows the organs to glide easily against one another or against the walls of the cavities 3 Cutaneous membrane or skin constitutes an organ of the integumentary system 4 Synovial Membranes lines the cavities ofthe freely movable joints Like serous membranes they line structures that do not open to the exterior Unlike mucous serous and cutaneous membranes they do not contain epithelium and are therefore not epithelial membranes Synovial Fluid fluid secreted by synovial which lubricates the articular cartilage at the ends of bones as they move atjoints and nourished the articular cartilage covering the bones that form the joints MUSCLE TISSUE Muscle Tissue is modified for contraction and thus provides motion maintenance of posture and heat production Consists of fibers cells that are highly specialized 1 Skeletal Muscle Tissue is attached to bones Are Striated that is the fibers cells contain alternating light and dark bands striations that are perpendicular to the long axes of the Chapter4 20 bones Are voluntary that is it can be made to contract or relax by conscious control Description Cylindrical striated fibers with several peripheral nuclei Are voluntary Location Usually attached to bones Function Motion posture heat production 2 Cardiac Muscle Tissue Description Quadrangular branching striated fibers with one centrally located nucleus Contains intercolated discs Usually involuntary Location Heart wall Function Motion contraction of heart 3 Smooth Muscle Tissue Description Spindleshaped nonstriated fibers with one centrally located nucleus Usually involuntary Location Walls of hollow internal structures such as blood vessels stomach intestines and urinary bladder Function Motion constriction of blood vessels propulsion of foods through gastrointestinal tract contraction of gallbladder NERVOUS TISSUE Two principal kinds a Neurons or nerve cells b Neuroglia are cells that protect and support neurons Description Neurons nerve cells consist of a cell body and processes extending from the cell body called dendrites usually conduct impulses toward cell body or axons usually conduct Chapter 4 21 impulses away from cell body Location Nervous system Function Exhibits sensitivity to various types of stimuli converts stimuli to nerve impulses and conducts nene impulses to other neurons muscle fibers orglands TISSUE REPAIR AN ATTEMPT TO RESTORE HOMEOSTASIS Tissue Repair is the replacement of damaged or destroyed cells by healthy ones It begins during the active phase of inflammation and is not completed until after harmful substances in the inflamed area have been neutralized or removed Repair Process 1 lfthe injury is superficial slight tissue repair involves pus removal if pus is present scab formation and parenchymal regeneration lf damage is extensive granulation tissue is involved ie involves rapid cell division Conditions Affecting Repair 1 Nutrition is important to tissue repair a Vitamin A is essential in the replacement of epithelial tissues especially in the respiratory tract b Vitamins B thiamine nicotinic acid riboflavin are coenzymes needed by many enzymes systems in cells Are needed for enzymes involved in decomposing glucose to 002 and H20 which is crucial to both heart and nervous tissue c Vitamin C directly affects the normal production and maintenance of intercellular substances It is required for the manufacture of cementing elements of Chapter 2 1 THE CHEMICAL LEVEL OF ORGANIZATION CHAPTER 2 Anatomy and Physiology Lecture Chapter2 2 THE CHEMICAL LEVEL OF ORGANIZATION 1 Human body is composed of chemicals and all body activities are chemical in nature 2 Most food we eat and drink are chemical substances that function in our bodies to keep us alive 3 To understand our body chemical make up we need to know which chemical elements are present in the body human organism and how they interact BASIC CHEMISTRY 1 The structure and function of your body result from thousands of interactions that take place at the chemical level of organization 2 All life processes involve chemical reactions eg calcium participates in muscle contraction for movements sodium and potassium are necessary for nene impulses related to responsiveness 3 To understand the nature of the matter that composes your body and the changes it undergoes in health and in disease you will need to know how it is organized and how different elements of matter interact with one another MATTER AND ENERGY All living and nonliving things consist of matter 1 Matter is anything that occupies space and has mass Chapter2 3 Three States of Matter 1 Solid 2Lhuw 3 Gas Although the terms mass and weight often are used interchangeably there is a distinction Mass is the amount of matter that a substance contains Weight is the gravitational force acting on an object of a given mass Although your mass is the same your weight depends on where you are In outer space weight is close to zero but mass remains the same as it was on earth at sea level 2 Energy is the capacity to do work that is to put mass into motion Mass and energy can be neither created nor destroyed but one can be converted into the other Two Principal Kinds of Energy a Potential Energy inactive or stored energy b Kinetic Energy energy of motion Ener Potential or Kinetic exists in several different forms i Chemical Energy is the energy released or absorbed in the breaking apart or forming of chemicals ii Radiant Energy such as heat and light is energy that travels in waves iii Electrical Energy results from the flow of electrons or other charged Chapter2 4 particles such as ions Action potentials impulses in nerve and muscle cells are examples of electrical energy Chemical Elements All forms of Matter are made up of a limited number of building blocks called chemical elements Chemical elements are substances that cannot be split into simpler substances by ordinary chemical reactions 109 different elements are recognized by scientists 92 ofthem occur in nature Elements are given letter abbreviations usually derived from the first or first and second letters ofthe English or Latin name for the element called Chemical Symbols eg H Hydrogen C Carbon 0 Oxygen N Nitrogen Ca Calcium Na Natrium Sodium K Kalium Potassium Fe Ferrum lron P Phosphorus 26 ofthe 92 naturally occurring elements are present in your body The following make up about 96 of the body39s mass oxygen carbon Chapter 2 5 hydrogen nitrogen The following make up about 39 of the body39s mass calcium phosphorus potassium sulfur sodium chlorine magnesium iodine iron Trace element make up about 01 of the body39s mass because they are present in minute concentrations Structure of Atoms Each element is made up of units of matter called atoms An element is a quantity of matter composed of atoms all of the same type A handful ofthe element carbon such as pure coal contains only carbon atoms A tank of oxygen contains only oxygen atoms Atoms the smallest units of matter that enter into chemical reactions An Atom consists of three ma39or types of subatomic particles a Electrons e negatively charged b Protons p positively charged Within the Nucleus c Neutrons n2 uncharged neutral Chapter2 6 The number of electrons in an atom of an element always equals the number of protons gt p e Atom is electrically neutral its total charge is zero since each electron carries one negative charge the negatively charged electrons and the positively charged protons balance each other Dalton or Atomic Mass Unit lamul is the standard unit for measuring the mass of atoms and their subatomic particles Neutron has a mass of 1008 daltons Proton has a mass of 1007 daltons Electron has a mass of 00005 daltons Atomic Mass Atomic Weigh adding up the masses of all the protons neutrons and electrons in an atom Number of Protons in the nucleus makes the atoms of one element different from those of another Each different kind of atom has a different number of protons in its nucleus Atomic Number the number of protons in an atom Therefore each kind of atom or element has a different atomic number eg oxygen has 8 atomic numbers because its nucleus has 8 protons while sodium has 11 Mass number is the total number of Protons and Neutrons For sodium Na with 12 neutrons the mass number is 23 11 protons 12 neutrons 23 Since electron has so little mass the Atomic Mass of an atom may be nearly equal to its mass number Chapter2 7 Atoms of one electron however although chemically alike may have different mass number because they have different number of neutrons Isotopes Different atoms of an element that have the same number of protons atomic number but different number of neutron thereby having different Mass number All isotopes of an element have the same chemical properties because they have the same number of electrons Eg Isotopes of oxygen are 160 170 and 180 or 016 017 and 018 The numbers indicate the mass number total number of Protons and Neutrons in each Isotope Radioactive Isotopes Radioisotopesl Are unstable isotopes their nuclear structure decays or changes to a more stable configuration In decaying they emit radiation alpha or beta particular or gamma rays Halflife is the time required forthe radioactive isotope to emit half of the original amount of radiation Electrons and Chemical Reactions Chemical reaction occurs when atoms combine with or break apart from other atoms In the process new products with different chemical properties are formed Electron interactions are the basis of all chemical reaction Electron in their motion around the nucleus tend to spend most ofthe time in specific atomic regions which are represented as circles lying at varying distances from the nucleus Electron shell is represented by each circle which can hold a certain maximum of electrons Chapter2 8 a First Shell the electron shell nearest the nucleus and never holds more than two electrons no matter the element b Second Shell holds maximum of eight electrons c Third Shell holds up to E electrons Atoms whose atomic number is less than 20 can hold a maximum of electrons which more complex atoms can hold a maximum of electrons on 3rd shell d Higher Shells there are as many as seven can contain many more electrons eg lodine the largest element present in the human body holds electrons in the fourth shell and Z in the fifth An atom tends to either empty their outermost shell of fill it to the maximum To do so atom may give up accept or share electrons with other atoms whichever is easiest Valence combining capacity is the number of extra or deficient electrons in the valence shell the outmost shell Chlorine Cl Atomic Number 17 Mass Number 35 or 37 Atomic Mass 35453 Has Z electrons on the outermost will be easier to pick up 1 electron Sodium Na Atomic Number 11 Mass Number 22 or 23 Atomic Mass 22990 Has 1 electron on the outermost will be easier to give up than pick up more Z electrons Chapter2 9 Helium He Atomic Number 2 Mass Number 3 or 4 Atomic Mass 4003 Outermost electron shell is completely filled do not need to gain or lose electron Are called Inert elements Inert Elements are not chemically active and do not usually participate in chemical reactions Eg Helium Argon and Neon Atoms with incompletely filled outer shells such as Na and Cl tend to combine with each other in chemical reactions Molecule results when two or more atoms combine in a chemical reaction For example Can be same atoms H H gt H2 Can be different atoms H Cl gt HCI Compound is a substance that can be broken down into two or more different elements by chemical means The molecules of a compound always contain atoms of two or more different elements Electrons and Chemical Bonding Outermost electrons of an atom determine its chemical behavior Chemical Bonding occurs when the outermost electrons are transferred or shared between atoms Different Kinds of Chemical Bonds a lonic Bonds b Covalent Bonds Chapter2 10 A Ions and Ionic Bonds Atoms are electrically neutral because the number of positively charged protons equals the number of negatively charged electrons When an atom gains or loses electrons however this balance is upset Cations If the atom loses electrons it acquires a positive charge Anions lfthe atom gains electrons it acquires a negative charge lon is a negatively or positively charged particle B Covalent Bonding Covalent Bonding When atoms share one or more pairs of electrons resulting to a molecule Single covalent bond When an electron pair is shared between two atoms Double covalent bond When two atoms share four electrons two from each atom Nonpolar covalent bods When electrons are shared equally between atoms as in a hydrogen molecule Bonds between two identical atoms always are nonpolar covalent bonds Single covalent bond between carbon and hydrogen is another example of a nonpolar covalent bond Polar covalent bonds When electrons are not equally shared between atoms as in oxygen and hydrogen Bond between oxygen and hydrogen in a molecule of water is the most important example in living systems Chapter 2 11 Partial negative charge indicates that atom that attracts electrons more strongly Partial positive charge indicates the atom that does not attract electrons strongly Polar covalent bonds allow water to dissolve many molecules that are important to life Intermolecular Forces Intermolecular forces result from the weak electrostatic attraction between the oppositely charged parts of molecules or between ions and molecules Hydrogen Bonds Provides temporary bonding between certain atoms within large complex molecules such as proteins and nucleic acids Hydrogen bond consists of a hydrogen atom covalently bonded to one oxygen atom or nitrogen atom but attracted to another oxygen or nitrogen atom Because hydrogen bonds are weak only about 5 as strong as covalent bonds they do not bind atoms into molecules However they do serve as bridges between different molecules or between various parts of the same molecule Example Between water molecules Between various parts of the same molecules Chapter2 12 Chemical Reactions and Energy Chemical Reactions involve the making or breaking of bonds between atoms After a chemical reaction the total number of atoms remain the same but because they are rearranged they are new molecules with new properties Metabolism refers to all chemical reaction occurring in an organism Several factors that determine whether a collision will occur and cause a chemical reaction bongo x Concentration Speed Energy Proper orientation Synthesis Reactions Anabolism Synthesis reaction when two or more atoms ions or molecules combine to form new and larger molecules Synthesis means quotto put togetherquot and synthesis reactions involve the forming of new bonds Synthesis reaction can be expressed in the following way A B Combine to form AB Atom ion Atom ion New molecule AB U U Reactants Product Example N2 3H2 2NH3 All the synthesis reactions that occur in your body are collectively Chapter2 13 called anabolic reactions or simply anabolism Eg Combining Amino Acids to form proteins Combining glucose molecules to form glycogen B Decomposition Reaction Catabolism To decompose means to break down into smaller parts In a decomposition reaction bonds are broken Large molecules are broken down into smaller molecules ions or atoms A decomposition reaction occurs in this way AB Breaks down into A B Molecule AB Atom ion or Molecule A Atom ion or molecule B Example CH4 C 2H2 One methane molecule one carbon atom two hydrogen molecules All the decomposition reactions that occur in y our body are collectively called catabolic reactions or simply catabolism Eg Digestion of food molecules C Exchange Reactions Are partly synthesis and partly decomposition AB CD 6 AD BC Bonds between A and B and between C and D break in a decomposition process New bonds then form between A and D and Chapter2 14 between B and C in asynthesis process D Reversible Reactions The product can revert to the original reactants A reversible reaction is indicated by two arrows Combines to form A B 2 AB Breaks down into Some reactions are reversible only under special conditions Heat is applied A B 2 AB Water is added Inorganic Chemistry Usually lack carbon Usually small in living systems Are ionically bonded molecules Examples Water oxygen carbon dioxide many salts acids and bases a Water Most abundant inorganic substance in living systems 60 of Red blood cells 75 of Muscle tissue 92 of Blood plasma liquid portion of blood Chapter 2 Functions 1 An excellent solvent and suspending medium Solvent Solute Solution Termed a quotuniversal solventquot since it serves as a solvent for many solutes 2 Participate in chemical reactions 3 Absorbs and releases heat very slowly 4 Requires a large amount of heat to change from a liquid to a gas 5 Serves as a lubricant in several regions of the body Inorganic Acids Bases and Salts When molecules of inorganic acids bases or salts dissolve in water they undergo ionization or dissociation that is they separate into ions Paiticles formed during ionization are called Electrolytes because the solution will conduct an electric current An Acid a substance that when dissolved in water dissociated into one or more hydrogen ions Hl and one or more anions negative ions H HCL in water Cl Acids are Proton donors A Base a substance that when dissolved in water dissociates into one or more hydroxide ions OHl and one or more cations positive ions K KOH inwater OH Chapter2 16 Bases are Proton acceptors iii A Salt a substance that when dissolve din water dissociates into cations and anions neither of which is H or OH K KCI in water Cl Acids and Bases react with one another to form Salts HCI KOH KCI H20 Acid Base Salt Water AcidBase Balance The Concept of 9H Body fluids must maintain a fairly constant balance of acids and bases pH is used to describe the degree of Acidity or Alkalinity basicity of a solution Exhibit 22 pg 40 Increasing Acidity 7 ONeutrality pHScale0123456789101112 13 14 8lncreasing Alkalinity basicity Organic Chemistry Usually have carbon Usually have hydrogengt Most frequently found elements Usually have oxygen Usually have nitrogen gtltgtltgtltgtlt Chapter 2 17 X X X Usually have sulfur gt Less frequently found Usually have Phosphorus Are Covalently bounded molecules Examples Carbohydrates lipids proteins nucleic acids and adenosine triphosphate ATP Carbohydrates Composed of carbon hydrogen and oxygen Have 21 ration of hydrogen to oxygen Also known as sugars and starches Provide most of the energy needed for life Can be divided into three major groups on the bases of size Monosaccharides simple sugars are compound containing from three to seven carbon atoms eg Ribose CSH lOOS glucose 06H1206 Fructose 06H126etc Disaccharides are also sugars and consist of two monosaccharides joined chemically 06H126 06H1206 gt 012H22011 H20 Glucose Fructose Sucrose Water Monosaccharide Monosaccharide Disaccharide Dehydration Synthesis is a process of disaccharide formation combination of two monosaccharides in which water is lost Digestion hydrolysis is a process by breaking down disaccharides into smaller molecules by adding water Polysaccharide consist of several monosaccharides joined together through dehydration synthesis Chapter 2 18 Have the formula 06H1005n Can be broken down into their constituent sugars through hydrolysis reactions Usually not soluble in water Usually lack characteristic sweetness of sugar like fructose monosaccharides or sucrose disaccharides Example Glycogen animal starch B Lipids Like carbohydrates are composed of carbon hydrogen and oxygen Unlike carbohydrates do not have a 21 ration of hydrogen to oxygen Most lipids are hydrophobic are insoluble in polar solvents such as water Nonpolar solvents such as chloroform and Ether readily dissolve lipids Examples Triglycerides neutral fats Phospholigids lipids that contain phosphorous Steroids cholesterol cortisol vit D Sex hormones Carotenes the yelloworange pigments in carrots Vitamins A E and 5 and Eicosanoids For efficient transport in blood m combine with proteins to form watersoluble lipoprotein 1 Triglycerides neutral fats Are the most plentiful lip in your body and in your diet At room temperature may be either solids fats or liquids oils Are the body39s most highly concentrated source of chemical energy Provide more than twice as much energy per gram as either carbohydrates or proteins Our capacity to store triglycerides in fat adipose cells is unlimited Excess carbohydrates proteins or fats are converted to triglycerides and stored in adipose fat tissue Chapter2 19 A triglyceride consist of two types of building blocks Glycerol and Fatty acids a Saturated Fats are triglycerides that contain only single covalent bonds between fatty acid carbon atoms Each carbon bonds to the maximum number of hydrogen atoms thus each fatty acid is saturated with hydrogen atoms Tend to be m at room temperature Occur mostly in animal tissues and few plant products cocoa butter palm oil and coconut oil b Monosaturated Fats contain fatty acids with one double covalent bond between two carbon atoms Are not completely saturated with hydrogen atoms Olive oil and peanut oil c Polyunsaturated fats contain more than one double covalent bond between fatty acid carbons Corn oil safflower oil sunflower oil cottonseed oil and soybean oil C Proteins Types of protein Structural Regulatory Contractile Immunological Transport Catalytic Amino Acids and Polypeptides Chemically proteins always contain carbon hydrogen oxygen and nitrogen Many contain sulfur Amino Acids are the building blocks of protein just as monosaccharides Chapter 2 20 are for polysaccharide There are 20 different amino acid each has three important groups attached to a central carbon atom 1 an amino group NH2 2 a carboxyl acid group COOH 3 a side chain R group At the normal pH of body fluid both the amino group and carboxyl group are ionized The distinctive side chain gives each amino acid its individual identity Synthesis of Protein involves in stepwise fashion One amino acid isjoined to a second a third is then added to the first two etc Peptide bond is the covalent bond between each pair of amino acids Forms between the carboxyl group COOH of one amino acid and the amino group NH2 of another A molecule of water a dehydration synthesis reaction is removed during formation of a peptide bond hydrolysis is addition of water which breaks peptide bonds a Dipeptide when two amino acids combine b Tripeptide when three amino acids combine c Polypeptide further additions of amino acids may contain from 10 to more than 2000 amino acids Using only amino acids to produce different proteins is similar to using alphabets to write millions of books and publications Think about it Level of Structural Organization Proteins exhibit four levels of structural organization 1 Primary structure is the unique sequence of amino acids making up a Chapter2 21 polypeptide strand It is genetically determined 2 Secondary structure of a protein is the repeated twisting or folding of neighboring amino acids in the polypeptide chain 3 Tertiary structure refers to the threedimensional of a polypeptide chain 4 Quaternary structure describes the arrangement ofthe individual polypeptide chains and how they bond to each other Denaturation if a protein encounters a hostile environment in which temperature pH or electrolyte concentration is altered it may unravel and lose its characteristic shape secondary tertiary and quaternary structure Denatured proteins are no longer functional A common example of denaturation is seen in frying an egg In a raw egg the egg white protein albumin is soluble and appears as a clear viscous fluid when heat is applied to the egg however the protein changes shape becomes insoluble and looks white Enzymes Normal body temperature and pressure are too low for chemical reactions to occur at a rate rapid enough to maintain life Although raising the temperature pressure and the number of reacting particles can increase the frequency of collisions and also increase the rate of chemical reactions such changes and denature proteins and damage or kill cells Enzymes are the living cell39s solution to this problem They speed up chemical reactions by increasing the frequency of collisions lowering the activation energy and properly orienting the colliding molecules In living cells enzymes function as catalysts Chapter 2 22 Catalysts substances that can speed up chemical reactions by increasing the frequency of collisions or by lowering the activation energy without themselves being altered Apoenzyme protein portion of enzyme Together apoenzyme and cofactor form a Holoenzyme or whole enzyme Cofactor Coenzyme nonprotein portion Nucleic Acids Deoxyribonucleic acid and ribonucleic acid Nucleic Acid are huge organic molecules that contain carbon hydrogen oxygen nitrogen and phosphorus Two Varieties of nucleic acid 1 Deoxyribonucleic acid DNA forms the genetic code inside each cell Each gene is a segment of a DNA molecule 2 Ribonucleic acid RNA relays instructions from the genes to guide each cell39s assembly of amino acids into proteins The basic units of nucleic acids are nucleotides A molecule of DNA is a chain composed of repeating nucleotide units Each nucleotide consists ifthree building blocks 1 A base Nitrogenous base four nitrogencontaining structure containing atoms of CH O and N called bases or nitrogen bases are present in M Adenine A Thymine T Cytosine C and Guanine G M Adenine A Uracil U Cytosine C and GuanineG Nucleotides are named according to the base that is present eg nucleotide containing thymine is thymine nucleotide Chapter 2 23 2 A Pentose Suga a five carbon sugar called deoxyribose attached to each base of DNA 3 A Phosphate Group alternating phosphate PO43 and pentose groups PO43 and pentose from the backbone of a DNA strand while bases protrude from the backbone chain Adenosine Triphosphate Adenosine Triphosphate ATPl is a molecule that is indispensable to the life of the cell It is found universally in living systems and has the essential function of providing energy for various cellular activities It is the quotenergy currencyquot of living systems Consists ofthree phosphate groups attached to an adenosine unit composed of adenine and the fivecarbon sugar ribose Removal ofthe terminal phosphate group leaves a molecule called Adenosine diphosphate ADP ATP gt ADP p E Adenosine Triphosphate Adenosine diphosphate Phosphate group Energy The energy supplied by the catabolism of ATP into ADP is constantly being used by the cell Since the supply of ATP at any given time is limited a mechanism exists to replenish it a phosphate group P is added to ADP to manufacture more ATP ADP P E gt ATP Adenosine Diphosphate Phosphate groupEnergy Adenosine Triphosphate The energy needed to attach a phosphate group to ADP is supplied mainly by the breaking down of glucose in a process called Cellular respiration Chapter 3 1 THE CELLULAR LEVEL OF ORGANIZATION Chapter 3 Anatomy and Physiology Lecture Chapter 3 2 THE CELLULAR LEVEL OF ORGANIZATIOM Functions of the Cell CDQprONT Basic unit of life Protection and Support Movement Communication Cell metabolism and energy release Inheritance How We See Cells TbF ONT Light microscope Electron microscope Scanning electron microscope SEM Transmission electron microscope TEM Summary of Cell Parts 1 Plasma membrane The outer limiting membrane separating the cell39s internal parts from the extracellular materials and external environment Cytoplasm Cytoplasm The substance that surrounds organelles and is located between the nucleus and the plasma membrane All cellular contents located between plasma membrane and nucleus Cytosol the thick semifluid portion ofthe cytoplasm which is intracellular fluid Cytoplasm Organelles Permanent structures with characteristic morphology that are highly specialized for specific cellular activities Nucleus The secretions and storage products of cells Chapter 3 3 PLASMA CELL MEMBRANE Plasma Membrane Cell Membrane or Plasmalemma is the thin barrier that separates the internal components of a cell from the extracellular material and external environment Fluid Mosaic Model of membrane structure describes the molecular arrangement ofthe plasma membrane and other membrane in living organisms Mosaic is a pattern of many small pieces fitted together Fluid mosaic model describes membrane as a mosaic of proteins floating like icebergs in a sea of lipids A Membrane Chemistry and Anatomy By weight plasma membrane of typical animal cells are about 5050 mix of proteins and lipids Proteins and Lipids are held together by noncovalent interactions Since proteins are larger and more massive than lipids however there are about 50 lipid molecules for each protein molecule Membrane Lipids a Phospholipids lipids that contain phosphorous consist of about 75 of the lipids Phospholoids line up in two parrallel rows forming a Phospholipid lipid bilayer Phospopholids are amphipathic that is they have both polar and nonpolar regions ChapterS 4 Polar part is the phosphatecontaining head which is hydrophilic mixes with water Nonpolar parts are the two fatty acid tails which are hydrophobic do not mix with water b Glycolipids Combination of Carbohydrate and Lipids consist of of membrane lipids Glycolids like phospholids are also amphipathic Functions 1 Are important for adhesion among cells and tissues 2 May mediate celltocell recognition and communication 3 Contribute to regulation of cellular growth and development C Cholesterol molecules a lipid consists of 20 of membrane lipids Cholesterol molecules are on both sides of the bilayer located among the phospholipids in animal cells The stiff steriod rings of cholesterol strengthen the membrane but decrease its flexibility Plant cell membranes lack cholesterol Bilayer is selfhealing if a needle is pushed through it and pulled out the puncture site seals Membrane Proteins Fluidmosaic model Is the modern concept ofthe plasma membrane that suggests that the plasma membrane is neither rigid nor static in structure but highly flexible and can change its shape and composition through time ChapterS 5 Membrane Proteins are classified into two categories Integral intrinsic and Peripheral extrinsic proteins a Integral Proteins extend across the phospholipid bilayer among the fatty acid tails Are Glycoproteins combination of sugar and protein Functions of Integral 1 Some integral Protein glycoprotein form tin channels ores through which certain subs flow into or out ofthe cell 2 Others act as transporter carriers to move a substance from one side ofthe membrane to the other 3 Sene as recognition sites called receptors b Peripheral Proteins do not extend across the phospholipid bilayer Are loosely bound to the inner and outer surface ofthe membrane and are easily separated from it Far less is known about Peripheral Protein than Integral Protein and their functions are not yet completely understood Generalized Functions of Membrane Proteins Channel Pore Transporter carrier Receptor Enzyme Cytoskeleton anchor Cell identity marker magmM x Marker Molecules Marker Molecules are cell surfaces molecules that allow cells to identify one another or other molecules Chapter 3 6 Examples a Glycoprotiens proteins with attached carbohydrates b Glycolipids lipids with attached carbohydrates Attachment Sites Integrins are membranebound proteins that function as attachment sites Channel Proteins Channel proteins are one or more integral proteins arranged so that they form a tiny channel through the plasma membrane Nongated ion channels are channel proteins that are always open and are responsible for the permeability of the plasma membrane to ions when the plasma membrane is at rest Ligands are small molecules that bind to proteins or glycoproteins form the Ligandgated ion channel Voltagegated ion channel When there is a charge across the plasma membrane Enzymes In The plasma Membrane Enzymes Some membrane proteins function as enzymes which can catalyze chemical reactions on either the inner or outer surface ofthe plasma membrane Carrier Proteins Carrier proteins are integral membrane proteins that move ions or molecules from one side of the plasma membrane to the other ChapterS 7 MOVEMENT THROUGH THE PLASMA MEMBRANE Extracellular materials are separated from the Intracellular materials by the Plasma membrane A Plasma membranes is Selectively Permeable that is it allows only certain substances to pass through it In order for cells to survive thing must move in and out of the cell Certain substances for example must move into the cell to support life whereas waste materials or harmful substances must be moved out Four Ways By Which Substances Can Pass Through Plasma Membrane 1 Directly through the phospholipid membrane 2 Membrane channel 3 Carrier molecules 4 Vesicles Two processes involved in movement of material are 1 Passive physical Processes the substance move on their own down a concentration gradient that is from an area where their concentration is high to an area where their concentration is low Mechanisms that move substances across a membrane without using energy released by splitting ATP The substance may also be forced across the plasma membrane by pressure from an area where the pressure is high to an area where it is low Without an expenditure of energy 2 Active Physiological Processes the substance does not move on its own The substance moves against a concentration gradient that is from an area where its ChapterS 8 concentration is low to area where it is high Mechanism that move substances across a membrane by using energy released by splitting ATP With an expenditure of energy Mechanism that move substances across a membrane by using energy released by splitting ATP Diffusion Diffusion is the movement of solutes from an area of higher concentration to an area of lower concentration in solution Net Diffusion the difference in diffusion between two regions having different concentration Eguilibrium point of even distribution Concentration Gradient is the difference between high and low concentration Viscosity is a measure of how easily a liquid flows thick solutions such as syrup Are more viscous than water Diffusion occurs more slowly in viscous solvents than in thin watery solvents Molecules moving from the highconcentration area to the low concentration area are said to move down or m the concentration gradient Note Diffusion of molecules is an important means by which substances move between the extracellular and intracellular fluids in the body Example ofdiffusion in the body The movement of oxygen from the blood ChapterS 9 into the cells and the movement of carbon dioxide from the cells back into the blood and within lungs Osmosis Osmosis is the diffusion of water solvent across a selectively permeable membrane such as plasma membrane Osmotic pressure is the force required to prevent the movement of water by osmosis across a selectively permeable membrane Tonicity Osmosis may also be understood by considering the effects of different water concentration on red blood cells cell shape a Isotonic solution a solution in which the total concentration of water molecules solvent and solute solid molecules are the same on both sides ofthe selectively permeable cell membrane The normal shape of a red blood cell is maintained Under ordinary circumstances a 09 NaCl Salt solution called a normal saline solution is isotonic for RBCs b Hypotonic Solution A solution that has a lower concentration of solutes Higher water concentration Water molecules enter the cells faster than they can leave causing the red blood cells to swell and eventually burst Rupture of red blood cells in this manner is called hemolysis A process called lysis Distilled water is a strongly hypotonic solution c Hypertonic Solution a solution that has a higher concentration of solutes and a lower concentration of water than the red blood cells Lower water Chapter 3 10 Water molecules move out ofthe cells faster than they can enter causing the red blood cells to shrink Shrinkage of red blood cells in this manner is called crenation 2 NaCl solution is Hypertonic solution Filtration Filtration is the movement of solvents water and dissolved substances solute across a selectively permeable membrane by gravity or hydrostatic water pressure From area of high pressure to an area of lower pressure Example in the body Occurs in the kidney where the blood pressure supplied by the heart forces water and small molecules like urea through thin cell membranes of tiny blood vessels and into the kidney tubules Protein molecules remain in the blood since they are too large to be forced through the cell membrane of the blood vessels Molecules of many harmful substances and waste products are small enough to be filtered They then can be eliminated in the urine MEDIATED TRANSPORT MECHANISM Mediated transport mechanism involves carrier proteins within the plasma membrane that move large watersoluble molecules or electrically charged molecules across the plasma membrane Specificity means that each carrier protein binds to and transports only a single type of molecule Competition is the result of similar molecules binding to the carrier protein ChapterS 11 Saturation means that the rate of transport of molecules across the membrane is limited by the number of available carrier proteins Three Kinds of Mediated Transport 1 Facilitated Diffusion Facilitated Diffusion Is a carriermediated process that moves substances into or out of cells from a higher to a lower concentration Does not require metabolic energy to transport substance across the plasma membrane Facilitated diffusion of glucose is greatly accelerated by insulin a hormone produced by the pancreas 2 Active Transport Some substances cannot move enter or leave into the cell either because they are too big have the wrong charge or must move against the concentration gradient Active Processes Is a mediated transport process that requiresenergy provided by ATP Active transport processes are important because they can move substances against their concentration gradients that is from lower concentration to higher concentration Example The Sodium Pump Sodium Pump maintains a low concentration of sodium ion lNal in the cytosol intracellular fluid by pumping then out against their concentration gradient Also move Potassium ions K m cells against their concentration gradient Chapter 3 12 3 Secondary Active Transport Secondary Active Transport Involves the active transport of an ion such as sodium out of cell establishing concentration gradient with a higher concentration ofthe ions outside the cells Secondary active transport indirectly uses energy obtained from splitting ATP since the ion gradients themselves are established by primary active transport pumps If Na can leak back in some ofthe stored energy can be used to transport other substances against their concentration gradient Two examples of secondary active transport a Symport Cotranspor when two substances usually Na and another substance move in the same direction across the plasma membrane Example glucose fructose and amino acids enter cells living the gastrointestinal tract and the kidney tubules via symports that use Na b Antiport countertranspor when two substances usually Na and another substance move in opposite directions across the plasma membrane eg NaCa2 NaH etc Endocytosis and Exocytosis How larger substances move across plasma membrane Endocytosis phagocytosis pinocytosis and receptormediated endocytosis are types of endocytosis Are processes that bring bulk material through plasma membrane by the formation of a vesicle ChapterS 13 Vesicle Is a membranebounded sac found within the cytoplasm 1 Pha oc tosis or quotcell eatin quot projections of the plasma membrane and cytoplasm psuedopods surround large solid particles outside the cell and then engulf them Phagocytic white blood cells and cells in other tissues engulf and destroy bacteria and other foreign substances which constitutes a vital defense mechanism to protect us from disease 2 Pinocytosis or quotcell drinkingquot the engulfed material is a tiny droplet of extracellular fluid rather than a solid 3 ReceptorMediated Endocytosis similar to pinocytosis but a highly selective process in which cells can take up specific molecules or particles Large molecules eg ligands bond with receptors specific proteins and cross the plasma membrane Example The virus that causes AIDS enters cells by attaching to a glycoprotein receptor called CD4 that is present on certain types of white blood cells Exocytosis is a reverse process it discharges substances from cells Occurs in all cells but is especially important in nerve cells which release their neurotransmitter substances by this process CYTOPLASM Cytosol Cytosol Consist of a fluid portion a cytoskeleton and cytoplasmic inclusions ChapterS 14 Cytoskeleton Support the cells and holds the nucleus and organelles in place Cytoskeleton Consists of Three Groups of Protein 1 Microtubles Are large hollow tubules composed primarily of protein units called tubulin 2 Actin filament or Microfilaments Are small fibrils about 8 nm in diameter that form bundles sheets or networks on the cytoplasm of cells 3 Intermediate filaments Are protein fibers about 10 nm in diameter that provide mechanical strength to cells Cytoplasmis lnclusions Are aggregates of chemicals either produced by the cell ortaken in by the cells ORGANELLES Nucleus Think of Brain or Control Tower The largest structure in the cell spherical or oval in shape Contains the hereditary factors of the cell called genes which control cellular structure and direct many cellular activities Contains genetic material which consists of deoxyribonucleic acid DNA Genetic material appears as a threadlike called Chromatin when cell is not reproducing Prior to cellular reproduction the chromatin shorten and coils into a rod shaped bodies called chromosomes Nucleoli are present inside the nucleus ChapterS 15 Are aggregate of protein DNA and RNA that are not bounded by a membrane Are sites of assembly of ribosomes which contain a type of RNA called ribosomal RNA plays a key role in protien synthesis Nucleoli disperse and disappear during cell division Ribosomes Think of the Kitchen Consists of ribosomal Ribonucleic acid rRNA and ribosomal proteins They occur free singly or in cluster Are the sites of protein synthesis Endoplasmic Reticulum ER A system of membraneenclosed channels of varying shapes called cisterns or cisternae ls continuous with the nuclear envelope Provides a surface area for chemical reactions and various products are transported from one portion of the cell to another via the ER Divided into two types based on its association with ribosomes 1 Granular rou h ER Studded or attached with ribosomes Synthesize proteins Temporary storage area for newly synthesized molecules ChapterS 16 2 A ranular smooth ER Do not contain ribosomes Synthesize fatty acid phospholipid and steroid Can inactivate or detoxify a variety of channels including alcohol pestiudes and carcinogens Golgi Complex Think of a post office Consists of four to six stacked flattened membranous sacs cisternae referred to as g medial and trans cisternae Process sort and deliver proteins within the cell Secretes proteins and lipids and forms lysosomes Mitochondria Think of Powerhouse Are called the quotPowerhousesquot of the cell as they function in energy generating Active cells such as muscle liver and kidney tubule cells have large number of mitochondria because of their high energy expenditure Within mitochondria energy is transferred from carbon compounds such as glucose to ATP Mitochondria is composed of two membranes a The outer mitochondria membrane is smooth but the inner membrane is arranged in a series of folds called cristae b The central cavity of a mitochondrion enclosed by the inner membrane and cristae is called the matrix Chapter 3 17 Lysosomes Think of Suicide packets Are formed from Golgi complexes Function in Intracellular Digestion Contain digestive enzymes digest wornout organelles by a process called autoghagy selfeat Digests injured cell by a process called autolysis selfdestruct Lysosomes are thereby called quotsuicide packetsquot Are found in large numbers in white blood cells which carry on phagocytosis cell eating Functions in Extracellular Digestion Prior to fertilization the head of a sperm cell releases lysosomal enzymes capable of digesting a barrier around the egg so that the sperm cell can penetrate it lnvolved in bone removal especially during the growth process Peroxisomes Similar in structure to lysosomes but smaller Are abundant in liver cells Contain several enzymes eg catalase involved in the metabolism of hydrogen peroxide Catalase 2H202 2H20 202 Hyrdogen Water Oxygen Chapter 3 18 Peroxide Hydrogen peroxide is toxic to body cells Centrosome and Centrioles A dense area of cytoplasm generally spherical and located near the nucleus is called centrosome centrosphere Within the centrosome is a pair of cylindrical structure called centrioles Centrioles assume an important role in cell reproduction by helping to organize the mitotic spindle Flagella and Cilia These cellular projections have the same basic structure and are used in movement If projection are few typically occurring singly or in pairs and long they are called flagella lfthey are numerous and hairlike they are called The flagellum on a sperm cell moves the entire cell The cilia on cells of the respiratory tract move foreign matter trapped in mucus along the cell surfaces toward the throat for elimination CELL INCLUSIONS Are large and diverse group of chemical substances produced by cells Examples 1 Melanin a pigment stored in certain cells ofthe skin hair and eyes Chapter 3 19 It protects the body by screening out harmful ultraviolet rays from the sun 2 Glycogen a polysaccharide that is stored in the liver skeletal muscle fibers cells and the vaginal mucosa When the body requires quick energy liver cells can break down the glycogen into glucose and release it 3 Lipids are stored in adipocytes fat cells may be decomposed for producing energy Extracellular materials Are substances that lie outside the plasma membrane They provide support and a medium for the diffusion of nutrients and wastes Some like hyaluronic acid and chondroitin sulfate are amorphous without shape Others like collagenous reticulae and elastic fibers are fibrous OVERVIEW OF CELL METABOLISM Cell Metabolism Is the sum of all the catabolic decomposition and anabolic synthesis reactions in the cell Glycolysis Converts the glucose to Pyruvic acid Aerobic respiration Occurs when oxygen is available Anaerobic respiration Occurs without oxygen and includes the conversion of Pyruvic acid to lactic acid Chapter 3 20 GENE ACTION Gene is a group of nucleotides on a Deoxyribonucleic Acid DNA molecule that serves as the master mold for manufacturing a specific protein Cells are basically protein factories that constantly synthesize large numbers of diverse proteins Proteins in turn determine the physical and chemical characteristics of cells and therefore of organisms Other proteins serve as hormone antibodies and contractile elements in muscle tissue Others are enzymes Deoxyribonucleic Acid DNA is a substance present in nuclei of cells consisting of phosphoric acid a sugar and nitrogenous bases It is a nucleic acid localized principally in the chromosomes lt regulates protein synthesis and is the key molecule of the genes which give each cell its hereditary qualities and characteristics PROTEIN SYNTHESIS Production of all the Proteins in the body is underthe control of DNA Building blocks of DNA are nucleotides containing Adenine A Thymine T Cytosine C and Guanine G Triplet every three nucleotides code for an amino acid and amino acids are the building block of proteins Genes Are all ofthe triplets required to code for the synthesis of a specific protein Chapter 3 21 Messenger RNA mRNA Travels from the nucleus to ribosomes in the cytoplasm where the information in the copy is used to construct a protein ie translation Transfer RNA tRNA Carry the amino acid to the ribosome Two rinci alste sin roteins nthesis 1 mm and 2 Translation Transcription is the process by which genetic information encoded in DNA is copied by a strand of RNA called messenger mRNA Occurs in the Nucleus By using specific portion ofthe cell39s DNA as a template base the genetic information stored in the sequence of nitrogenous bases of DNA is rewritten so that same information appears in the nitrogenous bases of mRNA Genetic information in DNA is copied to mRNA When RNA synthesis is complete mRNA leaves the nucleus and enters the cytoplasm where translation occurs Translation is the process whereby information in the nucleotide sequence of mRNA specifies the amino acid sequence of a protein Occurs in the Cytoplasm Just as DNA provides the template for mRNAto be made so mRNA provides a template for protein synthesis Transcription Translation DNA RNA Protein Chapter 3 22 CELL LIFE CYCLE Cell Life Cycle Includes the changes a cell undergoes from the time it is formed until it divides to produce two new cells Two Stages of Cell Life Cycle 1 An lnterphase 2 A Cell Division Stage llNTERPHASE Metabolic Phase lnterphase is a phase when a cell is between divisions Consist of three distinct phases G S and 62 The so called resting period between cell divisions Represents 90 of the cell cycle A period of great metabolic activity a Dispersal and Replication synthesis or duplication of DNA occurs to ensure that each daughter cell receives the same genetic material as parent It is during this stage that the replication synthesis of chromosomes occurs and the RNA and protein needed to produce structures required for doubling all cellular components are manufactured Generation after generation as a result of DNA replication and cell division DNA is copied with great accuracy Some mistakes in copying may be of no consequence but some may be quite serious and may result in sicklecell anemia and several forms of cancer Chapter 3 23 CELL DIVISION Mitosis Cell division involves two major events 1the division of the nucleus to form two new nuclei 2 the division of the cytoplasm to form two new cells Mitosis is the distribution of the two sets of chromosomes into two separate and equal nuclei following the replication of the chromosome of the parent nucleus Somatic Cells Includes all human cells except the sex cells Contains 46 chromosomes referred to as diploid 46 chromosomes in somatic cells are organized into 23 pairs of chromosomes Twentytwo pairs are called Autosomes Each member of an autosomal pair of chromosome looks structurally alike and together they are called a Homologous pair of chromosomes Sex Chromosomes are the remaining two pairs 1 X chromosome female looks alike XX 2 Y chromosome male does not look alike XY 1 Prophase The first phase of Mitosis Formation of mitotic apparatus Asters Spindles Centrioles and Microtubules a Chromatin shortens and coils into chromosomes Chapter 3 24 Each prophase quotChromosomequot is actually composed of a pair of structures called chromatids A chromatid is a complete chromosome consisting of a double stranded DNA molecule and each is attached to its partner by a small spherical body called a centromere b Nucleoli and Nuclear envelope begin to break up and their components are resorbed into the endoplasmic reticulum c Chromosomal microtubule and continuous microtubule together called the mitotic spindle form between the separating centrioles d The centrioles pairs move to opposite poles ofthe cell and radiate an array of microtubules called an aster little star 2 Metaphase Separation of sister chromatids a The centromeres ofthe chromatid pair line up on the equatorial plane ofthe cell b The centromeres of each chromatid pair form a chromosomal microtubule that attaches the centromere to a pole ofthe cell 3 Anaphase Movement of the Chromosomes a Centromeres divide and identical sets of chromosomes move to opposite poles of cell b considered the shortest phase Chapter 3 25 4 Telophase Reformation of nuclei Nuclear membrane reappears and encloses chromosomes Chromosomes resume chromatin form Nucleoli reappear Mitotic spindle disappears Centrioles duplicate End of mitosis rum 00 pro Cytokinesis Partitioning the cytoplasm a Cleavage furrow forms around equatorial plane of cell b Separates cytoplasm into two separate and equal portions c Two daughter cells are formed REPRODUCTIVE CELL DIVISION Gametes are specialized sex cells the ovum produced in the female gonads ovaries and the sperm produced in the male gonads testes Fertilization the union and fusion of gametes Zygote a single cell formed as a result of fertilization Somatic cells have 46 chromosomes in their nuclei or 23 pairs of chromosomes and referred to as diploid cells 2n Reproductive cells gametes have 23 chromosomes and are referred to as haploid cells n Chapter 3 26 Homologous Chromosomes or Homologous are two chromosomes that belong to a pair in a diploid cell In human diploid cells 22 ofthe 23 pairs of chromosome are morphologically similar and are called autosomes 1 to 22 pairs of chromosome 23rd pair of chromosome Autosomes Sex chromosomes The last pairs 23rd of chromosomes is called Sex Chromosomes and designated as X and Y Male 6 XY Sperm is either X or Y Female6 XX Egg can only be X MEIOSIS Reduction of chromosomes Occurs only in the development of gametes and it results in the production of cells that contain only 23 chromosomes Spermatogenesis is the formation of haploid sperm cells in the testes of the male Oogenesis is the formation of haploid ova eggs in the ovaries of the female Meiosis occurs in two successive nuclear divisions referred to as reduction divisionlMeiosis I and eguatorial division Meiosis Ill Chapter 3 27 l REDUCTION DIVISION MEIOSIS I 1 a Interphase Replication of chromosomes similar to that of Mitosis Reduction division begins once chromosomal replication is complete Reduction Division Consists of Four phases b Prophase I 1 Chromosomes shorten and thicken 2 Nuclear membrane and nucleoli disappear 3 Centrioles replicate and mitotic spindle appears Unlike the Prophase of Mitosis in Prophase l of Meiosis Chromosomes become arranged in homologous The pairing is called Synpasis The four chromatids of each homologous pair are referred to as a Tetrad 4 Crossingover occurs portions of one chromatid may be exchange with portions of another This process among others permits an exchange of genes among chromatids so that subsequent daughter cells produced are unlike each other genetically and unlike the parent cell that produce them c Metaphase I 1 Paired chromosomes line up along the equatorial plane of the cell with one member of each pair on either side Recall that there is no pairing of homologous chromosomes during the metaphase of mitosis Chapter 3 28 d Anaphase 1 Separation ofthe members of each homologous pair with one member of each pair moving to an opposite pole ofthe cell During Anaphase l unlike mitotic Anaphase the centromeres do not split and the paired chromatids held by a centromere remain together e Telophase and Cytokinesis are similar to those of mitosis II E uatorial Division Meiosis II a Interphase The interphase between reduction division and eguatorial division is either brief or lacking altogether There is no replication of DNA b Prophase ll Metaphase ll Anaphase II and Telophase II are similar to those that occur during mitosis During equatorial division the two haploid daughter cells undergo mitosis and the net result is four haploid cells All four haploid cells develop into sperm cells in the testes of the male Only one of the haploid cells has the potential to develop into an ovum in the female The otherthree become structures called polar bodies that do not function as gametes Comparison between Mitosis and Meiosis ChapterS 29 ABNORMAL CELL DIVISION CANCER CA Tumor Growth or Neoplasm the excess of tissue that develops when cells in some area ofthe body duplicate without control Oncology the study of tumor Oncologist a physician who specializes in tumor Malignant tumo a cancerous growth Benign tumor growth a noncancerous growth Metastasis the spread of cancer from its primary site Carcinogens are chemicals or environmental agents that can produce cancer Oncogenous are genes that can transform normal cells into cancerous cells CELLS AND AGING Aging is a normal process accompanied by a progressive alteration ofthe body39s homeostatic adaptive response Geriatrics the specialized branch of medicine that deals with the medical problems and care of elderly persons Clinical Application Types of Cancer 1 Carcinomas Malignant tumors that arise from epithelial cells 2 Melanomas Cancerous growths of melanocytes skin cells that Chapter 6 THE SKELETAL SYSTEM BONE TISSUE Chapter 6 Anatomy and Physiology Lecture Chapter 6 THE SKELETAL SYSTEM BONE TISSUE Bone Osseous Tissue forms most of the skeleton Skeletal System the framework of bones and cartilage that protects our organs and allows us to move Osteology is the study of bone structure and treatment of bone disorders Without the skeletal system we would be unable to perform movements such as walking or grasping The slightest jar to the head or chest could damage the brain or heart It would even be impossible to chew FUNCTIONS OF THE SKELETAL SYSTEM 1 Support Provides a framework for the body supports soft tissues and provides a point of attachment for many muscles 2 Protection The brain is protected by the cranial bones the spinal cord by the vertebrae the heart and lungs by the rib cage and internal reproductive organ by the pelvic bones 3 Movement Facilitation In conjunction with the muscles 4 Storage Store several minerals eg calcium and phosphorus that can be distributed to other parts ofthe body upon demand are stored Lipids stored in cells of yellow marrow are an important source of chemical energy Yellow Marrow consists primarily of adipose cells and a few scattered blood cells 5 Blood Cell Production Red marrow in certain bones is capable of producing blood cells a process called Hematopoiesis or Chapter 6 3 CARTILAGE Three Types of Cartilage 1 Hyaline Cartilage 2 Fibrocartilage 3 Elastic Cartilage Most ofthe bones in the body develop from Hyaline cartilage Specialized Cells of Hyaline Cartilage 1 Chondroblasts Cells that produce new cartilage matrix 2 Chondrocyte A Chondrocyte surrounded by matrix Perichondrium Is a doublelayered connective tissue sheath covering most cartilage Articular Cartilage Is the cartilage covering the ends of bones where they come together to form joints BONE ANATOMY Bones are classified according to their shape as ong m M or irregular Long Bones Are longer than they are wide Most ofthe bones ofthe upper and lower limbs are long bones Short Bones Are about as broad as they are long Are nearly cubeshaped or rounded mainly of the wrist carpals and ankle tarsals bones Chapter 6 4 Flat Bones Have a relatively thin flattened shape and are usually cuned Bones ofthe skull ribs the breastbone sternum Shoulder blade scapulae Structure of a Typical Long Bone A typical bone consists of the following parts 1 Diaphysis The shaft or long main portion ofthe bone Composed mainly of Compact Bone bone matrix with few small spaces Epiphyses The extremities or ends ofthe bone Consists of Cancellous or Spongy bones Epiphyseal plate ls hyaline cartilage located between the epiphysis and diaphysis It is where growth in bones occur Articular Cartilage a thin layer of hyalin cartilage covering the epiphysis where the bone forms a joint with another bone Reduces friction and absorbs shock at freely movable joints Periosteum A dense white fibrous covering around the surface of the bone not covered by articular cartilage Consists of m layers a Fibrous layer composed of connective tissue containing blood vessels lymphatic vessels and nerves that pass into the bone outer layer b Osteogenic Layer contains elastic fibers blood vessels Chapter 6 5 l Endosteum osteoprogenitor osteogenic cells osteoclasts and osteoblasts inner layer Periosteum is essential for bone growth repair and nutrition and also serves as a point of attachment for ligaments and tendons Medullary or Marrow Cavity The space within the diaphysis that contains the fatty yellow marrow in adults Yellow marrow consists primarily of fat cells and a few scattered blood cells Yellow marrow functions in fat storage adipose tissue Is a connective tissue membrane that lines the internal surfaces of all cavities within bone Is a single layer of cells which includes osteoblasts osteoclasts and osteochondral progenitor Note Bone is not completely solid In fact all bone has some spaces between its hard components The spaces provide channels for blood vessels that supply bone cells with nutrients The spaces also make bones lighter BONE HISTOLOGY Microscopic structure of bone tissue Bone consists of extracellular bone matrix and bone cells Bone Matrix Mature bone by weight consists of 35 organic and 65 inorganic material Chapter6 6 Organic Material Consists of Collagen and Proteoglycans Inorganic Material Consists of a Calcium Phosphate crystal called Hydroxyapatite Bone Cells 1 Osteoblasts Are associated with bone formation Have extensive endoplasmic reticulum and numerous ribosomes Ossification or Osteogenesis Is the formation of bone by osteoblast 2 Osteocytes Are mature bone cells Are the principal cells of bone tissue Lacunea Are spaces occupied by the osteocyte cell bodies Canaliculi little canalsl Are spaces occupied by the osteocyte cell processes 3 Osteoclasts Develop from circulating monocytes one type of white blood cells Are found around the surfaces of bone Function in bone resorption degradation Important in the development growth maintenance and repair of bone Chapter6 7 Origin of Bone Cells Connective tissue develops embroyologically from mesenchymal cells Stem Cells Have the ability to replicate and give rise to more specialized cell types Osteochondrial progenitor cells Are stem cells that have the ability to become osteoblasts and chondrioblasts Note Osteoblasts are derived from osteochondral progenitor cells and osteocytes are derived from osteblasts Woven and Lamellar Bone According to the organization of collagen fibers within the bone matrix bone tissue is classified as a Woven bone or b Lamellar bone aWoven bone Collagen fibers are randomly oriented in many direction b Lamellar bone ls mature bone that is organized into thin sheets or layers called lamellae Cancellous and Compact Bone Bone woven or lamellar are classified according to the amount of bone matrix relative to the amount of space present within the bone Cancellous bone has less matrix and more space while Compact bone has more matrix and less space Chapter 6 8 Cancellous Bones Consists of interconnecting rods or plates of bones called trabeculae Between the trabeculae are spaces that in life are filled with bone marrow and blood vessels Note Cancellous bone is sometimes called Spongy Bones because of its porous appearance Compact Bone Compact bone is denser and has fewer spaces than Cancellous bone Perforating Volkmann39s Canals through which the blood vessels and nerves from the periosteum penetrate the compact bone Central Haversian Canals run longitudinally through the bone Blood vessels and nerves of medullary cavity marrow cavity perforating Volkmann39s canals and central Haversian canals connect each other Concentric Lamellae rings of hard calcified intercellular substance Lacunae little lake are small spaces forward between the Lamellae Contains Osteocytes Osteocytes are mature osteoblasts that no longer produce new bone tissue and function to support daily cellular activities of bone tissue Canaliculi radiate in all directions from the Lacunae as minute canals Contain slender processes of osteocytes and extracellular fluid Help to form an intricate network throughout the bone Chapter6 9 Circumferential lamellae Are flat plates that extend around the bone that forms the outer surfaces of compact bones Intestitial lamellae Are remnants of concentric or circumferential lamellae that were partially removed during bone remodeling BONE DEVELOPMENT Ossification or Osteogenesis is the process by which bone forms in the body The quotskeletonquot of a human embryo is composed of fibrous membranes and hyaline cartilage Both are shaped like bone and provide the medium for ossification Ossification begins around the sixth or seventh week of embryonic life and continues throughout adulthood Two Kinds of Bone Formation 1 lntramembranous Ossification lntramembranous Ossification Is the formation of bone directly on or within the fibrous membranes It is the most simpler and direct form of bone formation Examples Skull bones The clavicles collarbones a Center of Ossification Custer site of osteoblasts in a fibrous membrane b Calcification deposition of calcium salts Trabecula when a cluster of osteoblasts is completely surrounded by Chapter 6 10 the calcified matrix 2 Endochondral Ossification Endochondral lntracartilaginous Ossification is the replacement of cartilage by bone Best observed in a long bone Proceeds as follows a Development ofthe Cartilage Model At the site of bone formation site where bone is going to form Mesenchymal cells crowd together in the shape ofthe future bone Mesenchymal cells differentiate into chondroblasts which form the hyaline cartilage model Perichondrium develops around the cartilage model b Growth ofthe Cartilage Model Two types of growth are involved here i Interstitial growth a growth from within results in an increase in length ii Appositional growth a growth by which matrix is deposited on its surface from outside c Development ofthe Primary Ossification Center Near the middle of the model capillaries of the periosteum grow into the disintegrating calcified cartilage m The vessels Associated osteoblasts Osteoclasts Red Marrow cells are known as Peristeal Bud On growing into the cartilage model the capillaries produce a Primary ossification center Primary Ossification Center Is a region where bone tissue will Chapter6 11 replace most of the cartilage d Development ofthe Diaphysis and Epibhvsis Diaphysis shaft which was once a solid mass of hyaline cartilage is replaced by compact bone the central part of which contains a real marrowfilled medullary cavity Secondary Ossification Center develop usually around the time of birth when blood vessels epiphyseal arteries enter the epiphyses Chondroblast a cartilage forming cell Chondroclast a cartilage destroying cell Chondrocyte a mature cartilage cell BONE GROWTH Bones increase in size only by Appositional Growth Unlike Cartilage bone cannot grow by Interstitial Growth Growth of Bone Length Long bones and bony projections increase in length because ofgrovvth at the Epiphyseal Plate Note Growth at the epiphyseal plate involves the formation of new cartilage by interstitial cartilage growth followed by appositional bone growth on the surface ofthe cartilage Four Zones of the Epiphyseal Plate a Zone of Resting Cartilage is near the epiphysis and consists of small chondrocytes that are scattered irregularly throughout the Chapter 6 12 intercellular matrix Do not function in bone growth they anchor the epiphyseal plate to the bone of the epiphysis b Zone of Proliferating Cartilage consists of slightly larger chondrocytes arranged like stack of plates or coins Functions to make new chondrocytes by cell division to replace those that die at the diaphyseal surface of the epiphyseal plate c Zone of Hypertrophic Cartilage or Maturing Cartilage consists of even larger chondrocytes that are also arranged in columns with the more mature cells closer to the diaphysis d Zone of Calcified Cartilage is only a few cells thick and consists mostly of dead cells because the intercellular matrix around them has calcified Calcified that is minerals are deposited within it Nutritive materials required by the cartilage cells can no longer diffuse through the intercellular substance and this may cause the cartilage cells to die Metaphysis is the region between the diaphysis and epiphysis of a bone where the calcified matrix is replaced by bone Growth of Articular Cartilage Epiphyses increase in size because of growth at the articular cartilage Growth at the articular cartilage increases the size of bones that do not have an epiphysis such as short bones Note When the epiphyses reach their full size the growth of cartilage and its replacement by bone ceases The articular cartilage however persists throughout life and does not become ossified as does the epiphyseal plate Chapter 6 13 Growth of Bone Width Long bones increase in width diameter and other bones increase in size orthickness because of appositional bone growth beneath the periosteum Factors Affecting Bone Growth 1 Nutrition Vitamin D ls necessary for the normal absorption of calcium from the intestine Vitamin C ls necessary for collagen synthesis by osteoblasts 2 Hormones Growth Hormones From the anterior pituitary increases general tissue growth including overall bone growth by stimulating interstitial cartilage growth and appositional bone growth Thyroid Hormones Is required for normal growth of all tissues including cartilage therefore a decrease in this hormone can result in decreased size of individual Sex Hormones In uences bone growth Estrogen a class of female seX hormones and Testosterone a male seX hormone initially stimulate bone growth which accounts for the burst of growth at the time of puberty when production of those hormones increases Note a The homeostasis of bone growth and development depends on a balance between bone formation and resorption b Normal growth depends on calcium phosphorus and vitamins especially vitamin D and is controlled by hormones that are responsible for bone mineralization and resorption Chapter 6 14 BONE REMODELING Bone Remodeling Is the process by which old bones are replaced by new bones Osteoclasts remove old bones Osteoblasts deposit new bones Note Remodeling is also responsible for the formation of new osteons in compact bone in two ways 1 Within already existing osteons osteoclasts enter a central canal through the blood vessels and begin to remove bone from the center of the osteon resulting in an enlarged tunnel through the bone 2 A few osteoclasts in the perioteum remove bone resulting in groove formation along the surface of the bone BONE REPAIR As a living thing bone undergoes repair if damages Four Major Steps of Bone Repair 1 Hematoma Formation Hematoma forms when bones is fractured the blood vessels in the bone and surrounding periosteum are damaged 2 Callus Formation Callus is a mass of tissue that forms at a fracture site and connects the broken ends of bone 3 Callus Ossification Like the cartilage models formed during fetal development the cartilage in the external callus is replaced by woven cancellous bone through endochondral ossification Chapter 6 15 4 Remodeling of Bone Filling the gap between bone fragments with an internal callus of woven bone EXERCISE AND THE SKELETAL SYSTEM Bone can alter its strength in response to mechanical stress Bone that is stressed produces a minute electric current by way of it mineral salt crystals Piezoelectric effect that stimulates osteoblastic activity Regular exercise can stimulate osteoblasts and inhibit osteoclasts AGING AND THE SKELETAL SYSTEM The principal effect of aging is a loss of calcium from bones which may result in Osteoporosis Another effect is a decreased production of organic matrix which makes bones more susceptible to fracture DEVELOPMENTAL ANATOMY OF THE SKELETAL SYSTEM Bones form from mesoderm by intramembranous or endochondral ossification Extremities develop from limb buds which consists of mesoderm and ectoderm Notochord is a flexible rod of tissue that lies in a position where the future vertebral column will develop DISORDERS HOMEOSTATIC IMBALANCES Chapter 6 16 a Osteoporosis is a decrease in the amount and strength of bone tissue owing to decrease in hormone output decreased level of estrogens b Vitamin Deficiencies i Rickets a deficiency of vitamin D in children Characterized by an inability of the body to transport calcium and phosphorus from the gastrointestinal tract into the blood for utilization by bones ii Osteomalacia Deficiency of Vitamin D in adults causes the bones to give up excessive amounts of calcium and phosphorus This is called Demineralization c Paget39s Disease is the irregular thickening and softening of bones related to a greatly accelerated remodeling process d Osteomyelitis is a term for the infectious diseases of bones marrow and periosteum It is frequently caused by quotstaphquot bacteria e Fracture FXl any break in a bone Closed reduction restoration of fracture to normal position by manipulation without surgery Open reduction exposed by surgery before the break is rejoined Classification of Bone Fractures A Clinical Focus Chapter 6 17 10 11 12 13 Partial Incomplete a fracture in which the break across the bone is incomplete Complete a fracture in which the break across the bone is complete so that the bone is broken into two or more pieces Closed Simplel a fracture in which the bone does not breakthrough the skin Open Compound a fracture in which the broken ends of the bone protrude through the skin Comminuted a fracture in which the bone is splintered at the site of impact and smaller fragments of bone are found between the two main fragments Greenstick a partial fracture in which one side of the bone is broken and the other side bends occurs only in children Spiral a fracture in which the bone is usually twisted apart Transverse a fracture at right angles to the long axis ofthe bone Impacted a fracture in which one fragment is firmly driven into the other Pott39s a fracture ofthe distal end ofthe fibula with serious injury ofthe distal tibial articulation Colle39s a fracture of the distal end ofthe radius in which the distal fragment is displaced posteriorly Displaced a fracture in which the anatomical alignment ofthe bone fragments is not preserved Nondisplaced a fracture in which the anatomical alignment ofthe bone fragments is preserved THE SKELETAL SYSTEM THE AXIAL SKELETON GROSS ANATOMY Chapter 8 Anatomy and Physiology Lecture APPENDICULAR SKELETON Appendicular Skeleton includes bones of the A B C D Pectoral Girdles shoulder Pelvic Girdles Hip Upper Extremities and Lower Extremities PECTORAL SHOULDER GIRDLE Attach the bones of the Upper Extremities to the Axial Skeleton Have no articulation with the vertebral column Although the shoulderjoints are not very stable they are freely movable and thus allow movement in many directions Each of the two Pectoral Girdles consist of two bones 1 A clavicle and 2 A scapula Clavicle or Collar Bones Are long slender bones with a double cunature Are the anterior component and articulates with the sternum at the Sternoclavicular 39oint Sternal Extremity is the medial end of the clavicle where it articulates with the sternum Acromial Extremity is the lateral end ofthe clavicle where it articulates with the Acromion of the scapula a joint called Acromioclavicular 39oint 2 Scapula or Shoulder Blades Are large triangular flat bone Are the posterior component and articulate with clavicle and humerus Situated in the posterior part of the thorax between the levels of the second and seventh ribs Spine is a sharp ridge that runs diagonally across the posterior surface of the flattened triangular body Acromion is the end of the spine that projects as a flattened expanded process easily felt as the high point ofthe shoulder Glenoid Cavity Fossal a depression inferiorto Acromion This cavity articulates with the head of the humerus to form the shoulder 39oint Medial Vertebral Border is the thin edge of the body near the vertebral column Lateral Axillary Border is the thick edge closer to the arm UPPER EXTREMITY Consist of 60 bones Each upper extremity includes 1 Humerus in the arm 2 Ulna and Radius in the forearm 3 Carpals wrist bones 4 Metacarpals palm bones 5 Phalanges in the fingers ofthe hand Humerus or Arm Bone Is the longest and largest bone of the upper extremity Articulates proximally with the scapula and distally at the elbow with both ulna and radius Proximal end ofthe Humerus consists of Head articulates with the glenoid cavity of the scapula Anatomical Neck an oblique groovejust distal to the head and the site of the epiphyseal plate Greater Tubercle a lateral projection distal to the neck It is the most palpable bony landmark of the shoulder region Lesser Tubercle an anterior projection Between these tubercles runs an lntertubercular sulcus bicipital groove Surgical Neck a constricted portion just distal to the tubercles Named because of its liability to fracture Body shaftj cylindrical at the proximal end and gradually becomes triangular flattened and broad at the distal end Deltoid Tuberosity a roughened Vshaped area at the middle portion of the shaft Senes as a point of attachment for the deltoid muscle Distal end ofthe Humerus Consists of Capitulum a rounded knob that articulates with the head ofthe radius Radial Fossa a depression that receives the head ofthe radius when the forearm is flexed Trochlea a pulleylike surface that articulates with the ulna Coronoid Fossa an anterior depression that receives part of the ulna when the forearm is flexed Olecranon Fossa a posterior depression that receives the Olecranon of the ulna when the forearm is extended Medial and Lateral Epicondyle are rough projections on either side ofthe distal end to which most muscles of the forearm are attached UIna and Radius Ulna is the medial bone of the forearm located at the little finger side Proximal end ofthe Ulna Consists of Olecranon Olecranon Processl forms the prominence of the elbow Trochlear lsemilunarl Notch a curved area between the olecranon and the coronoid process The trochlea of the humerus fits into this notch Radial Notch a depression located laterally and inferiorly to the trochlear notch lt receives the head ofthe radius Distal end of Ulna Consists of M separated from the wrist by a fibrocartilage disc Styloid Process on the posterior side ofthe distal end m is the lateral bone of the forearm located on the thumb side Proximal end of Radius Consists of Head is discshaped and articulates with the Capitulum of the humerus and radial notch of the ulna Radial Tuberositv a roughened raised area on the medial side Is a point of attachment forthe biceps brachii muscle Distal end of Radius Consists of Styloid Process on the lateral side Ulnar Notch on the medial side but concave for articulation with the distal end ofthe ulna Carpals Metacarpals and Phalanges Carpus or wrist consists of eight small bones the carpals united to each other by ligaments 4 Bones each in two transverse rows named for their shapes Lateral to medial position in Anatomical position Thumb i Scaphoid resembles a boat J ii Lunate resembles a crescent moon in nits anteroposterior aspect iii Triquetrum has three articular surfaces Small finger iv Pisiform peashaped small finger little finger Thumb i Trapezium foursided J ii Trapezoid foursided iii Capitate rounded projection the head articulate with the lunate Small finger iv Hamate named for the large hookshaped projection on anterior surface Metacarpus metaafter with five bones that constitute the palm ofthe hand Each bone consist of a proximal base medial shaft and distal head The bones are numberlto v starting with the lateral bone big short bone in anatomical position The heads of the metacarpals are commonly called the quotknucklesquot and are readily visible when the fist is clenched Phalanges with 14 bones that constitute the bones of the fingers Phalanx a single bone of the finger or toe Each Phalanx consists of a Proximal Medial m and Distal First digit thumb has two phalanx called the Pollex thumb Each of the remaining four digits index finger middle finger ring finger and little finger has three phalanx PELVIC HIP GIRDLE Pelvic hip Girdle consist of the two coxal bones or hipbones Provides a strong and stable support for the lower extremities on which the weight of the body is carried Pubic Symphysis where the two coxal bones hip bones unite Pelvis a basinlike structure formed by the unification of sacrum coccyx and the two coxal hip bones A newborn39s Coxal hip bones consists three separate components Ilium Pubis and schium Acetabulum area of fusion for the three components ilium pubis and ischium as they eventually fuse into one llium is the largest of the three subdivisions of the coxal bone LOWER EXTREMITY Are composed of bones Femur in thethigh Patella kneecap Fibula and Tibia in the leg Tarsals ankle bone Metatarsals and Phalanges in the toes cnanooN x 1 Femurthighbone1 is the longest and heaviest bone in the body Head is the proximal end that articulates with acetabulum of the coxal bone Greater Trochanter and Lesser Trochanter are projections that sene as points of attachment for some ofthe thigh and buttock muscles Linea Aspera a rough vertical ridge on the posterior surface of diaphysis shaft of the femur Pathologic changes in the angle of the neck of the femur resulting in abnormal posture of the lower limbs a quotKnockkneequot condition a decreased angle b quotBowlegquot condition abnormally large angle Both conditions place an abnormal strain on the knee joints Patella Patella jkneecapj is a small triangular bone anterior to the knee joint Base the broad superior end Apex the pointed inferior end Tibia and Fibula Tibia shinbonej is the larger medial bone of the leg Lateral Condyle and Medial Condyle articulate with the condyles of the Femur Fibula is parallel and lateral with the fibula Head on the proximal end articulates with the inferior surface of the lateral conder of the tibia below the level ofthe kneejoint Lateral Malleolus on the distal end articulates with the talus bone of the ankle Pott39s Fracture a fracture of the lower end of the fibula with injury to the tibia articulation Tarsals Metatarsals and Phalanges Tarsus is a collective designation for the seven bones of the ankle called Tarsals Talus and Calcaneus are located on the posterior part ofthe foot Cuboid Navicular and three Cuneiform bones first medial second intermediate and third lateral cuneiform are located on the anterior part of the foot Talus the uppermost tarsal bone is the only bone of the foot that articulates with the Fibula and tibia Metatarsus consists Offl metatarsal bones numbered l to V from medial to later position Like Metacarpals ofthe palm ofthe hand each Metatarsal consist of a proximal Base medial shaft and a distal Head Phalanges of the foot resemble those ofthe hand both in number and arrangement THE SKELETAL SYSTEM THE AXIAL SKELETON Chapter 7 Anatomy and Physiology Lecture THE SKELETAL SYSTEM THE AXIAL SKELETON Skeletal System forms the framework ofthe body TYPES OF BONES FOUR PRINCIPAL BASED ON SHAPE A Long Bones have greater length than width and consist of a diaphysis and a variable number of epiphyses Examples Bones of the thighs legs toes arms forearms and fingers B Short Bones Are somewhat cubeshaped and nearly equal in length and width Examples Wrist and ankle bones C Flat Bones Are generally thin and composed of two more or less parallel of compact bone enclosing a layer of spongy bone Examples Cranial bones which protect the brain sternum and ribs which protect organs in the thorax and scapulas D Irregular Bones Have complex shapes and cannot be grouped into any of the three categories Example Vertebrae and certain facial bones Two Additional Bones Based on Location A Sutural orWormian Bones Are small bones between joints of certain cranial bones B Sesamoid Bones Are small bones in tendons where considerable pressure develops for instance in the wrist Examples Patellas kneecaps DIVISIONS OF THE SKELETAL SYSTEM Adult human skeleton usually consist ofamp named bones Tubercle or Process Where ligament or tendon attached Smooth Surface Part of a joint and was covered with articular cartilage Foramen Was occupied by nenes or blood vessel Sinuses Contained mucous membraneline air spaces Grouped in Two Principal Division 1 Axial Skeleton Consists ofthe bones that lie around the axis ribs breastbone hyoid bone bones ofthe skull and backbone 2 Appendicular Skeleton contains the bones ofthe free appendages upper and lower extremities limbs plus the girdles which connect the extremities to the axial skeleton Number of Named Bones Listed By Category Note Complete Skeleton and Named Bones Region of the Skeleton Axial Skeleton A Skull moom 1 Cranium 2 Face Hyoid Auditory Ossicles 3 in each ear Vertebral Column Thorax 1 Sternum 2 Ribs Appendicular Skeleton Pectoral shoulder girdles Clavicle Scapula Upper Extremities Humerus Ulna Radius Carpals Metacarpals Phalanges Pelvic Hip Girdle Coxal pelvic or hip bone Lower Extremities Femur Fibula Tibia Patella Tarsals Metatarsals Number of bones A l 0 Total 206 THE AXIAL SKELETON SKULL Contains 22 bones Rests on the superior end ofthe vertebral column Composed of m sets of bones a Cranial Bones enclose and protect the brain 8 Cranial Bones Frontal Bone Parietal Bones 2 Temporal Bones 2 Occipital Bone Sphenoid Bone Ethmoid Bone b Facial Bones constitutes the facial structure Nasal Bones 2 Maxillae Zygomatic Bones 2 Mandible Lacrimal Bones 2 Palatine Bones 2 Inferior Nasal Conchae 2 Vomer Sutures Suture seam or stitch is an immovable joint found only between skull bones Four prominent sutures are 1 2 3 4 Coronal Suture between the frontal bone and the two parietal bones Sagittal Suture between the two parietal bones Lambdoidal suture between the parietal bones and the occipital bone Sguamosal suture between the parietal and the temporal bones CRANIAL BONES a Frontal Bone Forms the forehead the anterior part ofthe cranium the roof the orbits eye sockets and most ofthe anterior part of the cranial floor Left and right parts ofthe frontal bone are united soon after birth by a suture This suture disappears by age 6 Metopic Suture ifthis suture somehow persist throughout life Supraorbital margin a thickening of the frontal bone Parietal Bone form the greatest portion ofthe sides and roof ofthe cranial cavity Temporal Bones a pair form the inferior sides of the cranium and part of cranial floor 1 Petrous Portion of the Temporal Bone contains the internal ear in which are located the structures involved in hearing and equilibrium balance 2 Carotid Foramen canalthrough which the internal carotid artery passes 3 Jugular Foramen fossa through which the internal jugularvein and the glossopharyngeal ix nerve vagus X nerve and accessory xi nene pass 4 Mastoid Portion ofthe Temporal Bone in adult contains mastoid air quotcellsquot 5 Mastoid process serves as a point of attachment for several neck muscles Occipital Bone forms the posterior part and a prominent portion of the base ofthe cranium 1 Foramen Magnum is a large hole in the inferior part ofthe bone through which the medulla oblongata part of the brain and its membranes the spinal portion ofthe accessory xi nerve and the vertebral and spinal arteries pass 2 Occipital Condyles articulate form ajoint with depression on the first cervical vertebra Sphenoid Bone is situated at the middle part ofthe base of the skull Referred to as the keystone of the cranial floor because it articulates with all the other cranial bones Ethmoid Bone is a light spongy bone located in the anterior part of the floor of the cranium between the orbits Is the principal support structure ofthe nasal cavities FACIAL BONES Growth ofthe face ceases at approximately 16 year of age a Nasal Bones are small oblong bones that meet at the middle and superior part ofthe face Are paired Maxillae are paired unite to form the upper 39awbone and articulate with every bone ofthe face except the mandible or lowerjawbone c Paranasal Sinuses not cranial orfacial bones Besides producing mucus lighten the skull bones and serve as resonant chambers for sound as we speak or sing d Zygomatic Bones malars commonly referred to as the cheekbones are paired e Mandible the lowerjawbone Is the largest strongest facial bone It is the only movable skull bone other than the auditory ossicles f Lacrimal Bones are thin bones roughly resembling a fingernail in size and shape Are the smallest bones of the face are paired g Palatine Bones are Lshaped and form the posterior portion of the hard palate two h lnferior Nasal Conchae are scrolllike bone that form a part of the lateral wall of the nasal cavity and project into the nasal cavity inferior to the superior and middle nasal conchae of the ethmoid bone i Vomer is a roughly triangular bone that forms the inferior and posterior part ofthe nasal septum ORBITS Orbit eye socket is a pyramidshaped space that contains the eyeball and associated structures Formed by seven bones ofthe skull Principal Openings of each Orbit 1 Optic Foramen canal at the junction of the roof and medial wall 2 Superior Orbital Fissure at the upper lateral angle of the apex 3 lnferior Orbital Fissure at the junction of the lateral wall and floor 4 Supraorbital Foramen notch on the medial side of the supraorbital margins ofthe frontal bone 5 Canal for Nasolacrimal Duct in the nasal bone FORAMINA Openings or perforations in a bone HYOID BONE Ushaped A unique component of the axial skeleton because it does not articulate with any other bone VERTEBRAL COLUMN Vertebral Columnlspinel Sternum Ribs gt Skeleton ofthe Trunk of the body Vertebral column consists of a series of bones called Vertebrae which makes up about 25 of total height of the body Vertebral Column is a strong flexible rod that moves anteriorly posteriorly and laterally and rotates Functions it encloses and protects the spinal cord supports the head and senes as a point of attachment for the ribs and muscles ofthe back lntenertebral Foramina openings between vertebrae The nerves that connect the spinal cord to various parts of the body pass through these openings Typical Adult Vertebral Column Contains 26 vertebrae 7 Cenical vertebrae cenix neck C1 C7 12 Thoracic vertebrae thorax chest T1 T12 5 Lumbar vertebrae Lumbus loin L1 L5 5 Sacral vertebrae fused in one called Sacrum 4 Coccygeal vertebrae fused into one or two bones called coccyx 9390 Prior to the fusion of the sacral and coccygeal vertebrae the total number of vertebrae is Q lntenertebral Discs found between vertebrae Form strong joints permit various movements of the vertebral column and absorb vertical shock Under compression they flatten broaden and bulge from their intenertebral spaces NORMAL CURVES Convex a 1 Cenical Curve formed by cervical vertebrae 3 Lumbar Curve formed by lumbar vertebrae Called secondary curves are modified of the fetal position Concave 8 2 Thoracic Curve formed by thoracic vertebrae 4 Sacral Curve formed by sacral vertebrae Called Primary Curve retain the anterior concavity of the fetus TYPICAL VERTEBRAE All the vertebrae are basically similar in structure despite variations in size shape and detail 1 Body Centrum thick and discshaped anterior portion is the weight bearing part ofthe vertebra Superior and inferior surfaces are roughened for the attachment of intenertebral discs 2 Vertebral neural Arche Pendicles and Laminae Extends posteriorly from the body of the vertebra Surrounds the spinal cord together with the body of the vertebra The Space that lies between the vertebral arch and body contains the spinal cord Vertebral Foramen is the space between the vertebral arch and the body of the vertebrae ertebral spinal Canal the vertebral foramina of all vertebrae put together 3 Processes seven ofthem arise from the vertebral arch Transverse process 2 Spinous process 1 Superior articular process 2 Inferior articular process 2 Cervical Region Cenical Vertebrae are smaller than those of thoracic vertebrae 01 C7 g The Atlas named for its support of the head It lacks a body and a spinous process Q The Axis have a body A peglike process called the dens dens tooth projects up through the ring of the atlas The dens makes a point on which the atlas and head rotate 0306 Correspond to the structural pattern ofthe typical cervical vertebrae previously described g Called the Vertebra Prominens is somewhat different ls marked by a large nonbifid spinous process that may be seen and felt at the base ofthe neck THORACIC REGION Thoracic Vertebra are considerably larger and stronger than the vertebra of the cervical region T1 T2 Articulate with ribs LUMBAR REGION Lumbar Vertebrae are the largest and strongest in the column L1L5 stomach area SAC RU M AND COCCYX Sacrum Sacred or holy bone is a triangular bone formed by the union of five sacral vertebrae 81 SS Serves as a strong foundation for the pelvic girdle Coccyx is also triangular in shape and is formed by the fusion ofthe coccygeal vertebrae usually the last four 001 004 THORAX Thorax refers to the chest The skeletal portion ofthe thorax is a bony cage formed by the sternum costal cartilage ribs and the bodies ofthe thoracic vertebrae Sternum the breastbone Ribs makes up the sides of the thoracic cavity a 1 7 Ribs True vertebrosternal ribs Attachment to the sternum by a strip of hyalin cartilage called costal cartilage b Remaining 5 pairs of ribs False ribs because their costal cartilage do not attach directly to the sternum The cartilages ofthe 8th 9th and 10th ribs attach to each other and then to the cartilage of the 7th rib These false ribs are called Vertebrochondral ribs The 11th and 12th False ribs are designated as Floating vertebrall because their anterior ends do not attach even directly to the Chapter 9 JOINTS Chapter 9 Anatomy and Physiology Lecture Chapter 9 2 JOINTS Bones are too rigid to bend without causing damage Bones are held together atjoints by flexible connective tissue Imagine how a cast overthe knee prevents flexibility Articulation Joint is a point of contact between bones between cartilage and bone or between teeth and bones Arthrology Scientific study ofjoints The joints structure determines how it functions Somejoints permit no movement others permit slight movement and still others afford considerable movement The looser the fit the greaterthe movement Loosely fitted joints are prone to dislocation CLASSIFICATION OF JOINTS 1 Structural classification 2 Functional classification 1 Structural Classification 1 Fibrous Joints 2 Cartilaginous Joints Chapter 9 3 3 Synovial Joints Structural classification ofjoints are based on a The presence or absence of a synovial joint cavity a space between the articulating bones and b The kind of connective tissue that binds the bones together Structurallyjoints are classified as a Fibrous In which there is nojoint cavity and bones are held together by fibrous connective tissue b Cartilaginous In which there is no joint cavity and the bones are held together by cartilage and c Synovial In which there is a joint cavity and the bones forming the joint are united by a surrounding articular capsule and frequently by accessory ligaments 2 Functional classification Takes into account the degree of movement they permit Joints are classified as A Synarthroses is an immovablejoint B Amphiathroses is a slightly movablejoint C Diarthroses is a freely movablejoint A S narthrosis immovable 39oint Lack a synovial cavity Articulating bones held closely together by fibrous connective tissue Permit little or no movement Threet es of s narthrosis Chapter 9 Suture Gomphosis Synchondrosis Sutures A fibrous joint composed of a thin layer of dense fibrous connective tissue Unites the bones of the skull Found between bones of the m United by a thin layer of dense fibrous connective tissue Irregular interdigitated structure gives them added strength and decreases chances of fractures Functionally classified as Synaithroses are immovable Gomphosis To bolt together A fibrous joint in which a coneshaped pegfits into a socket Found in articulation ofthe roots of the teeth with the alveoli sockets of the Maxillae and mandible Synchondrosis A cartilaginous joint in which the connecting material is hyaline cartilage Joint between the rib and the sternum Epiphyseal plate Is a temporary joint since it is eventually replaced by bone Chapter9 when growth ceases B Amphiarthrosis Slightly Moveable Jointj Do not have Synovial Cavity Like fibrous joints they allow little or no movement Two tyges of Amphiarthrosis Joint 1 Syndesmosis and 2 Symphysis 1 Syndesmosis A fibrous joint in which there is considerably move fibrous connective tissue than in suture Found in the distal articulation of the tibia and fibula 2 Symghysis A cartilaginous joint in which the connecting material is a broad flat disc of fibrocartilage Found between bodies of vertebrae The pubis symphysis between the anterior surface of hip bones C Diarthrosis Freel Movable Joint 1 Structure Chapter 9 6 Synovial Joint is a joint in which there is a space between articulating bones Synovial Joint Cavity is the name ofthat space Articular Cartilage covers the surface of the articulating bones bust does not bind the bones together Articular Capsule encloses the synovial cavity and unites the articulating bones Composed of two layers a Fibrous Capsule is the outer layer Consists of dense connective collagenous tissue The fibers are arranged in parallel bundles and are highly adapted to resist recurrent strain Such fibers are called Ligaments b Synovial Membrane is the inner layer Composed of loose connective tissue with elastic fibers and a variable amount of adipose tissue Secretes Synovial Fluid SF Synovial Fluid lubricates thejoint and provides nourishment for the articular cartilage Synovial fluid is similar in appearance and consistency to uncooked egg white One interesting feature of some synovial joint is their ability to produce a cracking sound when pulled apart Contact and Movement at a Diarthrosis a Structure shape ofthe articulating bones how they fit with respect to each other Chapter 9 7 Tension of ligaments tense ligaments restrict the range of movement Muscle arrangement and tension Apposition of soft parts may limit mobility eg if you bend your arm at the elbow it can move no further as the anterior surface ofthe forearm presses against the arm e Hormones eg Relaxin ao TYPES OF DIARTHROSIS Synovial Joints are classified according to the shape of the adjoining articular surface They are divided into six subtypes a a b c d e f Plane or Gliding Hinge Pivot Ellipsoidal Saddle and BallandSocket Plane or Gliding Joints are usually flat Only sidetoside and backandforth movements are permitted Twisting and rotation are inhibited at gliding joints generally because ligaments or adjacent bones restrict the range of movement Gliding joints are referred to as Nonaxial because it does not move around an axis Example Joints between carpal bones tarsal bones the sternum and clavicle and the scapula and clavicle Hinge or Ginglymus Joint is one in which the convex surface of one bone fits into the concave surface of another bone Chapter 9 8 Movement is usually Flexion and Extension Motion is similar to that of a hinged door Movement is primarily in a single plane and thejoint is therefore known as Monoaxial or Uniaxial Flexion decreases the angle between articulating bone Extension increases the angle between articulating bones often to restore a body part to its anatomical position after it has been flexed Hyperextension continuation of extension beyond the anatomical position such as when the head bends backward Pivot or Trochoid Joint a rounded pointed or conical surface of one bone articulates within a ring formed partly by another bone and partly by a ligament The primary movement permitted is rotation and thejoint is therefore Monoaxial Joint between the atlas and axis atlantoaxial Joint between the proximal ends of the radius and ulna Example Supination and Pronation of the palms and rotation of the head from side to side Ellipsoidal or Condyloid Joint an ovalshaped condyle of one bone fits into an elliptical cavity of another bone Since the joint permits sidetoside and backandforth movements it is Biaxial Joint at the wrist between the radius and carpals when you flex and extend and abduct and adduct and circumduct the wrist Example Saddle or Sellaris Joint the articular surface of one bone is Chapter 9 9 saddleshaped and the articular surface ofthe other bone is shaped like a rider sitting in the saddle Movement at a saddle joint are side to side and back and forth thus thejoint is Biaxial Joint between the trapezium of the carpus and metacarpal of the thumb Example BallandSocket or Sbheroid Joint consists of a balllike surface of one bone fitted into a cuplike depression of another bone Such a joint permits Triaxial movement or movement of three planes of motion Flexionextension abductionadduction and rotationcircumduction Example Shoulderjoint and Coxal hipjoint Types of Movements A Gliding Movement Is the simplest kind that can occur at ajoint One surface moves back and forth and from side to side over another surface without angular or rotary motion Examples Joints between carpals and between tarsals B Angular Movement Increases or decreases the angle between bones Examples are i Flexion Involves a decrease in the angle between the surfaces ofthe articulating bones Examples Bending the head fonvard thejoint is between the occipital bone and the atlas bending the elbow and bending the knee Chapter 9 il iii W 10 Extension Involves an increase in the angle between the surfaces ofthe articulating bones Restores a body to its anatomical position after it has been flexed Examples Head to anatomical position Straightening the arm after flexion straightening the leg after flexion Hyperextension continuation of extension beyond the anatomical position Example Bending the head backward Abduction Usually means movement of a bone away from the midline ofthe body Moving the arm upward and away from the body until it is held straight out at right angles to the chest Example Adduction ls usually movement of a part toward the midline ofthe body Example Returning the arm to the side after abduction C Circular Movement Involves the rotation of a structure around an axis or movement of the structure in an arc i ii iii Rotation Is the turning of a structure around its long axis Example Rotation of the head the humerus or the entire body Pronation ls rotation of the forearm so that the palm faces posteriorly in the relation to the anatomic position Supination ls rotation of the forearm so that the palm faces Chapter 9 iV anteriorly in relation to the anatomic position Circumduction Is a combination of fleion extension abduction and adduction It involves a 360 rotation Moving the outstretched arm in a circle to wind up to pitch a ball Example D Special Movements Movements that are unique to only one or two joints that do not fit neatly into one of the other categories Vi Inversion is the movement of the sole of the foot inward medially so that the soles face toward each other Eversion is the movement of the sole outward laterally so that the soles face away from each other Dorsiflexion involves bending of the foot in the direction ofthe dorsum upper surface Planter Flexion involves bending the foot in the direction ofthe planter surface sole Protraction is the movement of the mandible or shoulder girdle fonvard on a plane parallel to the ground Thrusting the jaw outward is protraction of the mandible Bringing your arms fonvard until the elbows touch requires protraction ofthe clavicle or shoulder girdle Example Retraction is the movement of a protracted part of the body backward on a plane parallel to the ground Example Pulling the lowerjaw back in line with the upperjaw Chapter 9 vii viii v M X is retraction of the mandible Supination is a movement of the forearm in which the palm of the hand is turned anterior or superior facing up Flexing of forearm at the elbow to prevent rotation ofthe humerus in the shoulderjoint Example Pronation is a movement ofthe forearm in which the palm is turned posterior or inferior facing down Elevation is an upward movement of a part of the body You elevate your mandible when your close your mouth Example Depression is a downward movement of a part ofthe body You depress your mandible when you open your mouth Example Shoulders can also be elevated and depressed E Knee Tibiofemoral Joint Structure of knee joint illustrates the complexity of a diarthrosis Knee Tibiofemoral 39oint is the largestjoint ofthe body Anatomical Components of the Knee Joints 1 Articular Capsule 2 Medial and Lateral Patellar Retinacula 3 Patellar Ligament Chapter9 13 Oblique Popliteal Ligament Arcuate Popliteal Ligament Tibial Medial Collateral Ligament Fibular Lateral Collateral Ligament lntraArtioular Ligament a Anterior Cruciate Ligament ACL b Posterior Cruciate Ligament PCL 9 Articular Discs a Medial Meniscus b Lateral Meniscus 10 Bursae a Anterior Bursae b Medial Bursae 0 Lateral Bursae 00 me SUMMARY OF JOINTS Synarthrosis lmmovable Joints 1 Suture 2 Synohondrosis 3 Gomphosis Amphiarthroses slightly movable joints 1 Syndesmosis 2 Symphysis Diarthroses freely movable joints 1 Gliding 2 Hinge Pivot Ellipsoidal Saddle BallandSooket monspo Chapter 5 THE INTEGUMENTARY SYSTEM Chapter 5 Anatomy and Physiology Lecture Chapter 5 2 THE INTEGUMENTARY SYSTEM Integumentary System Consists of the w and accessory structures such as nails and glands Integument means covering Overview of the Integumentary System Maior Functions of the Integumentary System Protection Sensation Temperature regulation Vitamin D production Excretion 9390 HYPODERMIS Hypodermis Attaches the skin to the underlying bone and muscles and supplies it with blood vessels and nerves Main types of cells within the hypodermis are fibroblast adipose cells and macrophages Subcutatneous tissue of Superficial fascia Hypodermis that is not part of the skin SKIN Skin is one ofthe largest organs of the body in terms of surface area and weight Dermatology is the medical specialty that deals with the diagnosis and treatment of skin disorders Chapter5 3 Two Ma39or Tissue Layers of Skin a Epidermis The outer thinner portion composed of stratified squamous epithelium epithelium Lack blood vessels lymphatic vessels and connective tissue b Dermis The inner thicker portion composed of connective tissue DERMIS Dermis is the second principal part of the skin composed of connective tissue containing collagenous and elastic fibers Collagen a protein the main organic constituent of connective tissue a Papillary Region or Layer Upper region of the dermis Consists of loose areolar connective tissue containing fine elastic fibers ts surface area is greatly increased by small fingerlike projections called Dermal Papillae Dermal Papillae project into the epidermis and may contain loops of capillaries Some dermal papillae also contain corpuscles of touch also called Meissner39s Corpuscles nerve endings that are sensitive to touch b Reticular Region or Layer Remaining portion ofthe Dermis Consists of dense irregularly arranged connective tissue containing interlacing bundles of collagenous and coarse elastic fibers Combination of collagenous and elastic fibers in the reticular region Chapter5 4 provides the skin with strength extensibility and elasticity Extensibility is the ability stretch Elasticity is the ability to return to original shape after extension or contraction Ability of the skin to stretch can readily be seen during conditions of pregnancy obesity and edema The small tears that occur during extreme stretching are initially red and remain visible aftenvard as silvery white streaks called striae Reticular region is attached to underlying organs such as bone and muscle by the subcutaneous layer also called Hypodermis or superficial fascia Subcutaneous Layer also contains nene ending called Lamellated or Pacinian Corpuscles that are sensitive to pressure EPIDERMIS ls composed of stratified squamous epithelium and consists M distincttypes of cells 1Keratinocytes 2 Melanocytes 3 Langerhans and 4 Merkel cell 1 Keratinocyte Is the most numerous type of epidermis and undergoes keratinization Production of the Protein Keratin which helps waterproof and protect the skin and underlying tissues Participate in immunity 2 Melanocyte A second type of cell in the Epidermis Chapter5 5 Located at the base of the epidermis Produces melanin one of the pigments responsible for skin color and the absorption of ultraviolet UV light 3 Langerhans39 Cell Nonpigmented granular dendrocytes Are a small population of dendrocytes that arise from bone marrow and migrate to the epidermis and other areas ofthe body that contain stratified squamous epithelial tissue Are sensitive to UV radiation nteract with cells called Helpe T Cells to assist in the immune response 4 Merkel Cell located in the deepest layer stratum basale Makes contact with flattened portion ofthe ending of a sensory neuron nerve cell called a Tactile Merkel Disc Five La ers Strata of E idermis From the Dee est to The Most Superficial a Stratum Basale the deepest of the Epidermis Stratum Basale is sometimes referred to as the stratum germination to indicate its role in germinating new cells Is a single layer of cuboidal to columnar cells capable of continued cell division Stratum basale of hairless skin contains nerve endings sensitive to touch called Tactile Merkel39sl discs b Stratum Spinosum Contains 8 to 10 layers of polyhedral manysided cells that fit closely together The surfaces contain spinelike projections that join the cells Chapter 5 together Stratum Granulosum Consists ofthree to M row of flattened cells contain darkly staining granules of a substance called Keratohyalin involved in the first step of Keratin formation Consists of substance called keratohyalin Keratin is a water proofing protein found in the top layer of the epidermis Stratum Lucidum Normally found only in the thick skin ofthe palms and soles and is absent in thin skin Consists of three to M rows of clear flat dead cells that contain droplets of a substance called eleidin Eleidin is translucent formed from keratohyalin and is eventually transformed to keratin Stratum Corneum the outermost layer Consists ofg to layers of flat dead cells completely filled with keratin Are continuously shed and replaced Serves as an effective barrier against light and heat waves bacteria and many chemicals In the process of Keratinization newly formed cells produced in the basal layers are pushed up to more superficial layers gidermal Growth Factor EGFl is a protein hormone that functions as a growth factor ChapterS 7 THICK AND THIN SKIN Thick Skin Has all five epithelial strata and the stratum cornuem has many layers of cells Found in areas subject to pressure or friction such as palm ofthe hands the soles of the feet and the fingertips Thin Skin Covers the rest of the body and is more flexible than thick skin SKIN COLOR Color of Skin is due to i Melanin a pigment in the epidermis ii Carotene a pigment mostly in the dermis and iii Blood in capillaries in the dermis Melanin is synthesized in cells called Melanocytes Melanocytes are produced from Melanoblasts Are most plentiful in the mucous membranes penis nipples of the breasts and the areajust around the nipples areola face and extremities Melanin gives color to the skin Varies skin color from pale yellow to black The amount of Melanin black pigment accounts for the color differences among the races Since the number of melanocytes is about the same in all races differences in skin color are due to the amount of pidment the melanocytes produce and disperse That is individuals with darker skin possess more active melanocytes not Chapter 5 8 a greater number of melanocytes The presence of Melanin in the epidermis is vital for protection against the harmful effects of Ultraviolet Radiation which can manifest themselves as skin cancer Albinism an inherited inability of an individual of any race to produce melanin Albino an individual affected with albinism Vitiligo the partial or complete loss of melanocytes from areas of skin producing patchy white spots In some people melanin tends to form in patches called freckles Carotene a pigment found in the stratum corneum of epidermis and fatty areas ofthe dermis in people of Asian origin Carotene and Melanin together account forthe yellowish hue oftheir skin Pink color of Caucasian skin is due to blood in capillaries in the dermis The redness ofthe vessels is not heavily masked by pigment The Egidermis has no blood vessels a characteristic of all Epithelia Heimoglobin pigment that carries oxygen in blood gives blood its red co or Clinical Application Malignant Melanoma Caused by overexposure of the skin to the ultraviolet light ofthe sun leading to skin cancer Chapter 5 9 EPIDERMAL RIDGES AND GROOVES The outer surface ofthe skin of the palms and ngers and soles and toes is marked by a series of ridges and grooves that appear either as fairly straight lines or as a pattern of loops and whorls as on the tips ofthe digits Epidermal Ridges Develop during the third and fourth fetal months as the epidermis conforms to the contours ofthe underlying dermal papillae The function of the ridges is to increase the grip of the hand or foot by increasing friction and acting like tiny suction cups Since the ducts of sweat glands open on the summits of the epidermal ridges as sweat pores fingerprints or footprints are left when a smooth object is touched The sweat helps form fingerprints or footprints when smooth object is touched The ridge pattern is genetically determined and is unique for each individual and does not change throughout life except to enlarge Serves as the basis for identi cation through fingerprints or footprints ACCESSORY SKIN STRUCTURES Are structures developed from the embryonic epidermis eg Hair skin glands sebaceous sudoriferous and ceruminous and nails 1 Hair Are epidermal growth that function in protection Consist of a shaft above the surface root that penetrates the dermis and subcutaneous layer and a hair follicle Associated with hairs are sebaceous oil glands arrectores pullorum muscles and hair root plexuses Chapter5 10 New hair develop from cell division of the matrix in the bulb hair replacement and growth occur in a cyclic pattern quotMalepatternquot baldness is caused by androgens and heredity Color of hair is due primarily to melanin Primary function is protection Protect scalp from injury From sun rays Decrease heat loss Eye from foreign particles In nostrils n ears Electrolysis the hair bulb is destroyed by an electric current so that the hair cannot regrow 2 Glands i Sebaceous Oil Glands are usually connected to hair follicles they are absent in the palm and soles Produce sebum which moistens hairs and waterproofs the skin Enlarged sebaceous glands may produce blackheads pimples and boils ii Sudoriferous Sweat Glands are divided into apocrine and eccrine a Apocrine Sweat Glands are limited in distribution to the skin of the axilla pubis and areolae their ducts open into hair follicles b Eccrine Sweat Glands have an extensive distribution Produce perspiration which carries small amounts of wastes to the surface thereby Assists in maintaining body temperature Their ducts terminate at pores at the surface ofthe epidermis Chapter 5 11 iii Ceruminous Glands are modified sudoriferous glands that secrete cerumen Are found in the external auditory meatus Nails Nails are hard keratinized epidermal cells over the dorsal surfaces ofthe terminal portions of the fingers and toes The principal parts of a nail are the My free edge Lot lunula eponychium lcuticlel and matrix Cell division ofthe matrix cells produces new nails Functionally nails help us to grasp and manipulate small objects in various ways and provide protection against trauma to the ends of the digits THERMOREGULATION HOMEOSTASIS OF BODY TEMPERATURE One of the functions ofthe skin is the maintenance of a normal body temperature 3720 986Fl If environmental temperature is high skin receptors sense the stimulus heat and generate impulses that are transmitted to the brain The brain then causes the sweat glands to produce perspiration As the perspiration evaporates the skin is cooled The skincooling response is a negative feedback mechanism Temperature maintenance is also accomplished by adjusting blood flow to the skin regulating metabolic rate and regulating skeletal muscle contractions Chapter5 12 AGING AND THE INTEGUMENTARY SYSTEM 1 Most effects of aging occur when an individual reaches the late forties 2 Among the effects of aging are wrinkling loss of subcutaneous fat atrophy of sebaceous glands and decrease in the number of melanocytes DEVELOPMENTAL ANATOMY OF THE INTEGUMENTARY SYSTEM 1 The epidermis is derived from ectoderm Hair nails and skin glands are epidermal derivatives 2 The dermis is derived from wandering mesodermal cells DISORDERS HOMEOSTATIC IMBALANCES 1 Acne is an inflammation of sebaceous oil glands and usually begins at puberty 2 Systemic lupus erythematosus SLE is an autoimmune inflammatory disease of connective tissue 3 Psoriasis is a chronic skin disease characterized by reddish raised plaques or papules 4 Decubitus ulcers are caused by a chronic deficiency of blood to tissue subjected to prolonged pressure or bedsores or pressure sores 5 Sunburn is a skin injury resulting from prolonged exposure to the UV rays of sunlight Chapter 1 1 AN INTRODUCTION TO THE HUMAN BODY Chapter 1 Anatomy and Physiology Lecture Chapter 1 2 AN INTRODUCTION TO THE HUMAN BODY Why Study Anatomy and Physiology 1 Knowledge of the Structure and Function of the human body provides the basis for understanding disease Knowledge of the Structure and Function of the human body is essential for those planning a career in the health sciences Knowledge of the Structure and Function of the human body is beneficial to nonprofessional because it helps with understanding overall health and disease with evaluating recommended treatment and with critically reviewing advertisements and articles Anatomy and Physiology are two branches of science that will help us understand our body parts and their functions Anatomy Is the scientific discipline that investigates the body s structure LEVELS OF ANATOMY 1 Developmental Anatomy Is the study of the structural changes that occur between conception and adulthood 2 Embryology Is a subspecialty of developmental anatomy considers changes from conception to the end of the eighth week of development 3 Cytology Examines the structural features of cells 4 Histology Examines the tissues which are cells and the materials surrounding them 5 Gross Macroscopic Anatomy Is the study of structures that can be examined without the aid of a microscope can be approached from either a systemic or regional perspective Chapter 1 3 6 Systemic Anatomy Is the study of specific systems of the body such as the nervous system respiratory system etc 7 Regional Anatomy Is the study of a specific region ofthe body such as the head the chest abdomen arm etc 8 Surface Anatomy Is the study of the external form of the body and its relationship to deeper structures 9 Anatomic imaging Uses radiographs xrays ultrasound magnetic resonance imaging MRI and othertechnologies to create pictures of internal structures Physiology Physiology Is the scientific investigation of the processes or functions of living things 1 2 Cell Physiology Examines the processes occurring in cells Systems Physiology Considers the functions of organs systems Pathophysiology study of functional changes associated with disease and aging Neurophysiology Focuses on the nervous system Cardiovascular Physiology study of functions of the heart and blood vessels Pathology Is the medical science dealing with all aspects of disease with an emphasis on the cause and development of abnormal conditions as well as the structural changes resulting from disease 7 Exercise Physiology Focuses on changes in function but also structure caused by exercise Chaper 4 LEVELS OF STRUCTURAL ORGANIZATION Fig 11 page 3 Several levels of structural organization that associated with one another in various ways A CHEMICAL LEVEL the lowest level of organization Contains atoms such as Carbon C hydrogen H oxygen 0 Nitrogen N Calcium Ca Potassium K and Sodium Na 1 Atoms smallest unit of matter anything that occupies space and has mass 2 Molecules combination of two or more atoms eg proteins carbohydrates fats and vitamins CELLULAR LEVEL 1 Cells Are the basic structural and functional units of all living things 2 Organelles Formed by the combination of molecules Are the small structures that make up cells TISSUE LEVEL 1 Tissue ls group of similar cells and the substances surrounding them Four Basic Types of Tissue in the human body a Epithelial Tissue LinesCovers Functions Absorption eg the lining of the small intestine Transport eg kidney tubules Excretion eg sweat gland Protection eg the skin Sensor reception eg the taste buds in the tongue Chapterl 5 Classified on the basis of shape and number of layers On Layers Simple epithelium only one layer of cell Stratified epithelium two or more layers stacked on top of the other On Shapes Squamous epithelium flat Cuboidal epithelium cube shaped Columnar epithelium column like b Connective Tissue Connection and support Adipose Cartilage Bone Blood c Muscle Tissue Movement d Nervous Tissue Communication Each type of cell in the tissue has a specific function D ORGAN LEVEL Organ ls composed of m or more tissues types that perform one or more common functions For example Heart Liver Lungs Brain Stomach E ORGAN SYSTEM LEVEL Organ System Is a group of organs that have a common function or set of functions and are therefore viewed as a unit For example Urinary system Digestive system Respiratory system Reproductive system lntegumentary system Skeletal system Chapter 1 6 F Muscular system Nervous system Cardiovascular system etc ORNISMISM LEVEL The highest level Organism Is any living thing considered as a whole whether composed of one cell such as a bacterium ortrillions of cells such as human CHARACTERISTICS OF THE LVING HUMAN ORGANISM Characteristics of Life Humans are organism and share common characteristics with other organisms Life is the most important common feature of all organisms Six Life s Essential Characteristics 1 Organization Is the condition in which the parts of an organism have specific relationship to each other and the parts interact to perform specific function Metabolism Is all ofthe chemical reactions taking place in an organism Responsiveness Is the ability of an organism to sense changes in its external or internal environment and adjust to those changes Growth Happens when cells increase in size or number which produces an overall enlargement of all or part of an organism Development Changes an organism undergoes through time it begins with fertilization and ends at death Involves Growth Differentiation and Morphogenesis Differentiation ls changes in cell structure and function from Chapterl 7 generalized to specialized Morphogenesis ls changes in shape oftissues organs and the entire organism 6 Reproduction Is the formation of new cells or new organisms CONTROL OF HOMEOSTASIS Homeostasis Is the existence and maintenance of a relatively constant environment within the body Cells need relatively stable conditions fluids surrounding the cell to function effectively and contribute to the survival of the body as a whole Variable Condition For cell to function normally the volume temperature and chemical content of the body fluid must remain within a narrow margin Set Point The ideal normal value Normal range Slightly around the set point values Note lfthe cell fluid surrounding cells deviate from homeostasis the do not function normally and can die Disruption of homeostasis results in disease and sometimes death NegativeFeedback Negative means that any deviation from the set point is made smaller or is resisted Note Most feedback systems in the body are negative Chapter 1 8 Three Basic Components of a Negative Feedback Mechanism 1 Control center 2 Receptor 3 Effector 1 Control Center determines the point at which some aspect ofthe body called controlled condition should be maintained Control center receives information about the status of a controlled condition from a receptor and then determines an appropriate course of action Hundred of Controlled Conditions exist in the body Heart rate blood pressure acidity of the blood blood sugar level body temperature breathing rate etc 2 Receptor monitors changes in the controlled condition and then sends the information called inputs to the control center Stimulus is any stress that changes a controlled condition Example A stimulus such as exercise raise the body temperature the controlled condition and thermal heat receptors send input to the control center which in this case is in the brain 3 Effector receives information called the output from the control center and produces a response effect So while you are exercising your brain control center signals for increased secretions by your sweat glands effectors as sweat evaporates from the skin body temperature drops back to normal The response that occurs is continually monitored by the receptor and feed back to the control center Note The maintenance of normal blood pressure is an example of a Chapterl 9 negativefeedback mechanism that maintains homeostasis PositiveFeed back Positivefeedback responses are not homeostatic and are rare in healthy individuals Positive lmplies that when a deviation from the normal value occurs the response of the system is to make the deviation even greater Note Positivefeedback usually creates a cycle that leads away from homeostasis and in some cases results to death Some Good Examples of NegativeFeedback Blood clotting which helps stop loss of blood from a cut Labor contractions during birth of a baby ANATOMICAL TERMINOLOGY BODY POSITIONS ln anatomy descriptions of any region or part of the human body assume that the body is in a specific position anatomical position Anatomic Position Four characteristics ofthe anatomical position 1 the subject stands erect upright position facing the observer 2 with feet flat on the floor 3 arms placed at the sides and 4 the palms of the hand turned fonvard Having one standard anatomical position allows directional terms to be clear any part or region can be described relative to any other part Note Know the common names and anatomical terms in parentheses Chapter 1 10 REGIONAL NAMES Regional names are terms given to specific region of the body for reference Examples Cranial skull thoracic chest brachial arm patellar knee cephalic head and gluteal buttock DIRECTIONAL TERMS Direction terms indicate the relationship of one part of the body to another Like regional names used for uniformity all over the world PLANES AND SECTIONS Planes are imaginary flat surfaces that are used to divide the body or organs into definite areas 1 Sagittal Plane is a vertical plane that divides the body or an organ into right and left sides 2 Midsagittal median Plane is a vertical plane that passes through the midline ofthe body or organs and divides it into equal right and left sides 3 Parasgittal Plane is a sagittal plane that does not pass through the midline but instead divides the body or an organ into unequal right Chapterl 11 and left sides 4 Frontal coronal Plane divides the body or organ into anterior front and posterior back portions 5 Transverse crosssectional or Horizontal Plane divides the body or organ superior top or inferior bottom portions Above planes are all at right angles to one another 6 Obligue Plane passes through the body or organ at an angle between the transverse plane and either the midsagittal parasgittal or format plane BODY CAVITIES Body Cavities are confined spaces within the body that contain internal organs Cavities separated from each other by structure such as muscles bones or ligaments helpto protect separate and supportthe organs Two Principal Body Cavities 1 Dorsal body cavity 2 Ventral body cavity 1 Dorsal Body Cavity is located near the dorsal back surface ofthe body Two principal subdivisions of Dorsal Bodv Cavitv a Cranial Cavity formed by the cranial skull bones and containing the brain b Vertebral spinal canal formed by the vertebrae of the backbone Chapterl 12 and contains the spinal cord and the beginnings roots of spinal nerves 2 Ventral Body Cavity is located on the ventral front aspect of the body Serous membrane a thin slippery tissue lines the wall of the ventral body cavity and covers the organs within it Viscera are organs inside the ventral body cavity Two Principal Subdivisions of the Ventral Body Cavity A Thoracic Cavity Chest Cavity an upper portion Thoracic Cavity has three compartments 1 Two Pleural cavities each of the two surrounds a lung M is the serous membrane associated with the lungs 2 Pericardial Cavity between the lungs Pericardium is the serous membrane associated with the heart Mediastinum is a region between the lungs extending from the sternum breastbone to the vertebral column or backbone Diaphragm is the structure anatomical landmark that divides the ventral body cavity into the thoracic and abdominopelvic cavities B Abdominopelvic Cavity the lower portion of ventral body cavity As the name suggests is divided into two portions although no wall separates themabdominal and pelvic cavities Peritoneum is the serous membrane that lines the abdominopelvic cavity and covers the organs within


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