Lecture 9 objectives
1. Describe the role of the bone in the body
Protection and storage bone marrow that produces red and white blood cells, Storage of minerals and lipids especially mineral salt, particularly calcium phosphates, deposited in lamellae (rings) around osteocytes, blood cell production, Supporting connective tissue with a solid matrix
2. Describe the types of cells, fibers, and ground substance comprising bone, and recognize the most common arrangement of bone in the body
Osteoblast bone stem cells Osteocytes mature bone cells Osteoclast chew up bone Ground substance Proteoglycans and glycoproteins, 65% hydroxyapatite crystals (mineral salt, particularly calcium phosphates, deposited in lamellae (rings) around osteocytes). Epiphysis at each end, Diaphysis = shaft
Bone surface is covered by periosteum on outside (CT proper “around bone”), and endosteum inside
Articular cartilage at joint surface (hyaline type) at joint surface Don't forget about the age old question of What happened in nat turner’s rebellion?
Compact bone basic unit is osteon which is a concentric rings of bone material around a central canal, each contain several concentric rings of osteocytes organized around a vein, a, artery, and a nerve, separated by lamellae (extracellular matrix). Each ring lies in a small pool of fluid called the lacuna, small branching channel called canaliculi allowing for contact with other cells.
Spongy bone within trabeculae, small interconnected spike of bone, osteocytes are arranged circumferentially, but surrounded by marrow fluid from which the receive nutrients. Makes bone lighter with out giving up strength.
3. Describe the process by which bone is formed and repairs after injury
Endochondral ossification the formation of bone on a cartilage model; cartilage is gradually replaced by bone over years long bone. Shaft pushes out, not growth from the ends. Epiphyseal plate hyaline cartilage grows on one and end and is replaced by bone on the other. Articular cartilage at joint end, never replaced by bone but wears with age, osteoarthritis (old age). Epiphyseal line where the growth plate closes, visible in children, disappears by adulthood. We also discuss several other topics like What is the meaning of the group selection?
Intramembranous ossification formation of new bone with in fibrous membranes, no cartilage template. Formed from mesenchymal generic stem cell Flat bone
Appositional Bone growth The formation of new bone growth along existing bone surface, occurs even after growth plate is closed adult bone remodeling
Factors regulating bone growth hormones, calcium regulation, vitamin D, weight bearing exercise.
Bone heals well bc so highly vascular. Periosteum is important in bone repair after a break because it is the origin site of osteoblast (bone stem cells) the will inate repair. Internal callus > bony callus > healed fracture.Don't forget about the age old question of What is the meaning of biotic?
Lecture 8 objectives
1. Describe the common characteristics of all connective tissue and their roles in the body
Creating structural framework, protecting delicate organs, storing energy reserves, defending the body from microorganisms, defending the body from microorganisms, transport fluids and dissolve materials (blood and lymph). Extracellular Matrix space between cells; contains fiber which provide support, ground substance which fills in all space between cells and fibers determines the consent of the connective tissue If you want to learn more check out What are the characteristics of modern business environment?
2. Describe the types of cells, fibers, and ground substance comprising connective tissue proper and recognize the most common arrangements of CT proper in the body
Found everywhere in the body. Predominant cell type is Fibroblast. Ground substance dense syrup consistency: contains a large amount of sugar and proteins which binds to a large amount of water. Connective tissue proper is arranged into sheets call Fascia
Fibroblasts the primary cell types; produce fibers and most components of ground substance Mesenchymal cells stem cells
Adipocytes fat cells
Melanocytes produce and store melanin pigment
Mast cells histamine containing cells involved in inflammation
Lymphocytes Disease fighting white blood cells
Elastic stretch and recoil
Reticular fine networks
Loose connective tissue proper Allows for migrating cells, blood vessels, nerves lots of ground substance Loose areolar, Adipose tissue Don't forget about the age old question of How we would like the world to be?
Dense connective tissue proper dense packing of collagen makes for stronger tissue Lots of fiber
Dense Irregular connective tissue Fibers are not arranged in a regular order, strong form all different directions
Dense regular connective tissue Fibers are arranged in a regular order, running parallel to each other, strong at certain angles
3. Describe the types of cells, fiber, and ground substance comprising cartilage and recognizing the most common forms of cartilage in the body
Small thin plates of solid material. Chondrocytes located in lacunae (small fluid filled space within the cartilage plate) (chondroblasts immature form). Mostly collagen or elastin. Ground substance is a firm gel containing chondroitin sulfate. Perichondrium (CT proper) separates cartilage from surrounding tissue, contains chondroblast. Avascular no blood vessels, does not heal well.
Hyaline MOST COMMON FORM IN THE BODY. Firm yet, amorphous. Ex. end of long bones, trachea
Elastic similar to hyaline but with more elastic fibers in matrix, great flexibility ex. inner ear Fibrocartilage similar to hyaline but less firm, thick collagen fibers, little ground substance, absorb compression and shock ex. Discs of knee joint, intervertebral discs
4. Explain why some kinds of connective tissue can repair throughout life while others have limited ability to repair We also discuss several other topics like What are the steps in applying scientific method?
Appositional growth add from the edges, chondroblasts in perichondrium produce new cartilage along the surface of the mature cartilage.
Interstitial growth mature chondrocytes divide with their lacunae.
Cartilage exist only in thins sheets because it relies on diffusion to get nutrients. There are limitations to repair because it is avascular and heals poorly when injured due to a lack of blood flow.
Lecture 7 Objectives
1. Describe the characteristics of epithelial sheets
1) Little space between cells, held tightly together by celltocell junctions, Avascular, no blood vessels between cells, limited in thickness bc nutrients are received via diffusion, Specialized for absorption and protection Lateral interdigitations adjacent cells intertwin membranes. 2) Continuous rate of cell division, epithelial stem cells, 90% on cancer occur in epithelial cells bc increase cell turnover mean increase chance of mutation. 3) Cells are polarized, one side is different from the other Apical exposed surface (away from blood supply). Basal surface anchored to connective tissue (toward blood supply) . Basement membrane, including basal lamina, glue like, porous, connects cells to connective tissue 4) specializations Microvilli, small finger like projections of the apical or basal surface increase surface area, covered with transport proteins Active transport CIlia Longer than microvilli but fewer of them, core of microtubules, rhythmical movement meant to transport muscue
2. Name epithelioid sheets by thickness and cell shape and explain the advantages and disadvantages of the different arrangements
Simple one layer thick Stratified more than one cell thick Squamous flat, broad Cuboidal Cubeshape Columnar Tall, narrow cells *Always label by cells on apical surface* SImple Simple squamous Diffusion and filtration, passive transport, protection is not important Simple Cuboidal Secretion and absorption, More cytoplasm, more volume, more mitochondria Active transport Simple Columnar Secretion and absorption, EVEN More cytoplasm, EVEN more volume, EVEN more mitochondria MORE Active transport Stratified squamous Protects underlying tissue, bad for transport, barrier function. Transitional Epithelium within the urethra and bladder, stretches to allow for the storage urine Ciliated Pseudostratified Columnar single layer of cells with varying heights, respiratory system
3. Explain the difference between endocrine and exocrine glands & 4. Explain the main mechanism by which gland cells release their secretions
Endocrine glands release hormones into surrounding fluid to be picked up and transported by the blood stream
Exocrine glands secrete through ducts onto surface of the organ
Merocrine Product release through exocytosis
Holocrine destroy the cells (not program cell suicide, more of a sacrifice)
Unicellular single secretory cell embedded with an epithelium
Lecture 6 objectives
1. Define the term tissue and list the 4 tissue types in the body
Tissues are the collection of specialized cells and cell products organized to perform one or more select functions. Four tissue types: Epithelial, connective, nervous, muscular.
2. Explain the different kinds of cellcell junctions and what advantages each provides to a group of cells
Tight junctions interlocking proteins on the plasma membranes fused cells together preventing molecules from passing through the intercellular space. Separates compartments by sheets of semi permeable tissue; regulates permeability between two compartments. Absorption transport of material toward the bloodstream. Secretion transport of material away from the blood stream.
Desmosomes Anchoring/linker proteins extend across extracellular space and attach to each other. Holds/anchors cells together
Gap junction Membrane proteins from pore between cells allowing a continuous flow of cytoplasm and ions from one cell to another *important in electrical signaling and organs where cells work in close synchrony*.
Functional syncytium a network of small cell functioning as a well coordinated group
3. Compare and contrast the 4 primary modes of cellcell communication.
Direct communication one cell passes signal molecules directly into cytoplasm through gap junctions
Synaptic communication a neuron releases a chemical signal onto the membrane of a target cell long distance
Paracrine communication (local) a chemical signal diffuses a short distance through the extracellular fluid to neighbouring cells short distance
Endocrine communication a chemicals signal is picked up by the blood stream and transport to distant cells Hormone is a chemical message carried by blood stream long distance
*Hormones/chemical message do no “seek out” receptors, rather are released and only accepted by those cells with the proper receptor*
Lecture 5 objectives
1. Name the stages of the cell cycle and describe the events in each stage
Interphase (whole cell) G1: growth in size, synthesis of proteins and RNA for maintenance activities, synthesis of Proteins needed for S phase, duplication of Organelles variable in length of stage S: 6 hours, growth and DNA synthesis, Replication of DNA each of the 46 chromosome is duplicated into sister chromatid via DNA polymerase G2: growth and final preparations for division 4 hours
Mitosis (Events in nucleus)
Prophase: Chromatin condenses into chromosomes, each with two sister chromatids joined at region called centromere Centrioles: organize microtubules, move in opposite directions Microtubules: network assembles into mitotic spindle, nuclear membrane dissolves in a late prophase
Metaphase: Chromatids align at the center of mitotic spindle Metaphase plate Anaphase: microtubules pull chromatids to opposite ends the cell, sister chromatids pulled apart, keeping them together ensure FULL copy is created
Telophase: Microtubule spindle dissociates, nuclear membrane reforms, chromatids disperse to chromatin ready to make proteins
The cytoplasmic event overlapping the end of mitosis Actin network pulls membrane into cleavage furrow separate cytoplasm into two new
2. Explain how the cell cycle is regulated and how this process is altered in cancer
There are a number of checkpoints which regulate the cell cycle. G1 checkpoint phase ensures cell size is adequate, nutrient are available, growth factors are present are G2 checkpoint makes sure cell size is adequate, and chromosome replication is complete Metaphase checkpoint ensures all chromosome are attached at mitotic spindle Protooncogenes Genes whose normal protein products stimulate the cell cycle
Oncogenes Mutated versions of these genes lead to deregulate cell cycle and abnormal growth (cancers)
Tumor Suppressor Genes Genes whose normal protein products repress cell division mutated versions unable to regulate growth (cancers)
Note the difference in the causes of cancer something happening vs failure to repress
Abnormal cells typically die via cell suicide or apoptosis. Other causes of death are Autophagy (self digestion) caused by starvation and Lysis which is caused by a physical trauma.
3. Understand the mechanisms of metastasis
Metastasis is a process which malignant, or invasive tumor cells, spread to other parts of the body. These cells have a lower need for growth factors from surrounding cells so they don't age or die. They secrete proteins that digest extracellular material and signal blood vessels to grow into tumor and nourish (angiogenesis)
4. Describe the role of the stem cells in the human tissue
Partially differentiated Stem cells replace most cells i.e bone marrow, muscle etc. Stem cells are adult cells that are not fully functional/differentiated allowing for cell replacement.
Lecture 4 learning objectives
1. Describe the structure of a gene
A small segment of a chromosome wound around a histone protein that codes for a unique protein. The nucleotide sequence of the gene codes for a particular sequence of amino acids which will bend and fold into a unique protein.
2. Describe the sequence of event in the process of transcription of a gene and how it may be regulated
RNA polymerase binds to the promoter region (start point) of the DNA, splits apart the double helix and begins mRNA synthesis. This step is called. Initiation. The polymerase unwinds then rewinds the DNA while adding to the mRNA with complementary bases from the cytoplasm. This step is called Elongation. WHen a termination signal is reached RNA polymerase and mRNA are released. This step is called Termination. It then leaves the nucleus via a nuclear pore.
3. Describe the sequence of events in translation to form a protein
A ribosomal (composed of a large and small ribosomal subunit) meets a mRNA in the cytoplasm of the cell. An initiator tRNA with the code UAC carrying the amino acid methionine meets and start codon AUG in the mRNA. This step is called. Initiation. Amino acids are added one at a time being being attached at site A. As the the mRNA slides through the ribosome the tRNA from site A moves to site P where it is attached to the polypeptide chain. The continues to slide moving tRNA from site P to site E where it is released. This step is called Elongation. These steps are repeated until a stop codon is reached (UGA, UAA, UAG) in site A and the polypeptide is released. This step is called Termination. The mRNA can then be used again to make another copy of the same protein.
4. Explain the process by which some proteins explain are produced in the rER and modified on the golgi
A ribosome attaches to the rER and can either become integral, or peripheral protein within the membrane of the rER OR it can be sent to the Golgi via a contained vesicle. The vesicle then merges with the Golgi at the cis face. The proteins are then modified, packaged, and released by secretory vesicles from the trans face. They are then serve as either lysosomes or merge
with the cellular membrane functioning as peripheral or integral proteins releasing protein into the. They can also be secreted into the extracellular fluid via exocytosis. This system is called the endomembrane system.
1. Describe the structure of the plasma membrane including lipid, protein, and carbohydrates
The cell membrane is a phospholipid bilayer with proteins, lipids, and carbohydrates. The bilayer is two sheet of phospholipid molecules arranged so fatty acids tails are facing each other. Cholesterol stabilizes. The membrane is fluid allowing molecules to move around. Integral proteins embedded through the membrane, peripheral proteins bound to the outer or inner surface. They create channels/pores through the membrane allowing non polar molecules to pass through. Carbohydrates called gylcocalyx hang off the outside of the cell connecting cell together and anchoring to extracellular material. They provide lubrication and allow for reconiction of cells by immune system.
2. List the 6 major classes of membrane proteins and explain their roles
Transport proteins help substances through the hydrophobic membrane Receptors bind chemical signals from other cells and trigger a response Anchoring proteins tie membrane to cytoskeleton and to extracellular molecules Membrane enzyme catalyze reactions at cell surface
Celltocell proteins all cells to bind with neighbours
Recognition proteins allow cells to identified by other cells
3. Explain how membrane is able to regulate transport of materials across the plasma membrane and to segregate compartments within the cells
Two groups of transport. Passive processes do not require energy expenditure to move something through the plasma membrane. Active processes requires ATP in order to move something through the plasma membrane. Permeability is the ease with which substances can cross the cell membrane. Impermeable nothing passes. Freely permeable anything can cross. Selectively permeable are selectively permeable.
4. Define the term isotonic, hypotonic and hypertonic and understand the consequences of placing cells into fluids of different tonicity
Isotonic means in equilibrium. Cells contain the appropriate amount of fluid. Hypotonic extracellular fluid has a lower concentration of solutes causing a flood of water into the cell making the cell swell and possibly burst. Can also be described as a high concentration of fluid outside the cell moving water inside the cell. Called hemolysis in red blood cells. Hypertonic is a higher concentration of solutes outside the cell causing water to move outside the cell making the cell shrink. Can also be described as a low concentration of fluid outside the cell moving water outside the cell. Called centration in red blood cells.
Lecture 2 objectives
1. Explain why carbon is the core of Organic Molecules
Carbon has 4 valence electrons thus allowing it to from 4 bounds. Carbon can form single bounds, double, and triple bounds.
2. Describe the basic structure of each of the four classes of Organic molecules, and where they are used in the body
Lipids mostly carbon and hydrogen, lack charges making them hydrophobic not attracted to water. 5 classes: Phospholipids and Glycolipids Cell membranes Fatty acids energy storage and building blocks Triglycerides three fatty acids attached by dehydration synthesis to one molecule of glycerol Glycerides building blocks Steroids cholesterol and sex hormones, corticosteroids regulate metabolism, important in lipid digestion, Eicosanoids signaling hormones Phospholipids polar on one end and non polar on the other Phosphorus (head), glycerol backbone, 2 fatty acid chains (tail)
Carbohydrates Typically have an H and an OH, “sugar group” important for energy, charged > hydrophilic, monosaccharides 1 sugar molecules Disaccharides 2 or more sugar molecules, Glycogen the polysaccharides storage of glucose
Proteins 20 Amino acids (R)
(Carbon, amino group, carboxylic acid, and R group), used for support and movement. enzymes have many functions (transportation, catalysis, pH, metab, body defense, and protein management). Some charged, some hydrophilic some hydrophobic. acid and amino group interact and form peptide bond (release of H2O).
primary: linear sequence of aminos
secondary: helix sheet, beginning of interactions (alpha sheets: spiral, h bonds. beta sheets: zigzags, pleated, h bonds)
Tertiary (globular): final shape, sensitive to pH and temp, globular form held together by intermolecular bonds
quaternary: globular proteins meet, these proteins are only active when out together
Nucleic Acids Made of Nucleotides containing Phosphate group (PO4), sugar group, nitrogen containing base Types of Nitrogen bases: Purines double ring molecules (adenine, guanine) Pyrimidines single ring (cytosine, thymine, Uracil) Makes DNA ( Phsophate, suagr, base) and RNA. Phosphate ends held together by hydrogen bounds
3. Describe the structure of ATP and relate it to its ability to power chemical reactions in the body
Made by adding a phosphate group to adenosine diphosphate (ADP Adenine, ribose, 2 phosphates) in a process called Phosphorylation. ATP (Adenine, ribose, 3 phosphates) is a high energy compound, that energy can be released during ATP hydrolysis which is the removal of a terminal phosphate group.
Lecture 1 objectives
1.Describe the different kinds of chemical bonds
Covalent Bonding between 2 nonmetals; sharing of electrons creating bounding Polar sharing electrons unequally
Nonpolar sharing electrons equally
Ionic Bonding between a metal and nonmetal: complete transfer of electrons resulting in two charged atoms that are then attracted to each other
Cation + charged ion
Antion charged ion
Hydrogen bonding because hydrogen is the smallest atom it usually has polar bonds which results in a partial positive charge which allows for weak attraction to a negative ion
2.Explain the structure of water and how it works as a solvent
The structure of water is bent, which means it has a + pole and a pole due to an unequal sharing of electrons, water molecules are held together but easily broken electron bounds and are attracted to any solute with charged atoms
3. Explain the relationship between pH and concentration of hydrogen ions in a solution and relate this to the pH values of key body fluids
The lower the pH the higher the H+ concentration, more acidic
The higher the pH the lower the H+ concentration, more basic
Blood is relatively neutral mean there are = amounts of H+ and OH ions, stomach acid is very acidic so there is a high [H+]
4. Describe the process which enzymes catalyze reactions
Reactants (substrates) interact to yield a product by binding to the active site of the enzyme to form a temporary enzyme substrate complex. The ES substrate undergoes internal reorganization that forms a product and is released.
Decreases activation energy, thus making a reaction more likely
Not used up in reaction
Very sensitive to temperature and pH change
Stability of the body allows for optimal reactions
Lecture Objectives 10
1. Define the term joint and understand the relationship between joint structure and degree of mobility
Joint is any place where two bones meet. Not all joints have movement. There are different degrees of mobility. Mobility is inversely related to stability. The more movement, the less stable. The more stable the less movement.
Different types of connective tissue
Connective tissue proper Fibrous joints
Cartilage cartilaginous joints
Combination synovial joint
*injury often is of the connective tissue rather than the bones*
Joints are encased in joint capsule or articular capsule which include a fibrous layer surrounding and a synovial membrane. The synovial membrane releases a slippery lubrication that fills the joint cavity (space between the bones). At the point of contact of either bone there is articular cartilage, which is hyaline cartilage that never turn to bone.
All synovial joints have stabilizing ligaments (dense regular connective tissue that fuses fuses into or on the joint capsule.
2. Explain features that determine the shape and size of a bone
Bone thickness reflects the amount of weight it supports. Ridges and bumps on bones are sites of muscle attachment. The amount of bone increases with stress. There are openings and spaces that create passageways for air, food, blood vessels, nerves, etc. Again in shape, Mobility is inversely related to stability. The more movement, the less stable. The more stable the less movement.
3. Describe the organization of the axial skeleton and the body cavities it protects
Axial skeleton contains the thoracic cage, vertebral column, and skull. It functions to protect organs, provides attachment for limbs.
The skull protects the brain with a network of suture joints held together by fibrous connective tissue. One point of weakness where four bones meet. Within the cranial
cavity there are depressions that cadel the coreestpoinf lobes. Small paired holes called foramina allow cranial nerves to communicate with in head. Foramen Magma. The largest of the foramina, where the holes where spinal cord meets the brain. Infant skulls are not fully formed to allow for passage through birth canal and final growth of brain. “Soft spots” are called fontanelles. Paranasal sinus hollow spaces within some skull bones lighten weight of skull and add resonance for speech. The orbit houses eyeball and eye muscles. The oral cavity houses moth muscles, including tongue salivary glands.
Vertebral column protects spinal cord. 7 cervical vertebrae, 12 thoracic vertebrae, 5 lumbar vertebrae, sacrum, coccyx. Stronger/ thicker near the bottom of spin b/c supports more weight.
*Curves are exaggerated/not drawn to scale in image*
Thoracic and sacral curves are sometimes called accommodation curves because the are present from birth to accommodate for growth of internal organs Cervical and Lumbar curves are sometimes called compensation curves because they appear after birth an account for weight shits for upright posture
Kyphosis Exaggeration in the thoracic curve
Lordosis exaggeration in the lumbar curve (pregnancy)
Scoliosis abnormal alter curvature
Houses and protects lungs and heart. The diagram separates the a thoracic cavity from the abdominal cavity.
Rib cage provides attachment for muscles of respiration and vertebral column and limbs. The sternal angle is palpable landmark used to locate the second rib. Ventral Medial part of ribs are actual cartilage shock absorber when palpating Abdominal muscles stretch with to accommodate structures within.
4. Describe the organization of the appendicular skeleton and explain the similarity in the pattern between upper and lower extremities
The appendicular skeleton contains the upper and lower limbs and the pelvic and pectoral girdles.
Girdle series of bones connecting limbs to trunk
Single long bone proximal two long bones in distal limb
Series of small bones in wrist and ankle
Lower limb bones are stronger and thicker bc more weight bearing. The hip is more stable thus less mobile than the shoulder because it is weather bearing. Some loss mobily is offset by long femoral neck.
Comparison of forearm and leg:
Radius and ulna of equal size
Move relative to one another
Mobility at expense of stability
Weight bearing tibia of much greater size than fibula
No significant movement relative to one another
stability at expense of Mobility