Week 8 LS 2 Notes
Week 8 LS 2 Notes Life Sciences 2
Popular in Cells, Tissues, and Organs
Popular in Biology
This 9 page Class Notes was uploaded by Jenna Kovsky on Friday November 20, 2015. The Class Notes belongs to Life Sciences 2 at University of California - Los Angeles taught by Dr. Cooper/Dr. Esdin in Fall 2015. Since its upload, it has received 46 views. For similar materials see Cells, Tissues, and Organs in Biology at University of California - Los Angeles.
Reviews for Week 8 LS 2 Notes
Report this Material
What is Karma?
Karma is the currency of StudySoup.
Date Created: 11/20/15
111615 Lecture 21 Musculoskeletal Svstem cont amp lmmunoloqv o Sarcoplasmic reticulum modified smooth endoplasmic reticulum where calcium comes from in muscle cells 0 transverse tubules increase surface area for depolarizationpropagation of the electrical current TTubules O O invaginations have voltage sensing channels DHPR in close proximity to on the lateral sacs of the sarcoplasmic reticulum what triggers Ca release O 0000 at Neuromuscularjunction synapse between a neuron and a muscle cell action potential of neuron opens VGCC at the axon terminal leads to NT release the NT here is Acetylcholine ACh ACh binds to ACh receptors on the muscle cell membrane End Plate Potential EPP a graded potential stimulated in a muscle cell from a neuron EPPs bring muscle to threshold and that brings the muscle cells to an action potential VGSC open just like in a neuron action potential propagates down the muscle cell down the TTubules whose DHPR open with the voltage which allows calcium to go to the muscle cell cytosol from the sarcoplasmic reticulum 0 Cross Bridge Cycle 0 Calcium binds to troponin so troponin and tropomyosin move out of the way so myosin can bind to actin in the ready state myosin had ADP and Pi not ATP bound to it this is the myosin s high energy state energy was released by ATPase when it broke down ATP on the myosin and that energy went to the myosin after myosin and actin bind Pi is released and the myosin pulls the actin power stroke this is when the contraction occurs because the sarcomere shortens at the power stroke myosin loses affinity for ADP and that is released allowing a new ATP to bind When ATP binds myosin and actin dissociate What stops this cycle I two major steps 0 removing ACh broken down by ACh Esterase o Ca2 is returned to the Sarcoplasmic Reticulum SR using pumps on the SR I gives a chance for the muscle to relax until the next action potential comes from the neuron 0 Where does the muscle get energy from O 0 muscle gets glucose and oxygen to produce energy there are 3 sources of energy I creatine phosphate minimal stored form of energy small amount of ATP phosphate bound to creatine o creatine kinase gives you creatine ATP 0 in vertebrates while arginine phosphate in invertebrates 0 both are phosphagens 0 CP is a very quick source of energy but it only lasts for a second is depleted quickly I cellular respiration o is kicking in while CP runs out o muscles are packed with mitochondria and have lots of blood vessels 0 muscles store oxygen in myoglobin I glycolysis followed by fermentation 0 when oxygen demands exceed availability 0 fatigue not having energy molecules I do creatine supplements work 0 claims are not evaluated by FDA 0 at first works but the effect wears away soon honeymoon o don t work for average daily life 0 limitation of delivery and limited amount of enzyme 0 Tetanus O O O O o Botox OOOO Clostridium tetani a toxin produced by bacteria that live on metals toxin affects inhibition of the muscles so muscles are more excited lockjaw Clostridium botulinum used to get rid of wrinkles wrinkles are over excitation of muscle neurons so muscles of the face are contracted toxin that inhibits the release of NT from the motoneurons IMMUNOLOGY ANIMAL DEFENSE SYSTEMS 0 function protect your body against infection and microbes isolates and removes non microbial foreign substances 0 Pathogens O O 0000 we are unlimited source of nutrients for pathogens pathogens enter our body through any of our openings including temporary ones like cuts they like to go to livers guts or muscles where there are lots of nutrients something that shouldn t be inside our body parasite something that feeds off of us multicellular organism usually a worm bacteria prokaryotes unicellular O O protist unicellular fungi like yeast athlete s foot can be on outside of body or inside virus nonliving organisms once they invade the cells they take over the protein machinery and reproduce quickly 0 Organization of the Immune System nonspecific immune response protects against foreign substances without having to recognize their identity I prevention 0 physical barrier thick layers of protection especially the O 0 skin fibrous layers of the eye mucus membrane any inner lining in respiratory digestive urinary and reproductive organs skin cells produce so much keratin that they cannot survive anymore 0 chemical barrier each phys barrier releases chemicals O 0000 0 skin produces sebum an oily substance mucus and saliva in mouth and nose secrete defensins lacrimal glands produce tears constantly wash the eye tears have lysozymes wax in the ears sweat mucus through reproductive openings macrophages in the lungs acid in the stomach o reflexes sneezing coughing I a ack specific immune response highly specific recruited if nonspecific can t take care of it 0 Where are microorganisms EVERYWHERE o isolate pathogens with sterile cotton swab and apply to culture dish 111815 O 0000 Lecture 22 Immune Svstem lcont o Lymphoid tissues clustersorgans that make immune cells or places where immune cells are stored Adenoids Tonsils Thymus a lot of immune cells mature Lymph Nodes pathway for immune cells to travel spleen Bone Marrow form of connective tissue inside bones where many types of immune cells mature and are released into circulation contains pluripotent hematopoietic stem cells that become myeloid stem cells that differentiate into a specific type of immune cell Immune cells 0 O basophils attack parasites neutrophils most abundant phagocytes release cytokines chemicals to increase alertness and recruit other immune cells vasodilators increase diameter of blood vessels and chemotaxins direct immune cells to the site where they re needed mast cells not in direct contact with pathogens release chemicals to recruit immune cells release histamines type of cytokines monocytes macrophages when they are in circulation macrophages monocytes that have been recruited to attack engulf endocytose and digest recruit T cells binds to bacteria then engulfs function is to attack anything that doesn t belong in the body eosinophils dendritic cells B lymphocytes transform into plasma cells and release antibodies into the circulation form memory cells efficient because antibodies a protein have a sequence that matches the pathogen and keep track of amino acid sequencegtimmunization cytotoxic T cells release chemicals bind to cancer cells release enzymes into the cancer cell perforin and granzymesenzymes that digest macromolecules and activate Fas receptor to induce apoptosis Pathogen invasion 0 O Inhalation Tonsils and macrophages in lungs hair cells in nose etc as defense Skin penetration I a lot of bacteria can invade and enter circulation I nonspecific immune responseinflammation 0 occurs through out or injury to the skin 0 sequence of events ensue to protect the body against infection 0 phagocytosis and recruitment macrophages in the area are quick to start endocytose microbes send signals cytokines to recruit other immune cells mast cells release histamine injured cells release chemotaxins o vasodilation and increase in permeability blood vessels widen and get more permeable endothelial cells increase the spaces between them swelling edema o phagocytic cells miqration phagocytic cells could be macrophages or neutrophils I macrophages don t travel with the flow of the blood I margination macrophages travel on the side of the blood vessels by matching up their receptors endothelial cells express receptors called selectin and phagocytic cell has integrin on their membrane I diapedesis process in which phagocytes move out of the blood vessel into the site of injury which they recognize due to chemotaxins chemoattractants I phagocytes bind and engulf pathogen 0 Attachment 0 Opsonization physical binding before endocytosis receptors on surface of macrophages must match on pathogens Internalization now called a phagosome Degradation enzymes of lysosomes merge with phagosome to form phagolysozome intracellular digestion o Elimination of Debris exocytosed 0 Tissue Repair I Extracellular Destruction 0 Complement Svstem Leads to activation of pores fluid rushes into cells causing cells to burst lysis o Immunization give you a small nonharmful samesequence protein produced by the pathogen This recruits memory cells but sometimes can be harmful and recruit 0 Allergy overactive Immune system eg immune system recruits due to something like dust take antihistamine to reduce histamines overproduced by immune system 0 epinephrine shot epipen 0 AIDS Acquired Immune Deficiency Syndrome o from a virus 0 die of opportunistic infections 0 don t have any immune cells 0 Autoimmune Diseases immune system turns on a certain type of cell in the body 0 self has receptor so immune system knows it belongs in the body 0 nonself cell does not have receptor 0 Eg Type 1 Diabetes immune system attacks pancreatic beta cells that produce insulin so the body can no longer produce its own insulin 0 eg Multiple Sclerosis immune system attacks myelinproducing cells ENDOCRINE SYSTEM 0 The Endocrine System sidekick to nervous system major communication system consists of many glands throughout the body hormones rely on the blood to reach target cells gland an organ that secretes hormones that act as chemical messengers I Major only for releasing hormones OOOOO pineal gland hypothalamus pituitary gland parathyroid glands thyroid gland thymus gland heart stomach adrenal gland Mdney pancreas small intestine ovariestestes 112015 Lecture 23 Endocrine Svstem cont 0 Blood has to be available for hormones to travel 0 the cells that respond to the hormone must have an appropriate receptor 0 Chemical Composition of Hormones o can be made of steroids or peptides I steroids cholesterolmodified products lipophilic can permeate through the plasma membrane receptor is intracellular I peptides made of chain of amino acids cannot permeate into the cell so receptor is on the cell membrane extracellular I 3rd class or hormones amines modified single amino acids synthesis can vary I peptides produced in Rough ER then goes to Golgi which modifies it from preprohormone to prohormone 0 most peptide hormones are stored as prohormones 0 upon release from cell get converted to the actual hormonal state secretion can vary I peptides are released by exocytosis I steroids released by simple diffusion travelling in blood I proteins travel freely in blood I steroids must have carrier proteins transport them in the blood because the blood is mostly water so it doesn t interact well chemical structure determines their mechanisms of action on target cells I steroid receptor inside the cell sometimes in the nucleus nuclear receptor or in the cytosol cytosolic receptor 0 HRE Hormone Response Element binding site for hormone receptor 0 binds to HRE directly on the part of the DNA to change gene expression 0 leads to synthesis of a new protein which causes a response 0 O O O I peptide binds to extracellular receptor 0 eg GPCR GProtein Coupled Receptor 0 causes chain of events within the cell that leads to a cellular response 0 Hormonal Secretion o Humoral the gland is measuring a certain factor being measured in the blood and decides whether to release hormone or not based on levels in circulation of a chemical I eg Parathyroid gland low Ca2 level in bloodgtParathyroid hormone PTH release a peptide hormonegtincreases Ca2 by releasing it from the bones 0 receptor Parathyroid glands 0 control center parathyroid glands o effector o Neural nervous system decides signals firedsent from nervous system to a gland I eg Adrenal Medulla signal from spinal cordgtstim Adrenal Medullagtepinephrine release amine 0 Hormonal gland releases a hormone that acts on another gland to release its own hormone o Hypophysis gland suspended from the brain behind the nose extremely small 0 produces 8 vital hormones all peptides 0 made of two different types of tissue I anterior pituitary closer to nose made of epithelial tissue I posterior pituitary closer to occipital made of neurons neurohypophysis o Neurohypophysis posterior pituitary I cell body axon hillock and part of the axon are in the hypothalamus I Supraoptic nucleus and Paraventricular nucleus clusters of the cell bodies in the hypothalamus I hormones are technically produced in the hypothalamus but stored and released in the posterior pituitary I releases 2 hormones o Antidiuretic Hormone ADH minimizes water loss target kidneys o if you have excess water then you don t want to release this 0 if you re sweating a lot then you do want to release it o Oxytocin induces smooth muscle contraction released in females during birth and lactation 0 targets Uterus mammary glands o hormone of bonding o Adenohypophysis Anterior Pituitary I 6 peptide hormones o follicle stimulating FSH and luteinizing hormone LH 0 target gonads sex cells 0 both released from both females and males 0 produce gametes sperm or eggs and sex hormones testorterone or estrogen Thyroid HormoneTSH 0 target Thyroid 0 increases rate of metabolism Adrenal CorticoTropic Hormones ACTH 0 target Adrenal Cortex o helps body cope with stress Prolactin 0 target mammary glands 0 produces milk Growth Hormone GH 0 targets liver bones muscles etc o promotes growth I Hypothalamus releases chemicalsfactorshormones DAPRL 0 negative control 0 Hypothalamus releases dopamine so prolactin is not released 0 prolactin released when dopamine is NOT released GnRH FSH LH o Gonadotropin Releasing Hormone TRH TSH CRH ACTH GHRH 88 GH 0 What stimulates the Hypothalamus o HypothalamicPituitaryAdrenal Axis I Hypothalamus releases CRH I CRH stimulates Anterior Pituitary to release ACTH I ACTH stimulates Adrenal Cortex to release Cortisol Cortisol hormone that helps you deal with stress a threat to Homeostasis when your body is threatened it interprets as your body needing nutrients body starts to make sure that certain parts of your body eg Brain get enough nutrients I Cortisol steroid hormone increases plasma concentrations of glucose for the brain fatty acids for other tissues and amino acids increases fuel availability to the brain gluconeogenesis lipolytic hormone induces breakdown of fat antiinflammatory effects immunosuppressive interferes with immune system function affects memory function proteolytic hormone breaks down proteins bad thing prevents growth I There is a set point for cortisol in the Hypothalamus NEGATIVE FEEDBACK LOOP not a lot of cortisol in the blood