Exam 3 Review

1. Exam 3 Review Immune and Endocrine Systems AN S 214 Supplemental Instruction 3/31/13

2. Immune System Outline • Cells of Immune System • Innate Defenses • Surface Barriers • Internal Defenses • Injury to Healing Flow Chart • Adaptive Defenses • Cell Mediated Immunity • Humoral Immunity • Forms of Immunity • Words to Know

3. Cells of Immune System

4. Innate Defenses • Surface Barriers • Skin • Acidity • Enzymes • Mucin • Defensins • Lipids • Keratin • Mucus Membranes • Internal Defenses • Natural Killer Cells (Police) • Large granular lymphocyte • Induce apoptosis • Non-specific • Fever • Inflammation • Heat • Redness • Swelling • Pain • Impairment of Function • Phagocytes

5. Phagocyte Mobilization • Leukocytosis – Neutrophils enter blood from bone marrow • Margination – Neutrophils cling to capillary wall • Diapedesis – Neutrophils flatten and squeeze out of capillaries • Chemotaxis – Neutrophils follow chemical trail

6. Mechanism of Phagocytes 1. Phagocyte adheres to pathogens or debris 2. Phagocyte forms pseudopods that eventually engulf the particles forming a phagosome 3. Lysosome fuses with the phagocytic vesicle, forming a phagolysosome 4. Lysosomal enzymes digest the particles, leaving a residual body 5. Exocytosis of the vesicle removes indigestible and residual material

7. Injury to Healing Flow Chart

8. Adaptive Defenses • Cell Mediated Immunity • T Cells • Humoral Immunity • B Cells • Specific • Systemic • Has memory

9. Cell Mediated Immunity • CD4 + MHC II = Clones  Cytotoxic T Cells • Release perforin and granzymes • CD8 + MHC I = Clones  Helper T Cells • Activate immune response • Stimulate B cells

10. Humoral Immunity • Antigen + Naïve B Cell = Clones  Memory B Cells + Plasma B Cells • Plasma B Cells • Antibodies • Precipitation • Lysis by Complement • Agglutination • Neutralization • IgM • IgA • IgD • IgG • IgE

11. Forms of Immunity • Primary • Mostly IgM, lag period, antibodies don’t last as long • Secondary • Mostly IgG, faster and larger response, antibodies last longer • Active, Natural – Infection • Active, Artificial – Vaccine • Passive, Natural – Colostrum • Passive, Artificial – Injection of antibodies

12. Words to Know • Antigen – substance that can mobilize the adaptive defenses and provoke an immune response • Antigenic Determinant – part of the antigen that induces an immune response • Apoptosis – Cell death • Haptens – not immunogenic by themselves, immunogenic when attached to body proteins • Immunocompetence – (lymphocytes) able to recognize and bind to a specific antigen • Immunogenicity – ability to stimulate proliferation of specific lymphocytes and antibodies • Reactivity – ability to react with activated lymphocytes and antibodies released • Self-Tolerance – (lymphocytes) unresponsive to self antigens

13. Endocrine System Outline • Types of Stimuli • Pituitary Hormones • Thyroid Hormone • Blood Glucose Levels • Hormonal Abnormalities • Blood Calcium Levels • Blood Calcium Abnormalities • Mechanisms of Hormone Action • Water-Soluble Hormones • Lipid-Soluble Hormones • Words to Know

14. Types of Stimuli • Humoral Stimuli • Changing blood levels of ions and nutrients directly stimulates secretion of hormones • Neural Stimuli • Nerve fibers stimulate hormone release • Hormonal Stimuli • Hormones stimulate other endocrine organs to release their hormones

15. Pituitary Hormones • Anterior Pituitary Hormones (Adenohypophysis) • Posterior Pituitary Hormones (Neurohypophysis)

16. Thyroid Hormone A – Thyroglobulin synthesized/discharged into follicle lumen B – Iodide (I-)is actively transported in Not labeled – Iodide is oxidized to Iodine C – Iodine is attached to tyrosine in colloid D - Iodinated tyrosines are linked to form T3 & T4 E - Thyroglobulin colloid is combined with lysosome F - Enzymes cleave T3 & T4 from thyroglobulin colloid and hormones diffuse into blood • Major metabolic hormone • Maintenance of blood pressure • Regulation of tissue growth • Development of skeletal and nervous systems • Reproductive capabilities • T3 is ten times more active than T4

17. Blood Glucose Levels • Pancreas • Insulin • Decreases blood glucose levels • Glucagon • Increases blood glucose levels

18. Hormone Abnormalities • Thyroid Hormone • Hypersecretion • Grave’s disease • Hyposecretion • In Infants results in cretinism • In adults results in myxedema or endemic goiter if due to lack of iodine • Growth Hormone • Hypersecretion • In children results in gigantism • In adults results in acromegally • Hyposecretion • In children results in pituitary dwarfism • Insulin • Hypersecretion • Excessive insulin secretion results in hypoglycemia, disorientation, unconsciousness • Hyposecretion • Insufficient insulin results in polyuria, polydipsis, polyphagia

19. Blood Calcium Levels • Parathyroid Hormone • Produced by parathyroid gland • Increases blood calcium levels • Calcitrol (Activated Vitamin D) • UV radiation and epidermal keratinocytes convert steroid derivative to cholecalciferol – D3 • Liver converts it to calcidiol • Kidney converts that to calcitrol • Increases blood calcium levels • Calcitonin • Produced by parafollicular cells • Decreases blood calcium levels

20. Blood Calcium Abnormalities • Hypercalcemia • Excess blood calcium • Hypocalcemia • Deficiency in blood calcium • Milk Fever Prevention • Stimulate cow’s calcium mobilization before calving • Feeding a transition diet 3 weeks before calving • Increase dietary calcium immediately after calving • Avoid fat cows at calving • Administering vitamin D injection 2-8 days before calving

21. Mechanisms of Hormone Action • Target cell must have specific receptors to which the hormone binds • Water-soluble hormones • Lipid-soluble hormones

22. Water-Soluble Hormones • Amino-acid based hormones • Hormone binds receptor (1st messenger) • Receptor activates G protein • G protein activates adenylate cyclase • Adenylate cyclase converts ATP to cAMP (2nd messenger) • cAMP activates protein kinases

23. Lipid-Soluble Hormones • Steroid-based hormones and Thyroid Hormone • The steroid hormone diffuses through the plasma membrane and binds an intracellular receptors • The receptor-hormone complex enters the nucleus • The receptor-hormone complex binds a hormone response element (a specific DNA sequence) • Binding initiates transcription of the gene to mRNA • The mRNA directs protein synthesis

24. Words to Know • Antagonism – one or more hormones opposes the action of another hormone • Autocrine – chemicals that exert effects on the same cells that secrete them • Gluconeogenesis – synthesis of glucose from lactic acid and noncarbohydrates • Glycogenolysis – breakdown of glycogen to glucose • Half life – the time required for a hormone’s blood level to decrease by half • Homeostasis – The tendency of an organism or a cell to regulate its internal conditions, usually by a system of feedback controls, so as to stabilize health and functioning, • Hormones – long-distance chemical signals that travel in the blood or lymph • Negative Feedback – feedback that reduces output of a system • Paracrine – locally acting chemicals that affect cells other than those that secrete them • Permissiveness – one hormone cannot exert its effects without another hormone being present • Positive Feedback – feedback that enhances the output of a system • Rickets – bones don’t mineralize properly • Synergism – more than one hormone produces the same effects on a target sell • Tropic Hormones – regulate the secretory action of other endocrine glands