Exam 3 Review

Immune and Endocrine SystemsAN S 214 Supplemental Instruction

3/31/13

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

Cells of Immune System

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

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

Mechanism of Phagocytes1. Phagocyte adheres to pathogens

or debris2. 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

Injury to Healing Flow Chart

Adaptive Defenses

• Cell Mediated Immunity– T Cells

• Humoral Immunity– B Cells

• Specific • Systemic• Has memory

Cell Mediated Immunity

• CD4 + MHC II = Clones Helper T Cells– Activate immune

response • Stimulate B cells

• CD8 + MHC I = Clones Cytotoxic T Cells– Release perforin and

granzymes

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

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

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

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

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

Pituitary Hormones

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

Hormone Secreted from (cell type?)

Triggered by… (which hormone?)

Effects

GH Somatotrophs GHRH (stimulate)GHIH (somatostatin) (inhibit)

Direct: Fat and carbohydrate metabolismIndirect: Stimulates the release of IGFs, which affects skeletal and extraskeletal

FSH Gonadotrophs GnRH Stimulates gamete productionLH Gonadotrophs GnRH Stimulate gonadal hormone production

PRL Lactotrophs PRH (stimulate)PIH (dopamine) (inhibit)

Stimulates milk production

TSH Thyrtrophs TRH Stimulates thyroid developmentACTH Corticotrophs CRH Regulates to response to stress

Stimulates the adrenal cortex to release corticosteroids

Oxytocin Hypothalamus XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX

Stimulates milk ejectionStimulates uterine contractions

ADH Hypothalamus XXXXXXXXXXXXXXXXXXXXXX Inhibits urine production

Thyroid HormoneA – Thyroglobulin synthesized/discharged into

follicle lumenB – Iodide (I-)is actively transported inNot labeled – Iodide is oxidized to Iodine C – Iodine is attached to tyrosine in colloidD - Iodinated tyrosines are linked to form T3 &

T4E - Thyroglobulin colloid is combined with

lysosomeF - 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

Blood Glucose Levels

• Pancreas– Insulin

• Decreases blood glucose levels

– Glucagon• Increases blood

glucose levels

Hormone Abnormalities • 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

• Type II

– Hyposecretion• Insufficient insulin

results in polyuria, polydipsis, polyphagia

• Type I

• 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

Blood Calcium Levels • Parathyroid Hormone

– Produced by parathyroid gland– Increases blood calcium levels

• Calcitrol (Activated Vitamin D)1. UV radiation and epidermal

keratinocytes convert steroid derivative to cholecalciferol – D3

2. Liver converts it to calcidiol3. Kidney converts that to calcitrol

– Increases blood calcium levels • Calcitonin

– Produced by parafollicular cells– Decreases blood calcium levels

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

Mechanisms of Hormone Action

• Target cell must have specific receptors to which the hormone binds– Water-soluble hormones– Lipid-soluble hormones

Water-Soluble Hormones• Amino-acid based hormones1. Hormone binds receptor (1st

messenger)2. Receptor activates G protein3. G protein activates adenylate

cyclase 4. Adenylate cyclase converts

ATP to cAMP (2nd messenger)5. cAMP activates protein

kinases

Lipid-Soluble Hormones• Steroid-based hormones and

Thyroid Hormone1. The steroid hormone diffuses

through the plasma membrane and binds an intracellular receptors

2. The receptor-hormone complex enters the nucleus

3. The receptor-hormone complex binds a hormone response element (a specific DNA sequence)

4. Binding initiates transcription of the gene to mRNA

5. The mRNA directs protein synthesis

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