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Test 1 Study Guide- Glands (2 types)o Exocrine – ducts leading to external environment Merocrine = cell secretes product Apocrine = cell pinches off with secretory product inside,  Holocrine = entire cell goes off with product and disentigrateso Endocrine – ductless/secrete hormones into blood- Homeostasis balances autonomic branches of the nervous system – parasymtpathetic and sympathetic. Usually negative feedback.o Sensor detects regulated variable, sends to integrating center, integrating center compares to set point = error signal, integrating center sends output to effectors to return back to set point.o- Positive feedback loop – stimulus must end for response to end.o- Chemical Messenger Typeso Autocrine = local communication, receptor on same cello Paracrine = local communication, neighboring cello Cytokines = peptides or proteins, for cell development, differentiation,and immune responseo Neurotransmitter = mostly amino acids, hydrophilico Neurohormone = neuron secretes into bloodo Hormone = released into blood to target cell with receptoro Types of messenger : Amino acid based = amine (amino acid with amine group), peptide/protein (prepropeptide  propeptide  peptide) Steroid = hydrophobic, made from cholesterol. Uses direct gene activation. Eicosanoids = includes prostaglandins, made from lipidso Hydrophobic messengers needs carrier in blood and cytosol, either cytosolic or nuclear, slower response (for release can just diffuse out),longer half-life because it is boundo Hydrophilic can’t pass membrane so need a surface receptor, fast response (for release, it must be exoctyosed).- Hormone Interactionso Antagonism = two hormones effects oppose each other, like glucagon and insulino Additive = summation of two hormones, use different receptors, seen in GHo Synergism = two hormones favor each other, exceeds sum, like glucagon and cortisol on blood glucoseo Permissiveness = need one hormone for another to work, such as a steroid (estrogen) causing expression of a receptor (oxytocin receptor) so oxytocin can work in the uterus- Hormone levels are controlled through secretion, amount bound, metabolism, and half-life. The magnitude of response depends on the concentration of messenger, number of receptors present on or in cell, and receptor affinity for ligand. When too much messenger the receptor can be down regulated, when to little  up regulation … this is done by altering shape to change affinity or changing the number of receptors.o Case study = Androgen Insensitivity Syndrome (AIS) – cant bind androgens, so unresponsive to testosterone- Pathologies in secretiono Primary = problem with organ secreting hormoneo Secondary = pituitary tropic hormone problemo Tertiary = problem with hypothalamic tropic hormone- Signal transduction = signal molecule  receptor  intracellular signal  target protein  response- Membrane Receptor Typeso Enzyme-linked – ex. Tyrosine kinase and guanylate cyclase (GTP to cGMP)o G-protein coupled Gas = stimulatory, stimulates adenlyate cyclase to make cAMP, hormone binds receptor  G-protein binds receptor and GTP replaces GDP  alpha subunit dissoaciates and activates adenylate cyclase  cAMP  activates PKA- Epi, glucagon, LH, PTH, and ACTH use this pathway- cAMP degraded by phosphodiesterase to stop response Gai – inhibits adenylate cyclase, lowering cAMP- GHIH/SST aka SMS Gaq = activates PLC  cause conversion of PIP2 to IP3 (intracellular calcium release, leading to electrical changes, exocytosis, muscle contraction, ca-calmodulin complex to activate protein kinase) and DAG (activation of PKC)- Vasopressin/ADH, TSH, Angiotensino Channel-linked/ligand gated You know it, faster when receptor is on channel, slower when G protein coupledo Exogenous agonists and antagonists can alter the feedback loop, like ifyou take testosterone you’re testes will shrink because they do not need as much testosterone (side note made in class)- Hormonal release can be caused by hypothalamic stimulation, pituitary stimulation, a humoral response (stuff in the blood such as low calcium orblood sugar), or circadian rhythms which use melatonin (ex. Varying levels or cortisol and GH)- Hypothalamus and endocrine glands have different groups of cells that secrete different products, so if you have a tumor, different locations will have different pathological effects.-- Hypothalamuso Uses releasing and inhibiting hormones and is the master control.o Makes neurhormones that are stored at nerve endings, released in pulses into portal veins (hypothalamic-hypophyseal).o Receives short loop (pituitary product) and long loop feedback (final product)o Classes of hypothalamus hormones Neuropeptide hormones- ADH- Oxytocin Hormone-releasing hormones- GnRH - Gq pathway- TRH (Thyrotropin Releasing Hormone)- GHRH – - CRH- PRF/PRH – messenger system not well studied, G-protein Hormone-release inhibiting hormones - GHIH/SST/SMS – blocks secretion of GH, TSH, and prolactin, Gi pathway- PIH/PIF – aka dopamine, Gi- Pituitary Gland (figurehead)o Anterior (glandular) (Adenohypophysis) TSH (Thyrotropin) - Targets thyroid- Glycoprotein, Gs- Pathologieso Hyperthyroidism = increased thyroid hormone leading to hotness, weight loss, and irregular heart beato Hypothyroidism = weight gain, intolerance to thecold ACTH – targets adrenal cortex- Gs GPCR, cAMP stimulates mobilization of cortisol from lipid droplets to make steroid hormones like cortisol.- Derived from the poly-protein propiomelanocortin (POMC)- Pathologieso Hypersecretion Cushing’s syndrome (buffalo hump, obesity, muscle weakness). Over suppression of the immune system. High BP, hyperglycemia, weak bones, depression. Masuclanization from androgen hypersecretion.o Hyposecretion Addison’s syndrome, can’t adapt to stress well without cortisol. Bronze skin tone, weak muscles. You get more progenitor hormone POMC because it is the ACTH precursor, so you build up other compounds from more melanocyte-stimulating hormone and gain fearlessness from endorphins. FSH – targets testes/ovaries, sperm and follicle development respectively, glycoprotein that uses Gs LH – targets testes/ovaries, testosterone production and ovulation respectively, glycoprotein that uses Gs GH- Targets entire body- Gs pathway- Growth of skeletal muscles and long bones (stimulates IGF-1 in liver causing cell division/tissue growth), breakdown

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UMD BSCI 447 - Test 1 Study Guide

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