Chapter 18 - Endocrine System Lecture 4 PDF

Part 1: Levels of Hormone Interactions, Hormones from Other Organs, and General Adaptive Syndrome Part 2: Lipid Soluble vs Water Soluble Hormone Differences and Functionality Part #1:  Differentiate between antagonistic, synergistic, and permissive effects of hormones.  Identify and describe the e...

Part 1: Levels of Hormone Interactions, Hormones from Other Organs, and General Adaptive Syndrome Part 2: Lipid Soluble vs Water Soluble Hormone Differences and Functionality Part #1:  Differentiate between antagonistic, synergistic, and permissive effects of hormones.  Identify and describe the endocrine roles related to the kidney, the intestines, the heart, & the thymus.  Identify and describe the endocrine roles related to the gonads.  Describe the 3 stages of the General Adaptive Response (GAS). Part #2:  Compare and contrast free vs bound hormones noting lipid vs water-soluble, location of receptors, and longevity of the hormone.  Explain how steroid hormones and thyroid hormones function, including where receptors are found.  Explain how water-soluble hormones function, including where the receptors are found, and explain what a Gprotein is.  Compare and contrast the 3 secondary messengers, and identify the 2 that are excitatory and the 1 that is inhibitory.    Hormones cause different responses on tissues and may have unique effects when other hormones are present. Effects of 2 differing hormones are:1) antagonistic, 2) synergistic, and 3) permissive, meaning? Opposite/opposing effects like? ◦ PTH + Calcitonin; insulin + glucagon  Additive effects like? ◦ PTH + Calcitriol; ADH + aldosterone  The hormone of interest only works in presence of another hormone. ◦ Epi- and norepinephrine require normal levels of thyroid hormone.      Many organs have secondary endocrine functions. Kidney = 1o = waste removal/urine formation 20 = Calcitriol, erythropoietin (EPO), and renin production. Stimulates effects of PTH, stimulates osteoclasts, + increase calcium absorption via intestines. Stimulates red blood cell (RBC) production. ◦ stimulated by low O2 levels in kidney.   Enzyme that stimulates angiotensin II ➔ stimulates ADH and aldosterone release ➔ increase BP. (Details next page) Intestines - 1o = digest and absorb nutrients 20 = secrete hormones that regulate digestion   Heart monitors & generates? Pressure: produces natriuretic peptides (ANP/BNP)? ◦ Opposes angiotensin II, meaning? ◦ Decreases BP when blood volume and/or blood pressure are high. How? ◦ Increase output or stimulate/increase urination.  Inhibits “aquaporin” production that occurs in presence of ADH.  Thymus function? ◦ Site where T-cells mature; T-cells? ◦ Type of lymphocyte of adaptive immunity; ◦ Produces & secretes thymosins = thymic hormones that stimulate T-cell maturation.  Testes = produce testosterone = steroid hormone  development of sex characteristics    Primary develop as fetus; secondary at puberty sex drive, bone & muscle growth + spermatogenesis Ovaries = Estrogen & Progesterone (steroids). ◦ development of uterus and vagina (fetus). ◦ Body hair, + follicle/egg development (puberty)  Progesterone production (corpus luteum). ◦ mammary gland development (puberty) ◦ Maintains uterus – lack of pro = menstration (puberty).  Aka the stress response = pattern of hormonal and physiological adjustments due to stress (18.20). ◦ Broken down into 3 phases  1) Alarm Phase – “everyday stress” – sympathetic stimulation resulting in mobilization of energy reserves – cause by epi- and nor-epinephrine. ◦ Catecholamines (epi and nor) = water soluble = short lived response  2) Resistance Phase – stress longer than few hours – ALL energy hormones in play including steroid hormones from adrenal gland = longer lasting effects – reserves become severely depleted. Part 1: Levels of Hormone Interactions, Hormones from Other Organs, and General Adaptive Syndrome Part 2: Lipid Soluble vs Water Soluble Hormone Differences and Functionality Part #1:  Differentiate between antagonistic, synergistic, and permissive effects of hormones.  Identify and describe the endocrine roles related to the kidney, the intestines, the heart, & the thymus.  Identify and describe the endocrine roles related to the gonads.  Describe the 3 stages of the General Adaptive Response (GAS). Part #2:  Compare and contrast free vs bound hormones noting lipid vs water-soluble, location of receptors, and longevity of the hormone.  Explain how steroid hormones and thyroid hormones function, including where receptors are found.  Explain how water-soluble hormones function, including where the receptors are found, and explain what a Gprotein is.  Compare and contrast the 3 secondary messengers, and identify the 2 that are excitatory and the 1 that is inhibitory.  Hormones released in cir. unattached to protein.  Hormones that circulate attached to a transport protein. ◦ Water soluble hormones = peptide derivatives + catecholamines + tryptophan derivatives ◦ Remain functional for less than 1 hour ◦ Lipid soluble hormones + thyroid hormone ◦ Remain functional for longer periods.    Regardless of type, 2 processes can occur: 1) Bind to receptors ON target cells (effectors) causing a response/performing its function. 2) Broken down ◦ Recycled by liver OR removed by kidneys ◦ Destroyed by enzymes in plasma or interstitial fluid.  Think acetylcholinesterase   Steroid Hormones & Thyroid hormones (18.4) Activate genes for specific protein synthesis. ◦ Ex: testosterone, progesterone, estrogen (sex hormones), cortisol, and aldosterone.  a] activates genes/controls rates of transcription & metabolism via enzyme production. Or b] stimulates ATP production  Targets most cells; important for cell development.  MP: Lipid soluble hormones function by binding intracellular receptors, which often results in “gene activation”.  ALL water-soluble hormones ◦ Peptide hormones, catecholamines, and trypto: why? ◦ Not lipid soluble because? ◦ Large, polar, hydrophilic molecules  Requires 2 messengers (18.3) ◦ 1) First (indirect response) and 2) Second messengers  Peptide hormone that binds PM receptor & activates G protein. ◦ chemical intermediate that responses to 1st messenger & activates the second messenger.  Cytoplasmic molecule(s) that carries out actual response ◦ Activate genes, increase or decrease metabolism, etc     production of LOTS of second messengers (can be diff) in cell via activation of G proteins Based on intracellular enzymes, amplification can occur: big response to low horm. concentration. Cells influence responses by regulating receptors. Down regulation - decrease in # of hormone receptors when hormone conc. high. ◦ Cells becomes less sensitive. ◦ Dramatic decrease of sensitivity? ◦ Diabetes  Up-regulation - increase in # of effector receptors due to low hormone conc. ◦ Cell becomes more sensitive. ◦ Ex: Ovulation – LH receptors    Cytoplasmic chemical msnger (enzymatic activator, inhib. or coenzyme) that leads to cellular response. Ex: Calcium as Secondary Messenger (Msg) 1) Activated G Protein – stimulates opening of Ca2+ ion channel or release via intracellular components  Calcium Stimulates? ◦ Neurotransmitter (NT) release ◦ Muscular contraction ◦ Binds with/activates Calmodulin   Activates cytoplasmic enzymes Main Points (MPs): ◦ Activation of G protein → stimulates intracellular conc. of calc. → calc. has many functions ◦ Main func. = actives Calmodulin   An ATP derivative that alters cellular activity based on intracellular conc. 1) Activated G Protein – increases or decreases conc. of cAMP levels intracellularly depending on enzyme available. ◦ Excitatory effects = increase cAMP; Inhibit = decrease  cAMP increases when G-protein activates adenylate cyclase ➔ ◦ Converts ATP to cAMP.   cAMP – a) activates a Kinase – an enzyme that phosphorylates (activates) another molecule by attaching a high energy phosphate group to it. b) opens ion channels  When G-protein activates phosphodiesterase (PDE) ◦ Breaks cAMP down to AMP ➔ less cAMP = decreased enzymatic activity = decreased cellular activity  MPs of cAMP ◦ High conc. = more activity. ◦ Conc. increased via G-protein activation of adenylate cyclase  Note: “First messengers” = epi + norepi., calcitonin, PTH, etc ◦ Low Conc. of cAMP = less activity ◦ Decreased via activation of phosphodiesterase  Note: epi and norepi. 1. 2. 3. 4. 5. 6. 7. 8. What is meant by synergistic vs antagonistic, and provide examples of hormone pairs that match those terms? What are the primary roles of and the endocrine roles of the kidney? Intestines? Heart? Thymus? What are gonads? What hormone(s) do testes primarily release & its function? What about the hormones of the ovaries? What is General Adaptive Syndrome, the 3 phases, and main points & hormone for each phase? What hormones tend to be bound, and where are the receptors they bind to located? What are free hormones vs bound? Which are long/short-lived? Which bind extracellular/intracellular receptors? How are first and second messengers related & what is the intermediate that links them? What “type of hormones” act as first messengers? When the G-protein activates adenylate cyclase, how will the cell respond? How about activation of PDE? How do steroid hormones function and the cellular response? How does thyroid hormone function and its effects on the cell?