Endocrinology (1) Flashcards

proof of hormones the system process of Renin-angiotensin-aldosterone system function of angiotensin II inhibitors hormonal system hormone family and its interaction with receptor measuring levels of hormones secretion of hormones regulation of systems

1
Q

secretin - discovered

A

by William Bayliss and Ernest Starling

1st hormone

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2
Q

secretin tested - neuronal

A

isolate gut from nervous system by cutting nerves to gut and add acid to duodenum = there was secretion
therefore not neuronal

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3
Q

secretin tested - chemical and results

A

stop blood flow from gut to general circulation and repeat with acid = no secretion
therefore acid on intestines release agent - carried to pancreas through circulatory system
isolate agent and purify = secretin

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4
Q

endocrine system - function and uses

A

group of cells releasing signal into circulatory system at low conc
carried around the body to target
manipulating system/modifying intracellular signalling pathways

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5
Q

main regulators for homeostasis

A

endocrine, parasympathetic and sympathetic nervous systems

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6
Q

field in pharmacology

A

regulate blood pressure, cell growth, cancer studies, diabetes or control blood sugar and ion levels

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7
Q

example of pharmacology

A

Renin-angiotensin-aldosterone system

reducing blood pressure

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8
Q

renin-angiotensin-aldosterone system to increase BP

A

decrease in blood pressure = decrease in flow of fluid through tubule to kidney allow cells to absorb
low in sodium due to absorption back into body monitored by glomerulus - juxtaglomerulus system
decrease in BP = decrease in sodium

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9
Q

renin-angiotensin-aldosterone system - renin

A

cleaves angiotensin = angiotensin 1 - carried in blood to capillaries in kidney and lung
cleaved by enzyme ACE = angiotensin 2 - active hormone

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10
Q

renin

A

enzyme released in kidney induced by 2 things acting together in juxtaglomerular

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11
Q

function of angiotensin

A
affects brain
bind to receptors in kidney
regulate adrenal cortex of adrenal cortex of adrenal gland
cause vasoconstriction of BV
regulate production of ADH
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12
Q

affecting the brain

for angiotensin

A

nerve regulation - sympathetic activity increases

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13
Q

receptor binding - angiotensin

A

in tubule - increase NaCl absorption and excretion of K - not 1:1 - NaCl absorbed more = ionic imbalance - transfer of water with NaCl and absorb water

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14
Q

regulate adrenal cortex of adrenal gland - angiotensin

A

releases aldosterone

potentiates absorption of NaCl and loss of K

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15
Q

regulate production of ADH

A

vasoconstriction and affect collecting ducts part of kidney - allow pores to be put in

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16
Q

inhibitors - stop activity to decrease BP

A
renin 
ACE
angiotensin 2 receptor
aldosterone 
ADH
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17
Q

renin inhibitor

A

prevent digestion of angiotensinogen

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18
Q

ACE inhibitor

A

prevent cleavage of angiotensin 1

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19
Q

angiotensin 2 receptor inhibitor

A

prevent angiotensin 2 binding

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20
Q

aldosterone inhibitor

A

prevent aldosterone binding to receptor

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21
Q

ADH inhibitor

A

decrease BP - prevent water absorption and arteriolar vasoconstriction

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22
Q

receptor in hormonal system

A

highly specific

some have more receptors and some receptors bind to more than one hormone

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23
Q

hormonal - low Kd

A

high affinity

hormone released into whole blood system

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24
Q

Kd

A

how strongly they bind

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25
Q

to have effect in hormonal system

A

lots of integrated amplification at level of cell with receptor

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26
Q

protected transfer system

A

hormone bound to carrier protein

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27
Q

free hormones

A

bind to receptor - H-CPr must dissociate = H + CPr

hormone action continue for longer and regulate amount of free hormone

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28
Q

overall effectiveness depend on

A

conc of affinity of free hormone
no. receptor present on cell
efficiency of amplification
stop signalling - removed

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29
Q

3 main hormone family

A

Amine-derived
peptide
lipid and phospholipid

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30
Q

Amine-derived hormones

A

take off COOH from tyrosine and tryptophan decarboxylated = amine
e.g. catecholamines and thyroxine

31
Q

peptide hormone

A

small TRH (3 a.a) and ADH/vasopressin 9a.a
protein hormone - insulin and growth hormone
glycoprotein hormones - luteinising, TSH - glycosylated

32
Q

lipid and phospholipid hormone

A

eicosanoids (prostaglandin etc) - in immune system and BV regulation and clotting
steroids - derived from cholesterol
calcitriol (vit.D) - sterol derived hormone, no metabolic pathway - cant produce from scratch

33
Q

solubility amine-derived and peptide hormones

A

water soluble - go to receptor will sit at specific phase

34
Q

hormone-receptor interaction

A

H released from CPr and bind to receptor = hormone receptor complex

35
Q

interaction

A
defined by Kd
1:1 reaction
stronger 
v. specific and Kd reange from 10(-9) to 10(-12) molar
reversible
36
Q

interaction - 1:1 reaction

A

[H][R] / [HR]

37
Q

interaction - stronger

A

more in HR state - smaller ratio

free:bound

38
Q

HR

A

hormone-receptor

39
Q

interaction - reversible

A

measure of affinity - ease of separation Kd

40
Q

Kd

A

[H]

half of all R are bound - [R] = [HR]

41
Q

max biological response

A

B max
most have hormone efficiency far lower than what is seen when all R or bound
Kd at 50% level

42
Q

example of max response - insulin

A

bind on adipocytes = uptake metabolites - occur at max level at 2-3% receptor bound

43
Q

amplification downstream signalling system

A

[H] need for max response
sensitivity of system
limiting step in hormonal system - H bind to R - amplification - efficient
driven by secondary messenger/ downstream phosphorylation cascade

44
Q

[H] seen by target cell depend on

A

rate of release
rate of delivery
rate of degradation and elimination

45
Q

rate of release

A

depend on synthesis and selection of H

highly regulated of endocrine control by +ve and -ve feedback loop

46
Q

rate of delivery

A

blood flow to organ(faster) - increase chance of HR complex

carriers - bring H - stop being broken down

47
Q

rate of degradation and eliminating

A

H-characteristic rate of decay-metabolised and excreted

e. g. adrenaline - shutting off secretion H with short half life - decrease rapidly
e. g. thyroid hormone - H’s long biological half life - effective conc persist

48
Q

ways to measure levels of H

A

radioimmune assay

elisa

49
Q

radioimmune assay - process

A

need Ab against H and isolate H radiolabelled = complex and precipitate out radioactive H
complex with sample of unlabelled H down with it
compare known and unknown conc = amount of H/ molecule - present

50
Q

Ab

A

antibodies

51
Q

Elisa - needs 2 antibodies - process

A

plastic surface - capture Ab and H and second Ab bind at another site = amplification system
enzyme links to first detected Ab against detecting Ab
which build pyramid - enzyme attach = S. oxidised and change colour

52
Q

endocrine system - where receptor are sitting on cell - types

A

hydrophilic

hydrophobic

53
Q

hydrophilic receptors in endocrine system

A

ion channel linked

enzyme and G protein linked (need carrier) which have second messenger

54
Q

hydrophobic receptor in endocrine system

plus example

A

cytoplasmic - no second messenger
able to move through membrane and bind to R
= turn off effect/ be carried to R to target area
e.g. thyroid - gets carried into nucleus - drives mRNA expression

55
Q

where hormones are secreted from - 2 type

A

primary endocrine organ
secondary endocrine organ
both secrete H

56
Q

primary endocrine organ example

A

pancreas, parathyroid H, Pit. etc

57
Q

secondary endocrine organ + example

A

secrete H as secondary function

e.g. heart, stomach, liver, kidney, small intestine, skin, ovaries and testes etc

58
Q

pheromone

A

ectohormone - signalling molecules released into environment

59
Q

adipocytes

A

endocrine hormone

make lectin

60
Q

bone - as endocrine organ have examples

A

e.g. thymus, muscle etc

61
Q

endocrine(ductless) gland derive from epithelia

A

adrenal cortex and beta cells

62
Q

endocrine(ductless) gland derive from neurons

A

neurohormones

63
Q

endocrine(ductless) gland derive from isolated cells

A

diffuse endocrine cells- intestines

gut, heart etc

64
Q

immune cell - cytokine function

A

active at low conc and carried in blood

65
Q

controlling endocrine system - simple feedback loop e.g. “A”

A
"A" changes conc 
gland responds to conc 
hormone released
bind to target cells - respond by releasing/absorbing A
repeat
66
Q

examples of the simple feed back loop

A

intestinal H, secretin, Gastrin, CCK insulin, Glucagon-paired

67
Q

beta cells monitor glucose levels - feedback loop

A

glucagon (alpha cell) - increase blood sugar - breakdown glucagon
insulin (beta cell) - decrease blood sugar - absorb glucose

68
Q

regulating extracellular [Ca2+] - 2 hormones used

A
calcitonin - produced by C cells - between follicles in thyroids
parathyroid H (pH) by parathyroid - surface of thyroid
69
Q

regulating extracellular [Ca2+] process when decrease in [Ca2+]

A

parathyroid become excited - release pH into blood

pH bind on osteocyte and osteoclast - break down bone

70
Q

regulating extracellular [Ca2+] process (1) in late distal tubule

A

matrix = Ca2+ - bind on kidney tubule - increase uptake of Ca
activated=s kidney - 1,2-DiOH cholecalciferol = decrease Ca secretion and increase its absorption

71
Q

change in [Ca2+] monitored by

A

C cells - release calcitonin - decrease [Ca2+]

72
Q

hyperparathyroidism - disease

A

too much
primary - more bone breakdown = demineralised
calcification and stone formation
secondary - renal failure - decrease in Ca2+ by kidney - increase parathyroid activity

73
Q

hypoparathyroidism - disease

A

too little
autoimmune
Ab made against parathyroid gland
increase action potential in tissue and heart
decreases inhibition of voltage gated Ca2+ channel