Intro to endocrine

Question 1

give an example of a slow response and fast response hormone.

Answer 1

slow response i.e. increase in protein synthesis in response to growth hormone
fast response i.e. increased heart rate in response to adrenaline

Question 2

what is a neurohormone?

Answer 2

a hormone that is released from a nerve into the blood stream, to act on their target cell

Question 3

what is glycogenesis?

Answer 3

the conversion of glucose into stored glycogen in the liver

Question 4

wha is gluconeogenesis?

Answer 4

the conversion of non-glucose substances into glucose i.e. glycerol from adipose tissue

Question 5

do endocrine hormones exert their effects at low or high concentrations? and what is this concentration range?

Answer 5

very low concentrations (you need relatively low concentrations of hormone to make an effect)
=> 10(-9) - 10(-12)

Question 6

where are peptide, amine and steroid hormones derived from?

Answer 6

peptide = chains of amino acids
amine = either tyrosine or tryptophan amino acids 
steroid = cholesterol

Question 7

name 3 peptide hormones.

Answer 7

TRH (thyrotrophin releasing hormone)
FSH (follicle stimulating hormone)
Insulin

Question 8

where are peptide hormones stored until they are released into the blood stream?

Answer 8

within vesicles of the golgi apparatus

Question 9

why is it clinically useful to test a diabetics inactive form of insulin (C-protein) in the plasma instead of just measuring insulin directly?

Answer 9

the levels of the inactive form reflects the insulin that is produced from the pancreas and so the levels of C-protein aren’t affected by the synthetic insulin administered

Question 10

what hormones are water soluble/hydrophillic? and does this mean they can cross the cell membrane or not?

Answer 10

peptide and amine hormones (catecholamines not thyroid hormones)
they cannot cross the membrane
this is why their receptors are on the outside of the cell

Question 11

what hormones are lipophilic?

Answer 11

steroid hormones
amine hormones (thyroid hormones)

Question 12

what are the 2 sub types of amine hormones?

Answer 12

catecholamines;
- dopamine
- norepinephrine 
- epinephrine 
thyroid hormones;
- thyroxine 
- triiodothyronine

Question 13

what amino acids are the amine hormones derived from?

Answer 13

all are derived from tyrosine except melatonin - tryptophan

Question 14

what hormones are synthesised as needed as opposed to being synthesised and stored?

Answer 14

steroid hormones

Question 15

what increases the half life of steroid hormones?

Answer 15

they are bound to carrier proteins i.e. albumin

Question 16

how does steroid hormones alter protein synthesis?

Answer 16

steroid hormones enter the cell
they trigger the activation or repression of gene function within the nucleus
and because genes regulate the synthesis of proteins, these hormones ultimately inhibit or increase protein synthesis

Question 17

what are 4 places where steroid hormones are produced?

Answer 17

gonads (sex hormones)
placenta (hCG, sex steroids)
kidney (vitamin D3)
adrenal cortex (corticosteroids)

Question 18

what are the catecholamine hormones and which ones are neurohormones and endocrine hormones?

Answer 18

dopamine (neurohormone)
norepinephrine (neurohormone)
epinephrine (endocrine hormone)

Question 19

what are the thyroid hormones (amine)?

Answer 19

thyroxine

triiodothyronine

Question 20

what hormones have a short half life and what ones have a long half life?

Answer 20

peptide and catecholamines = short

thyroid and steroid = long

Question 21

the presence of one hormone enhances the effect of another.

what is this an example of?

Answer 21

permissive effects

Question 22

what hormone acts in an antagonist way and how?

Answer 22

growth hormone

it impairs the tissues response to insulin by decreasing the number of insulin receptors on tissues

Question 23

why is 24 hour monitoring of hormone levels required instead of single readings?

Answer 23

hormone concentration varies widely because hormones are released in short bursts
and only small amounts of hormone are required for effects