hypothalamo-pituitary axis

Question 1

describe the location of the hypothalamic nuclei

Answer 1

top to bottom, front to back

paraventricular
anterior
supraoptic

dorsomedial
ventromedial
arcuate

posterior
mamillary body (brain boob)

Question 2

what regulates GNRH

Answer 2

kisspeptin

Question 3

what does gnrh regulate

Answer 3

fsh and lh

Question 4

what does adh have to do with acth

Answer 4

adh stimulates acth via short portal vessels between posterior and anterior pituitary

Question 5

50% of pituitary gland cells are

Answer 5

GH cells

Question 6

what does GH make

Answer 6

IGF-1

Question 7

what inhibits prolactin

Answer 7

dopamine

Question 8

what is prolactin stimulated by and when would you see hyperprolactinemia

Answer 8

TRH
hypothyroidism

Question 9

what stimulated ACTH (2)

Answer 9

CRH, ADH via porrtal system

Question 10

GH release is what style

Answer 10

pulsatile

Question 11

what unexpected hormone stimulates GH

Answer 11

ghrelin

Question 12

child with dwarfism and cretinism probably what mutation

Answer 12

PIT-1

Question 13

gh released from what sort of cells

Answer 13

somatotroph

Question 14

McCune Albright syndrome explain pathophysiology

Answer 14

oncogenic mutation in GNAS gene means alpha subunit in the GHRH receptor retains its activation->CAMP downstream function but LOSES its ATPase function so it no longer self-regulates and is always activated

Question 15

what sort of receptors are endocrine receptors normally

Answer 15

GPCR

Question 16

why do you only see eg mccune albright in mosaic form

Answer 16

germline mutation would not be compatible with life

Question 17

how many giants have recognised genetic element

Answer 17

50%

Question 18

GH receptor is not a GPCR - what is it

Answer 18

dimerised cytokine receptor

Question 19

IGF is secreted by many tissues but where is the one that can be measured int he blood stream made

Answer 19

liver

Question 20

what’s the relevance of GPR101

Answer 20

mutation prevalent in gigantism. related to GHRH stimulation but not sure how

Question 21

how do you recognise Addison’s pt just by looking at them

Answer 21

hyperpigmentation

Question 22

what is is ACTH made from

Answer 22

POMC

Question 23

if POMC is high and ACTH is therefore high, what subunit of ACTH will also be high and what will be the result

Answer 23

alpha MSH
hyper pigmenttation( Addison’s disease)

Question 24

red hair and fair skin

Answer 24

MC-1r variant

Question 25

cortisol is… in teh morning and …at night

Answer 25

high
undetectable

Question 26

when Cushing’s disease

Answer 26

pituitary tumour secreting ACTH only

Question 27

when would you need petrosal sinus/venous sampling

Answer 27

distinguish where excess ACTH is coming from in cushings disease. Eg lung tumour or overactive pituitary

Question 28

glucocorticoid +++intake leads to

Answer 28

iatrogenic cushings

Question 29

if you provide steroid tx for a pt, always give them…

Answer 29

steroid card

Question 30

which four glycoprotein hormones have the same alpha unit but different beta units

Answer 30

LH, FSH, TSH, HCG

Question 31

how do you stop FSH and LH in the case of breast/prostate cancer

how on earth does it work

Answer 31

give GNRH analogue.

Too much “GNRH” overwhelms the GPCR so it becomes desensitised and stops workign

Question 32

FSH and LH are released by GNRH from the same cell so how can they be different levels at different times?

Answer 32

pulsatility. If GNRH every hour, LH high, FSH low

If GNRH every three hours, other way round

Question 33

Kallmann syndrome

Answer 33

can’t smell, don’t go through puberty

Question 34

what is copeptin

Answer 34

like peptide C of adh precursor. can be measured

Question 35

what is new name for diabetes insipidus

Answer 35

AVP deficiency