Endocrinology and growth

Question 1

where does ADH mainly work

Answer 1

collecting ducts

Question 1

Androgen insensitivity presentation and blood results

Answer 1

primary amenorrhoea
high LH
normal FSH
high Oestradiol
high testosterone

men: undescended testes and limited body hair. Under masculinised male

Question 2

McCune Albright syndrome

Answer 2

spontaneous mutation inGNAS 1 gene
2 features of: cafe au lait spots, precocious fuberty, fibrous dysplasia

Question 3

which investigation can help distinguish between ectopic ACTH secretion and excessive pituitary secretion (cushings)

Answer 3

Inferior petrosal sinus sampling
sampling blood from IPS before and after CRH administration and comparing concentration of ACTH with peripheral blood

a ration of > 2:1 at baseline or >3:1 after CRH strongly suggestive of cushings
normal ration: ACTH from ectopic source

Question 4

blood tests in vit D deficiency

Answer 4

low/normal Ca
low phosphate
secondary high ALP and PTH

Question 5

Blood tests in pseudohypoparathyroidism

Answer 5

low Ca
high phosphate
normal ALP
high PTH

Question 6

blood tests in hypoparathyroidism

Answer 6

low Ca
high phosphate
normal ALP
low PTH

Question 7

Vit D resistant rickets

Answer 7

normal Ca
low phosphate
normal or low vit D
secondary high ALP and PTH
urine phosphate high

X linked dominant

Question 8

Atrial Natriuretic peptide

Answer 8

causes systemic vasodilation and dilation of afferent glomerular arteriole and contraction of efferent glomerular arteriole

increases GFR, faster excretion of Na and water which lowers BP

stretching of atrial muscle wall due to vol overload triggers release of ANP