endocrine

Question 1

in the adrenal gland, cholesterol is converted to pregninolone to 17 OH progesterone. What is it then converted into?

Answer 1

aldosterone, cortisol and androgens

so even though ACTH is mainly to stimulate cortisol production, it also causes increased aldosterone and androgens

21 hydroxylase and 22 hydroxylase are needed for production of aldosterone and cortisol but NOT androgens

Question 2

describe pathophysiology of CAH

Answer 2

21 (or 11) hydroxylase deficient
so 17 OH progesterone cannot become aldosterone or cortisol (which requires 21 or 11 hydroxylase)
so it all becomes androgens
there’s lots of ACTH made made trying to produce cortisol and aldosterone because there’s no negative feedback
so there is hyperplasia of the adrenal glands from all the ACTH

Question 3

describe phenotype in CAH

Answer 3

virilization of female fetus due to excessive androgens (female pseudohermaphrodism / ambiguous external genitalia) (but they have normal internal female organs)
but in a male, the excess androgens are not a big deal for the external genitalia

also, due to aldosterone deficiency, there is low sodium, high potassium
and low BP from cortisol deficiency

Question 4

The rate of growth hormone secretion follows a circadian rhythm. When is the highest peak of growth hormone release?

Answer 4

early sleep