1 - Hypothalamus / Posterior Pituitary

Question 1

blood supply to hypothal/ pituitaries

Answer 1

branches of internal carotid:
superior hypophyseal artery > hypothal and antPit
middle and inferior hypophyseal arteries > postPit and pituitary stalk

Question 2

hunger and satiety hormones

Answer 2

ghrelin and leptin

Question 3

sx of hypothalamic lesions

Answer 3

disuption of appetite > obesity/anorexia
disturbed sleep/wake cycles
fever/hypothermia
panhypopituitarism
DI
emotional lability, apathy, memory loss

Question 4

Kallmann’s syndrome

Answer 4

XL - KAL gene mutation
isolated hypogonadotropic hypogonadism w/ anosmia
due to abnl migration of olfactory and GnRH neurons during development

Question 5

anorexia nervosa and the hypothal

Answer 5

disordered hypothal w/o identifiable anatomical defect
wt loss / appetite dysregulation
hypothalamic amenorrhea
low TSH, T3, T4
normal to high GH, but low IGF-1

Question 6

where are oxytocin and vasopressin made?

Answer 6

paraventricular and supraoptic nuclei

Question 7

2 stimuli that cause vasopressin release, which is used more often?

Answer 7

osmotic increase (more commonly used)
BP drop (significant, not very often)

Question 8

changes in water balance following pituitary stalk damage

Answer 8

triphasic response:
~4d of DI, little to no ADH secreted
then a period of normal urine output as ADH is released from damaged neurons
then can turn into permanent damage w/ dec or no ADH output

Question 9

2 common causes of nephrogenic DI

Answer 9

hypokalemia

hypercalcemia

Question 10

difference btwn complete and partial central DI in water deprivation test results

Answer 10

complete will have urine osm < serum osm and urine osm 50% inc in urine osm

partial will have urine osm >= serum osm and urine osm of around 300-400 and DDAVP will only inc urine osm by 10-50%

Question 11

tx of DI

Answer 11

central - DDAVP

nephrogenic - tx underlying cause, thiazides, NSAIDs