pituitary disorders

Question 1

is the posterior pituitary a endocrine gland

Answer 1

not an endocrine gland: simply stores and releases

has a neuro component

Question 2

most disorders result from dysfunction in?

Answer 2

anterior pituitary (TSH and ACth released)

Question 3

hyperfunction of anterior pituitary=

Answer 3

adenomas- benign tumor forming in a gland—> cause trophic stimulation (eg tumor secreting acth and causing increased cortisol release in cushings)

Question 4

posterior pituitary receives hormones that are produced in the …

Answer 4

hypothalamus

Question 5

SIADH=

Answer 5

syndrome of inappropriate ADH secretion

-hypersecretion of ADH

Question 6

ADH opposes…

Answer 6

diuresis (retains fluids and sodium follows!)

Question 7

failure of…

Answer 7

negative feedback. excess ADH does not result in suppression of hypothalamus or posterior pituitary

Question 8

etiology/ explanation of SIADH?

Answer 8

• ectopic tumors (ex in lung) secrete ADH like substances that produce same effect
• hypervolemia d/t increased H20 and Na retention
• water retention: dilutional hyponatremia (although some Na+ retainer, more water retained, dilutes conc of sodium)
• renin and aldosterone secretion is suppressed because RAAS is only triggered w hypovolemia—> impaired Na+ reabsorption (further hyponatremia

Question 9

treatment for SIADH?

Answer 9

restrict fluids if mild
diuretics ---> aquaretic= electrolyte sparing diuretic
ADH antagonists (oppose action of ADH, ex binding to ADH receptor site)