Chapter 20 - Pituitary Flashcards
What does the hypothalamus release?
TRH, CRH, GnRH, GHRH, dopamine into median eminence
What is the path of hormones released from the hypothalamus?
Median eminence, passes through neurohypophysis on way to adenohypophysis
What is the action of dopamine on prolactin?
Inhibits prolactin secretion (bromocriptine analog)
What does the posterior pituitary (neurohypophysis) release?
ADH and oxytocin
What part of the hypothalamus does ADH come from? Regulation?
Supraoptic nuclei; regulated by osmolar receptors in hypothalamus
What part of the hypothalamus does oxytocin come from?
Paraventricular nuclei
What does the anterior pituitary (adenohypophysis) secrete?
FSH, LH, ACTH, TSH, prolactin, GH
Blood supply of the anterior pituitary?
Does not have its own blood supply; passes through neurohypophysis 1st
What is bitemporal hemianopia caused by?
Pituitary mass compressiong the optic nerve at chiasm
How do nonfunctional pituitary tumors present?
Almost always macroadenomas; present with mass effect and decreased ACTH, TSH, GH, LH, FSH
Treatment for nonfunctional pituitary tumors?
Transsphenoid resection
What are the contraindications to transsphenoidal resection?
Suprasellar extension, massive lateral extension, dumbbell-shaped tumor
Medical treatment for TSH- and FSH-/LH-secreting tumors?
Bromocriptine
What is the most common pituitary adenoma?
Prolactinoma
Size of most prolactinomas (micro or macro)?
Microadenomas