Endo 2 Flashcards
Is the anterior pituitary gland a true endocrine organ?
yes
is the posterior pituitary gland a true endocrine organ?
no
-contains axon terminals of hypothalamic neurons
Where is the pituitary gland located?
in the sella turcica
What hormones are released from the anterior pituitary?
growth hormone
ACTH
TSH
FSH
LH
prolactin
What hormones are released from posterior pituitary?
ADH/vasopressin
oxytocin
What type of cells secrete GH?
somatotrophs
What type of cells secrete ACTH?
corticotrophs
What type of cells secrete TSH?
thyrotrophs
What type of cells secrete LH nad FSH?
gonadotrophs
What type of cells secrete prolactin?
mammotrophs
Where are hypothalamic hormones released into?
primary capillary plexus in the median eminence
What carries the hypothalamic hormones to the sinuses of the anterior pituitaryt?
hypothalamic-hypophyseal portal blood vessels
How does GH function?
it can act directly on the tissue or act as a tropic hormone to the liver
-causes the release of insulin like growth factor in the liver
How is GH released?
in a pulsatile manner
-lower during the day with highest levels a few hours after sleep
What stimulates the release of GH?
starvation, fasting, stress, exercise, and excitement
How does the secretion of GH change throughout life?
-high during neonatal period
-decreases in childhood
-peaks during puberty
-declines with age after puberty
Where is IGF-1 made?
in most tissues and act as a neighboring cells in a paracrine manner
-major site of synthesis is in the liver