B6-064 Growth Hormone/Prolactin Flashcards
the arcuate nucleus in the hypothalmus secretes what in the GH pathway?
growth hormone releasing hormone (GHRH)
secondary triggers for the release of GHRH [4]
increased amino acid levels
hypoglycemia
decreased fatty acids in blood
exercise
GHRH goes into the […] to stimulate somatotropes to secrete GH
adenohypophysis
GHRH goes into the adenohypophysis to stimulate […] to secrete GH
somatotropes
GHRH goes into the adenohypophysis to stimulate somatotropes to secrete […] into the blood
growth hormone (GH)
how does GH stimulates the production of IGF type 1
- some GH binds to tyrosine kinase-like receptor
- stimulates JAK/STAT activation
- STAT goes into the nucleus and stimulates the production of IGF1 (insulin growth factor 1)
some GH stimulates […] in the liver
gluconeogenesis
how does GH trigger lipolysis
GH binds to hormone sensitive lipase
HSL initiates lipolysis –> more glycerol available for gluconeogenesis
[…] stimulates amino acid uptake
GH via IGF1
**activate channels for amino acids on skeletal cell membranes
stimulates amino acids to link together to produce myofibrils –> hypertrophy
IGF1
regulates osteoblasts and osteoclasts to encourage appositional growth and endochondral ossification of bones
IGF1
IGF1 stimulates the production of […], which is crucial to endochondral ossification
collagen type 1
stimulates chondroblasts to differentiate, increase in size, and proliferate resulting in interstitial growth
IGF1
modified apocrine glands designed to produce milk
mammary glands
simulates the production of milk by alveolar cells
prolactin
tube-like structures made up of alveolar glands
lobules
anchor the breast to the posterior wall
suspensory ligaments
little tubes that drain the lobules
lactiferous ducts
dilation of lactiferous duct just behind the nipple
lactiferous sinuses
prolactin is synthesized by […] in the anterior pituitary
lactotropes
prolactin is synthesized by lactotropes in the […]
anterior pituitary
prolactin inhibiting hormone (dopamine) are secreted by the
hypothalamus
**go through hyophyseal portal system to anterior pituitary
binds to D2 receptors to inhibit lactotropes
prolactin inhibiting hormone
[dopamine]
thyrotropin-releasing hormone (TRH) is secreted by the […] nucleus
paraventricular nucleus
binds to specific receptors to stimulate prolactin secretion via lactotropes
thyrotropin-releasing hormone (TRH)
how does breast feeding provide a direct stimulus of prolactin? [2]
baby suckling triggers mechanoreceptors to release oxytocin –> stimulates production of prolactin
baby sucking stimulates PVN to release more TRH –> stimulates lactotropes to produce prolactin
high levels of […] are extremely important to prolactin stimulation
estrogen
estrogen stimulates the production of prolactin directly via the […] and indirectly by […]
direct: via the lactotropes
indirect: inhibits the arcuate nucleus from secreting PIH (dopamine)