Tidbits from lecture notes Flashcards
Oxytocin released from the posterior pituitary is created in the ____ of the hypothalamus.
Paraventricular
ADH released from the posterior pituitary is created in the ____ of the hypothalamus.
Supraoptic
PTH is secreted by?
Chief cells of the parathyroid glands.
What is Laron’s dwarfism?
Larons dwarfism is a lack of response to GH. GH levels are normal, but decreased receptor function causes. REgular dwarfism is caused by low GH.
What two things increase GHRH release in the hypothalamus? What two things block its release?
Hypoglycemia and amino acids increase release of GHRH.
Somatostatin and GH block release of GHRH.
What two things are necessary for IGF formation?
Insulin and growth hormone.
INcreased PRL decreases levels of _____.
GnRH
What is sheehans syndrome?
Destruction of the pituitary during birth. Presents as a failure to lactate postpartum.
Growth hormone is released from _____ (cell type), and signals through a _____ pathway.
somatotrophs in the anterior pituitary
JAK/STAT pathway
What effect do estrogen and progesterone have on mammogenesis, lactogenesis, and galactopoiesis?
They are inhibitory to lactogenesis and galactopiesis.
They encourage mammogenesis.
Why? Placenta makes both. Don’t want to start lactating until after birth. So, after birth, levels drop and milk lets down.
What is the effect of estrogen/progesterone on prolactin levels?
They are antagonistic to PRL. PRL is mammogenic, galactogenic, and lactogenic.
Which releasing hormone is pulsatile in nature?
GHRH
What does the anterior pituitary release?
ACTH GH FSH LH PRL TSH
What does the hypothalamus release onto the anterior pituitary?
Thyrotropin releasing hormone (TRH)
Gonadotropin releasing hormone (GnRH)
Corticotropin releasing hormone (CRH)
Growth hormone releasing factor (GHRH)
Somatostatin (GH inhibiting hormone; GIH)
Prolactin inhibiting factor (PIH aka DOPamine)
The two inhibitory hormones act through Gi signalling, the stimulatory hormones (released by the hypothalamus) act through Gs, with the exception of one, which acts through Gq. Which?
GnRH—Gq—> gonadotrophs—> FSH/LH
