Hormones Of neurohypophysis Flashcards
Hormones of neurohypophysis
Arginine Vasopressin and Oxytocin
The primary stimuli for
oxytocin release from storage sites in
the neurohypophysis are:
- distention of the reproductive tract,
particularly in the pregnant female - stimulation of the mammary gland by
the young - audiovisual contact with the
offspring
It has specific effects on contraction of smooth muscle of the uterus and cells of the mammary
Oxytocin
oxytocin is used for ?
inducing parturition in some species, or
to increase uterine
contraction at parturition, and
for the treatment of retained placenta, metritis, and in some cases agalactia
oxytocin is stored as
? and is released
from axonal terminals by calciumdependent exocytosis.
Neurosecretory granules
Vasopressin is transported by blood to the
Kidney
The major effect of AVP is to
increase resorption of water from the
glomerular filtrate.
The AVP-receptor complex activates what ? resulting in increased levels of
cyclic AMP.
adenylate cyclase
The hormone-neurophysin complex is
stabilizes the hormone within the neurosecretory granules
Release of the hormone and neurophysin from neurosecretory granules is initiated by
electrical signals
binding proteins for oxytocin is designated
Neurophysin I
for AVP is
Neurophysin II
The hormones secreted by
cells in these hypothalamic nuclei in most mammalian species are
oxytocin and arginine vasopressin
these proteins are glycosylated and packaged as neurosecretory granules in
Golgi App
Cell bodies of the neurons producing AVP and oxytocin are located in
paraventricular and
supraoptic nuclei at the base of the hypothalamus
