Module 1 Flashcards
Hormones of neurohypophysis
Arginine vasopressin
Oxytocin
Their binding proteins is
neurophysins
The binding proteins for oxytocin is designated
neurophysin I
and that for AVP is
designated
neurophysin II.
The hormone-neurophysin complex function is ?
It stabilizes the hormone within the neurosecretory granules.
these proteins are glycosylated and packaged as neurosecretory granules in what organ ?
Golgi
The prohormonecontaining granules are transported down the long neuronal axons to their terminals in the
Pars nervosa
Release of the hormone and neurophysin from neurosecretory granules is initiated by ?
from sensory receptors monitoring the osmolarity of extracellular fluid
Electrochemical signals
Hydration of the body or injection of saline solution
into the blood going to the hypothalamus inhibits
release of AVP, leading to ?
resorption of less water
from the glomerular filtrate. Excess water is excreted
from the body as diluted urine.
Dehydration or injection of hypertonic electrolyte
solutions into the hypothalamus stimulates release of
AVP, causing
increased water resorption in the distal
tubules and decreased glomerular filtration, resulting
in less urine being produced.
It is transported by blood to the kidney, where it binds to specific receptors in the distal part
of the nephron and collecting ducts?
Vasopressin
The major effect of AVP
Is to increase resorption of water from the
glomerular filtrate.
The AVP-receptor complex activates ? resulting in increased levels of
cyclic AMP.
Adenylate cyclase
It activates protein kinases and increases phosphorylation of proteins in cells of the
renal distal tubules
Cyclic AMP
It is stored as
neurosecretory granules and is released
from axonal terminals by calcium dependent exocytosis.
oxytocin
