Pituitary gland Flashcards
(26 cards)
how does negative feedback work
as a hormone increases in conc it inhibits the release of another hormone
how many hormones does the anterior pituitary gland release
7
what are the 7 hormones the anterior pituitary release
FSH LH ACTH GH TSH Prolactin Melanocyte stimulating hormone
what hormones does the posterior pituitary release
ADH
OXYTOCIN
blood supply to the anterior pituitary
none
receives blood supply through a portal venous system from hypothalamus
what is the hypothalamus
collection of brain nuclei
connects to almost all other areas of brain
important for homesotasis
control of endocrine function via pituitary
what hormones does the hypothalamus release
thyrotropin releasing hormone TRH
corticotropin releasing hormone CRH
gondatropin releasing hormone
dopamine
when is GH released
by low glucose
exercise
sleep
action of growth hormone
linear growth in children
acquisition of hormone
stimulates protein synthesis . lipolysis
psychological well being
what is prolactin used for
stimulates the production of breast milk
what is the HPA axis for
in response to stress hypothalamic pituitary axis
to release cortisol
how does the HPA AXIS WORK
Hypothalamus releases CRH-
Causes the ant pituitary to release ACTH to act on adrenal gland
adrenal releases cortisol from zona fasiculata
too much cortisol inhibits acth thus allowing for negative feedback
what is crh
corticotropin releasing hormone
what is acth
adrenocorticotropic hormone
what is the HPS or Insulin growth factor for
regulates the growth and development of childrn
how does the HPS axis work
hypothalamus releases GHRH +ve and somastatin -ve
causes ant pituitary to release GH
GH acts on the liver to make insulin like growth factor
what does insulin like growth factor promote
skeletal growth and bone
density
muscle strength
protein synthesis
Which of the anterior and posterior pituitary produces its own hormones
The anterior pituitary produces and releases its own hormones, under the regulation of hormones made by the hypothalamus
Which layer of the adrenal cortex is responsible for the secretion of cortisol?
zona fasiculata
how does the hpg axis work in men
Hypothalamus releases gnrh
Causes ant pituitary to release FSH and lh
Causes the testes to release testosterone
Negative :
When conc of testosterone in blood is too high then the test inhibits the release of gnrh from hypothalamus and lh ans fsh from ant pituitary
what does hpg axis mean
hypothalamic pituitary gonadatropin releasing hormone axis
what does LH in men do
stimulates leydig cells which causes the testes to release testosterone
how does the HPP axis work
hypothalamus releases TRH in response to baby suckling on boob
this causes ant pit to releases prolactin which causes lactation
too much prolactin in blood then dopamine is released to inhibit prolactin
where is oxytocin synthesised
hypothalamus- paraventricular nucleus
