Lec 2 Flashcards
other name for pituitary
hypophysis
name for posterior pit gland
neurohypophysis
what hormones does neurohypophysis release
ADH and oxytocin
what are the neurons in ant hypothalamus called
magnocellular neurons
where do magnocellular neurons travel to
supraoptic-hypothalamic tract
down to post pituitary
in the hypothalamus, what do magnocellular neurons make uP
the supraoptic and paraventricular nuclei
what is released from the supraoptic and paraventricular nuclei
oxytocin and vasopressin
form hypothal to ppg
process of TSH being released from APG
environmental influence -> hypothal releases thyrotopin releasing hormone (TRH) –> APG releases TSH
Tropic = acts on thyroid gland = thryoid hromones
Non tropic = increases metabolism
inc heat production
how does hypothal communicate w APG
hypothalamic-portal blood system
NOT direct nervous connection unlike PPG
name of neurons that lead to APG
parvocellular
in hypothal, what do the parvocellular neurons make up
hypothalamic-hypophyseotrophic nuclei
what do the parvocellular neurons release
releasing hormones
which are released in median eminence
carried to APG
where is the hypothalamic portal blood system
made up of two capillary beds, one in the median eminence and the other in the anterior pituitary.
benefit of the portal blood system
not lots of hormone needed
cuz isnt diluted by blood
precursors to oxytocin and ADH
neurophysins
(synthesised as preprohormones)
then get packaged in secretory granules in SON and PVN
what are herring bodies
where oxytocin and ADH are stored in secretory granules in axonal termina;
orexins other name
hypocretins
what type of hormone is orexin
neuropeptide hormone
where is orexin released from
lateral and posterior hypothalamus
orexin function
- wakefulness, eating
how to experimentally test that chemicals from hypothal are stimulating pit gland
- put APG cells in soln
- ACTH released from these
but will run out - add fresh hypothalamic tissue
- APG cells will start releasing ACTH again
where are corticotropic cells
in APG
corticotropic cells function
releases adrenocorticotropic hromone (ACTH) which
stimulate adrenal cortex
what does adrenal cortex release
glucocorticocoids
how is the ACTH system regulated
glucocorticoids neg inhib corticotopes
what connects hypothal and pit
infundibular stalk
experiment on dog when infundibular stalk seperated: results
- weight gain
- dystrophia adiposo-genitalis
- genital and mammary atrophy
- APG atrophy
(these things can be seen in humans if the stalk is compressed by a tumour for exmaple
