pituitary gland Flashcards
(21 cards)
describe the development of anterior pituitary gland?
oral cavity as RATHKE pouch and to goes up to the brain area
describe the development of posterior pituitary gland?
it is nervous tissue from the brain going downward
what will the cleavage of rathke pouch form in the oral cavity?
depression / dimple that will be adenoid
what connects the neurohypophysis ( posterior pit ) to the neural tissue?
infundibular stem/stalk
what comes from the adenohypophysis (anterior pituitary) and wraps around the infundibular stem?
pars tuberalis wraps around the infundibular stem to form the infundibulum
which gland will have dark staining and which one will have lighter staining?
dark staining = adenohypophysis = anterior pituitary
light staining = neurohypophysis = posterior pituitary
posterior pituitary is also formed of pars nervosa which will be lighter due to the axons going to it
what are the type of cells found in anterior pituitary?
chromophils –> take up stain —> Acidophils and basophils
chromophobes —> doesnt up the stain
what are the acidophilic cells ?
somatotrophs —-> Secrete GH and represent 50% of the ant pit cells
lactotrophs —–> secrete prolactin and represent 10-15% of ant pit cells
what are the basophilic cells?
corticotrophs —> secrete ACTH and represent 15-20% of ant pit
thyrotrophs ——-> secrete TSH and represent 10% of ant pit cells
Gonadotrophs —–> secrete LH and FSH and represent 10-25% of ant pit cells
how do we differentiate between acidophils and basophils ?
we have to use special stain like immunohistochemical stains
how do you differentiate between the layers of anterior pituitary ?
area of dark staining followed by space —> pars distalis
dark staining after the space —-> pars intermedia
light stained area after pars intermedia —-> pars nervosa ( post pit )
dark stained area surrounding light stained area —> pars tuberalis surrounding the inf. stem
the space between then –> hypophyseal cleft
describe pars intermedia?
poorly developed in humans
separated from pars distalis by hypophyseal cleft
contain colloid filled vesicles ( FOLLICULAR IN SHAPE )
where do the colloid vesicles present in pars intermedia come from?
remnants of rathke pouch
what hormone does the pars intermedia release?
melanocyte stimulating hormone
what are the components of pars tuberalis?
contain cords of epithelial cells
filled with hypophyseal portal vessels
Contain acidophil and basophil cell
wrap around the inf. stem to form infundibulum
what are the components of posterior pituitary ?
unmylelinated axons ————> LONG cells
Capillaries where the hormone release happen
Glial cells/ pituicytes ——-> circular nucleus shape , SUPPORTING CELLS
from which nucleus does these axons come from?
paraventricular —–> oxytocin
supraoptic —-> ADH
where do the axons end?
herring bodies —> neurosecretory granules
what would an adenoma of acidophils result to?
in kids —-> gigantism cuz too much GH from acidophils
in adults —> acromegaly —> too much GH from acidophils
what would an adenoma of basophils result to?
Cushing syndrome —> excess of ACTH
Hyperthyroidism —> excessive of TSH
what are the features of cushing syndrome ?
mooning of face , fat deposition , in the neck and trunk
