endocrine embryo and histo (reynolds) Flashcards
what is the “master regulator” of the endocrine system?
hypothalamus
3 actions of the hypothalamus
secretes ADH and oxytocin; directly innervates the adrenal glands; regulates the pituitary gland with hypothalamic-releasing and inhibiting hormones
what type of cells make up the hypothalamus
neurons and glial cells
2 parts of the pituitary gland
infundibulum and rathkes pouch
where does the infundibulum form from?
nervous system (extension of the dicephalon)
where does rathkes pouch form from?
stomodeum (evagination at the stomodeum)
t/f. both the infundubulum and rathkes pouch are mesoderm
false. ectoderm
3 parts of rakes pouch
pars distalis, pars tuberalis, pars intermedius
adenohypophesis
rathkes pouch
neurohypophesis
infundibulum
what makes up the post pituitary?
infundibulum (and median eminence)
what makes up the ant pituitary?
rathkes pouch
major cell types in ant pit
chromophobes and chromophils
examples of chromophils
ACTH, TSH, GH, prolactin, FSH, LH, melanocyte-stimulating hormone (ADH and oxytocin are indirect from hypothalamus)
what is in the 3rd pharyngeal pouch?
inferior parathyroid and thymus
what is in the 4th pharyngeal pouch?
sup parathyroid and ultimupharyngeal body
what is the fate of the ultimopharyngeal body?
becomes parafollicular cells that secrete calcitonin
cell types of the thyroid
follicular cells and parafollicular cells
where are the follicular cells from?
migrate form the foramen secum
where are the parafollicular cells form?
pouch 4
what do follicular cells do
secrete T3 and T4
histology of follicular cells
simple cuboidal
what do parathyroid cells do
secrete calitonin
cretinism
disorder when thyroid fails to develop
how does the parathyroid form?
3rd and 4th pharyngeal pouch
2 parts of the adrenal gland
medulla and cortex
what germ layer does the medulla come from
ectoderm (ANS)
what germ layer does the cortex come from?
mesoderm (gonads)
what type of cells are in the medulla?
chromaffin cells
what do chromaffin cells do?
secrete catecholamines
what does the cortex do?
secrete steroid hormones
t/f. the cortex is made of 4 layers
false. 3 layers
t/f. the pancreas has exocrine and endocrine funciton
true
where does the pancreas form from
1 dorsal pancreatic bud and 2 ventral pancreatic buds off the GI
annular pancreas
a disorder when the buds of the pancreas fail to fuse properly, obstructing the duodenum
major cell type of the pancreas
islets of langerhans
germ layer of islets of langerhans
endoderm
most numerous islet cell
beta
what do alpha islet cells secrete
glucAgon
what do beta islet cells secrete
insulin
what do delta islet cells secrete
somatostatin
what determines an endocrine cell response
receptors of the target cell
where is the hypothalamus located?
base of the brain
where are ADH and oxytocin stored
after neurosecretory cells are produced in the hypothalamus, they are transported through the distal ends of the neurons into the post pituitary and are released in the bloodstream as needed
cell type of parathyroid
chief cells and oxyphil (minor)
what do chief cells do?
make PTH (antagonist to calcitonin)
where does the thymus originate from?
3rd pouch
where is the thyroid?
just below the larynx
what activates the thyroid?
TSH form the ant pit
what do T3 and T4 do?
increase metabolism and helps growth and development; require iodine for synthesis
