Pituitary histo -Altikriti

Question 1

What is the embryologic origin for the anterior pituitary? posterior pituitary ?

Answer 1

ant pit=Rathke’s pouch=oral ectoderm

post pit=infundibulum=neural ectoderm (diencephalon)

Question 2

What is the path of flow from the hypothalamus to the anterior pituitary?

Answer 2

hypothalamus parvicellular cells (neurosecretory) terminate at the median eminence –> releasing hormones from the hypothalamus–> superior hypophyseal A (off the ICAs) –> primary capillary network of fenestrated capillaries –> portal veins to the secondary capillary plexus in the ant pit–> endocrine cells release hormones into circulation via the hypophyseal veins

hypophyseal portal system

Question 3

What 2 nuclei control the posterior pituitary?

Answer 3

paraventricular nuclei and the supraoptic nuclei

Question 4

What neuroendocrine cells are part of the posterior pituitary?

Answer 4

magnocellular cell axons make up the hypophyseal tract

Question 5

What neuroendocrine cells stimulate the anterior pituitary?

Answer 5

parvicellular—> short axons which terminate in the median eminence to follow blood flow and stimulate hormone production of the anterior pituitary

Question 6

What are the 3 histological components of the neurohypophysis? What do they look like and what are their functions?

Answer 6

1. pituicytes: resembles glial cells, provide support to axons
2. unmyelinated axons: from neuroendocrine cells of the magnocellular neurons of the hypothalamus–> axon terminals are in expanded boutons called “herring bodies” which contain hormones and neurophysin.
3. fenestrated capillaries: from the inferior hypophyseal A–> in close contact with Herring bodies

Question 7

What hormones does the posterior pituitary produce? secrete?

Answer 7

posterior pituitary does NOT produce.

it secretes oxytocin and ADH

Question 8

Which hormone does the SON produce? PVN?

Answer 8

SON==> ADH

PVN==> oxytocin

Question 9

What are the 3 cell types found in the adenohypophysis that are recognized by staining?

Answer 9

1. basophilic=blue
2. acidophilic=pink
3. chromophobes=clear

Question 10

What are the basophilic anterior pituitary hormones? The acidophilic hormones?

Answer 10

basophilic: B FLAT (FSH, LH, ACTH, TSH)
acidophilic: GH and PRL