Endocrine Cells

Question 1

Name types of acidophiles in anterior pituitary (adenohypophysis), what they secrete, and how they are regulated.

Answer 1

Acidophile: Somatotrophs (secrete GH, stimulated by GHRH and inhibited by somatostatin from hypothalamus), Mammotrophs (secrete prolactin, inhibited by Prolactin inhibiting hormone, aka PIH from hypothalamus)*non-tropic hormones

Question 2

Name types of basophiles in anterior pituitary (adenohypophysis), what they secrete, and how they are regulated.

Answer 2

Corticotrophs: secrete ACTH and stimulated by CRH from hypothalamus.Thyrotrophs: secrete TSH and stimulated by TRH, inhibited by somatostatin.Gonadotrophs: secrete FSH and LH and stimulated by GnRH

Question 3

What are chromophobes?

Answer 3

Cells that account for 50% of what is found in adenohypophysis. Progenitor cells, stem cells, dégranulated cells. Lightly stained.

Question 4

How are hormones in anterior pituitary cells released?

Answer 4

Hypothalamic hormones, stored in median eminence, are secreted to primary plexus capillaries and via portal vein transported to secondary plexus capillaries, where cells of pars distal is are stimulated to synthesize and secrete their hormones into collecting vein.

Question 5

How are hormones in posterior pituitary cells released?

Answer 5

Oxytocin and ADH produced from supraoptic and paraventricular nuclei of hypothalamus are transported via hypothalamus-hypophyseal tract to para nervosa of neurophysis, where they are stored in axon terminals as neurosecretory granules (herring body).

Question 6

Describe hormones that are released from adrenal gland.

Answer 6

Cortex:Zona Glomerulosa: mineralocorticoid (aldosterone), stimulated by angiotensin and ACTH Zona Fasiculata: glucorticoid (cortisol) stimulated by ACTHZona Reticularis: weak androgen and cortisolMedulla: chromaffin cells receive direct sympathetic innervation and release epinephrine (less dense) and norepinephrine (dense body).