Answers

Pituitary Gland

#74 Pituitary, Human. H & E

What kinds of cells are in the neurohypophysis?
Pituicytes (glia), endothelial cells.

#75 Pituitary, Human (Chrome-hematoxylin and Phloxin)

• What do Herring bodies represent?
  Sites for storage or degradation of neurotransmitters.

• What hormones might you expect to find in these structures?
  Vasopressin (antidiuretic hormone) and oxytocin.

• Where are the hormones of the neurohypophysis synthesized?
  Hypothalamus.

Adrenal Gland

#71 Adrenal, Human, dichromate fixation

• What hormone is produced by the zona glomerulosa?
  Mineralocorticoids.

• By the zona fasciculata?
  Glucocorticoids (cortisol in humans).

• By the zona reticularis?
  Weak androgens.

• By the medulla?
  Epinephrine (adrenaline) and norepinephrine (noradrenalin).

• What hormones regulate the function of the cortex?
  ACTH, angiotensin II, epinephrine, norepinephrine.

• How is medullary function regulated?
  Presynaptic nerves and glucocorticoids.

QUESTIONS

1. What is the functional significance of the hypothalamo-hypophyseal system? It allows for rapid and direct delivery of hypothalamic products with releasing and inhibiting effects on anterior pituitary cells
2. What factors control the secretion of parathyroid hormone? Serum calcium levels
3. What is the consequence of parathyroid hypofunction? Lowered blood calcium level can be life threatening.
4. How does parathyroid hormone act? Raises serum calcium levels by acting on osteoblasts that in turn activate osteoclasts (release calcium from bone).