Adrenals

Question 1

Zona glomerulosa is….% of cortex, fasciculata is…..%, reticularis is ……%

Answer 1

10-15
65-80
10

Question 2

Describe LM appearnace of zona glomerulosa

Answer 2

It consists of closely packed arched or rounded cords of columnar or pyramidal cells with fenestrates b.c. (between goleruli & arcades)
The cells have acidophilic cytoplasm with lipid droplet appear as vacuoles in H&E.
Nucleus is deeply stained with one or two nucleoli

Question 3

Describe EM appearnace of zona glomerulosa

Answer 3

Abundant sER with branching & anastomosing tubules & nearby lipid droplets
Numerous mitochondria with tubular cristae
Golgi complex, few rER & ribosomes

Question 4

Zona glomerulosa secretes……

Answer 4

Mineralocorticoids mainly aldosterone

Question 5

Describe LM appearnace of zona fasciculata

Answer 5

Polygonal cells arranged in longitudinal cords or columns (one cell thick) that are cont with cells of z.g. separated by FBC
Cells have central rounded vesicular nuclei some are binucleated, cytopalsm is acidophilic vacuolated thus called spongioblasts. Lipid droplets contain ChEs which are orecusors of steroid hormones, also rich in vit C.

Question 6

Describe EM appearnace of zona fasciculata

Answer 6

Spongioblasts have extensive sER tubule network, lipofuscin granules, rest of features like glomerulosa

Question 7

Spongiocytes secrete……

Answer 7

Glucocorticoids

Question 8

Describe LM appearnace of zona reticularis

Answer 8

Cells are usually more darkly stained than other zones, bec they contain fewer lipid droplets
Polygonal cells arranged in branching & anastomosing cords forming a reticulum with FBC
2 types of cells: light cells (lightly stained with pale nuclei & abundant sER), dark cells Near medulla with pyknotuc nuclei & lipofuscin granules, may be degenerated cells.

Question 9

Zona reticularis secretes…….

Answer 9

Sex hormones mainly androgens as DHEA converted to testosterone
Few glucocorticoids

Question 10

Describe LM appearnace of medulla

Answer 10

Contain 2 cells:
1. Chromaffin cells: large polyhedral cells arranged in branching & anastomosing cords around FBC, finely granular basophillic cytoplasm, large vesicular & eccentric nuclei.
2. Ganglion cells: scattered or grouped sympathetic ganglion cells in medulla of adrenals.

Question 11

List & explain staining methods of chromaffin cells

Answer 11

1. Chromaffin reaction: treatment of fresh tissue of adrenal medulla by oxidizing agent (K dichromate), granules are stained brown (contain CAs)
2. Stained red with iodine

Question 12

Describe EM appearnace of medulla

Answer 12

Well-developed golgi, mitochondria, rER & secretory granules, 2 types of cells:
A. NA-secreting cells: contain granules (200-300 nm) with electron dense core surrounded by pale halo.
B. A-secreting cells: contain homogenous & less electron dense granules.

Question 13

What is the importance of adrenal cortex having no venous drainage?

Answer 13

Venous blood is collected at corticomedullary junction that drain in large central vein of medulla to IVC.
Blood arriving to medulla throigh cortex has high conc of glucocorticoids which may be required for the induction of the enzyme that catalyzes methylation of NE to E