Adrenal histology

Question 1

Which species have zona glomerulosa?

Answer 1

Primates and ruminants

Question 2

Which species have a zone arcuate (instead of a glomerulosa)?

Answer 2

Cat, dog, horse, pig

Arcuata = arched stacks

Question 3

Describe the zone fasciculate.

Answer 3

Vacuolated (lipid-rich) parenchymal cells
Arranged in rows/columns
Capillaries b/t columns

Question 4

Describe zona reticulares

Answer 4

• Small, eosinophilic cells
• Less vacuolated than zona fasciliaris
• Anastomosing networks

Question 5

EM: Steroid-secreting v Protein-secreting cells

Answer 5

Steroid-secreting:

• Extensive smooth ER
• ROUND mitochondria (where cholesterol becomes pregnenolone)
• Lipid droplets (store cholesterol); as large as mitochondria
• Coated pits (where LDL enters)

Peptide-secreting:

• Rough ER
• Skinny mitochondria
• Secretory granules (smaller than lipid droplets)

Question 6

Describe chromaffin cells

Answer 6

Round to columnar
Clusterd
Slightly granular

May be near sympathetic ganglion cells (bulls-eye)