Adrenal, thyroid, parathyroid

Question 1

Answer 1

Adrenal gland

cortex essential for life, not medula

Question 2

Answer 2

Adrenal gland

Green: zona glomerulosa

-10-15% of cortex, cells packed around capillaries, produce MCs - aldosterone

Navy: Zona fasciculata

• largest part of the cortex, cells appear washed out (high lipid content) - called spongiocytes
• produce steroid hormones e.g. cortisol

Aqua: zona reticularis

• darkly stained, small cells, ~10% of cortex
• synthesize mostly androgens

Medullary chromaffin cells on bottom - synthesize Epi and Norepi - innervated by paraganglionic fibers

Question 3

Answer 3

Adrenal gland

Oil Red O stains lipids red - cortex

medulla not stained

Question 4

Answer 4

Adrenal gland

Osmium stains lipids black

Zona fasciculata particularly stains dark - spongiocytes with high lipid content

Question 5

Answer 5

Thyroid gland

2 types of epithelium:

follicular (principal) epithelium and

parafollicular epithelium (C-cells)

Question 6

Answer 6

Thyroid follicle

Contains colloid - gel that contains precursor for thyroid hormones (thyroglobulin)

Surrounded by follicular/principal cells (blue arrows) - synthesize and secrete T3 and T4

Question 7

Answer 7

Thyroid follicles

White space between colloid and apical surface of follicular cells = cytoplasmic vesicles that are involved with endocytosis of colloid

Question 8

Answer 8

Parathyroid gland

Thin CT capsule

adipose tissue increases with age

Question 9

Answer 9

Parathyroid gland

Blue arrow: chief/principal cells - majority, secrete PTH

Blue circle: oxyphil cells - larger, distinctly eosinophilic, fxn unknown

Question 10

Answer 10

Parathyroid gland

Majority are PTH secreting principal/chief cells

fewer number of oxyphil cells