Endocrine Histology

Question 1

High power vs low power

Answer 1

HIGH POWER
- nuclei more pronounced

LOW POWER
- larger structures

Question 2

THYROID GLAND

Answer 2

• large follicles w/ pink colloid substance - stains pink!
• lined by secretory epithelial cells: release hormones
• simple cuboidal epithelium
• parafollicular cells found in clumps more pink outside the follicles = CALCITONIN
• empty space = capillary vessels, lined by simple epithelium

Question 3

PARATHYROID GLAND

Answer 3

x4 posterior , not much organisation, go by colour

CHIEF CELLS (purple pink)
secrete hormone (PTH) = calcium bone resorption = increase plasma levels 

OXYPHIL CELLS (stain lighter pink); exist in clumps

• DUCTS
  +adipocytes (visible in low mag) dehydrated upon fixing tissue

Question 4

Significance of mucus producing cells and fat cells under histology

Answer 4

MUCUS PRODUCING CELLS do not take up stains very well so will be pale/lack colour but still have visible nucleus

ADIPOCYTES are often dehydrated and therefore empty

Question 5

PITUITARY GLAND VASCULATURE & GENERAL SECRETIONS ETC.

Answer 5

ant. pit + pit stalk =
- formed separately from posterior pit.
- arises from branchial arches embryologically

• superior hypophyseal artery > capillaries carry releasing hormone > veins to anterior pit.
• hypophyseal portal veins (portal veins collect blood from x and distribute to y via capillaries)

• inferior hypophyseal artery

Question 6

HISTOLOGY OF THE ANT PIT.

Answer 6

(high power) = not much organisation
ACIDOPHIL CELLS = DARKER PINK
* secrete somatotrophic hormones inducing direct action
= GH, PROLACTIN
BASOPHIL CELLS = PURPLE
* secrete tropic hormones
= TSH, LH, FSH, ACTH

CHROMOPHOBE CELLS = Pale cell (resting cell non-secretory)

+ CAPILLARIES lined by SIMPLE SQUAMOUS EPITHELIUM

Question 7

POSTERIOR PIT. HISTOLOGY

Answer 7

neural tissue arrangement =

axons (myelin) = stain pale; foamy
herring bodies = collection of secretory granules
capillaries

Question 8

SUPRARENAL GLANDS

Answer 8

yellow cortical structure (cholesterol)
red medullary structure (vascular)

CAPSULE then GFR

Z. GLOMERULOSA (cortex) = SALT (mineralcorticoids)
ring-like cup structures
• aldosterone

ZONA FASCICULATA (cortex) = SUGAR (corticosteroids)
long rows of cells
• cortisol

ZONA RETICULARIS (cortex) = SEX (androgens)
network arrangement

• DHEA
ADRENAL MEDULLA = Adrenaline & NA (SYMPATHETIC)
* act similarly to sympathetic ganglia
* highly vascular - veins

Question 9

ORIGIN OF THE SUPRARENAL GLANDS

Answer 9

CORTICAL STRUCTURES ARE OF MESODERM ORIGIN

MEDULLARY STRUCTURES ARE OF NEURAL CREST ORIGIN

Question 10

WHAT TYPE OF SECRETIONS DO PANCREAS MAKE

Answer 10

Serous enzymatic secretions; will stain unlike mucus secretions