Thyroid/Pancreatic Histology

Question 1

The colloid of a thyroid follicle contains

Answer 1

Thyroglobulin

Question 2

Describe thyroid follicle cells

Answer 2

• Simple cuboidal
• Apical side (w/microvilli) faces colloid [contain peroxidase)
• Basolateral side sits near fenestrated capillaries
• rER

Question 3

The apical side of a parafollicular cell faces

Answer 3

Capillaries (opposite of follicular cells)

Question 4

Describe parafollicular cells

Answer 4

Ample secretory granules containing calcitonin

Question 5

Describe parathyroid glands

Answer 5

• Small round cells arranged in cords
• Chief cells secrete PTH
• Oxyphil cells = lighter, hi mitochondrial content

Question 6

Oxyphil cells are present in the parathyroid of which species?

Answer 6

Ruminants, horse, and human

Question 7

Which 3 cell types make up the islet of langerhan, where are they located, and what do they secrete?

Answer 7

B-cells - center - insulin
A-cells - glucagon - rim
D-cells - somatostatin - rim
(placement varies)

Question 8

What is a feature unique to pancreatic A and B cells?

Answer 8

MEMBRANE-BOUND secretory vesicles

Question 9

Islet of Langerhans is surrounded by

Answer 9

CT fibrils

Question 10

Thyroid peroxidase (in the microvilli of follicular cells) catalyzes which reaction?

Answer 10

IodiDe (from capillaries) to IodiNe (added to thyroglobulin in colloid before product is taken back in by follicular cells)

Question 11

How does thyroid histology change with age?

Answer 11

1. Unused colloid increases

2. Follicular cells transition from simple cuboidal to squamous