Anatomy Of Thyroid

Question 1

What type of C.T is thyroid capsule made of ?

Answer 1

Loose C.T

Question 2

Thyroid follicles

Answer 2

Spherical, follicular epithelium surrounding cavity with colloid thyroglobulin (acidophilic)

Question 3

Compare: Follicular & parafollicular (C) cells

Answer 3

Follicular: main cells lining the follicle, joined by apical junctional complex has microvilli, secrete T3 & T4, has cytoplasmic vesicles
C cells: called so cuz they’re lightly stained, membrane bound granules (Calcitonin & catecholamines), they secrete thyrocalcitonin (lowers calcium)

Question 4

Steps of thyroxin formation

Answer 4

1) protein part of TGN is formed in rER
2) galactose is added in the Golgi apparatus to form glycoprotein
3) It is secreted into the cavity then combines with iodine to form TGN
4) in need it enters again into follicular cells, gets converted to T3/T4 and enters blood