Anatomy books

Tuesday, June 5, 2018

Histology of thyroid gland with brief description of Thyroid follicle


Thyroid follicle
It is the structural unit of thyroid gland
Difference between follicular cells and para-follicular cells
Histologically Thyroid gland has following parts
1.      Capsule
2.      Parenchyma (glandular portion )
3.      Stroma  (supporting structure : connective tissue )
Parenchyma (glandular portion )
Glandular portion is formed by two types of cells
1.      Follicular cells
2.      Parafollicular cells
These two types of cells formed a definite structure known as thyroid follicle
Parts of thyroid follicle
It is a round structure contain a lumen and wall of thyroid follicle is lined by follicular cells and its basement membrane, so follicular cells are facing toward the follicular lumen.
Some whitish or pale colour bubbles are observed near the apical region of follicular cells , what is this ?
They are secretory vesicle which contain secretion of follicular cells and come out from the follicular cell into colloid by the process of exocytosis
        Again secretion of the colloid enter into the follicular cell by the process of endocytosis.   
Parafollicular cells are present peripheral part of follicular wall but within the basement membrane and it never exposed to lumen of thyroid follicle

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