HISTOLOGY OF THYROID AND PARATHYROID GLAND Connective tissue component Parenchym atous component Parenchyma is made up of Thyroid follicles Parafollicular cells or C cells INACTIVE THYROID GLAND The follicles are lined by epithelial cell responsible for the synthesis of the glycoprotein component of thyroglobulin Conversion of iodide to iodine Thyroid epithelial cells are simple flat or cuboidal cells ACTIVE THYROID GLAND Active glands have more follicles and their epithelium is tall and columnar PARAFOLLICULAR OR C, CELL Parafollicular cells, derived from neural crest cells larger than follicular cells and Singly or in groups. Cells are polyhedral with oval eccentric nucleus

1. HISTOLOGY OF THYROID
AND PARATHYROID
GLAND

3. 1)Connective
tissue
component
2)Parenchym
atous
component

4. Parenchymais
made up of
1) Thyroid
follicles
2)Parafollicular
cells or Ccells

7. The follicles are lined by epithelial cell responsible for
the synthesis of the glycoprotein component of
thyroglobulin
Conversion of iodide to iodine
Thyroid epithelial cells are simple flat or cuboidal cells
INACTIVE THYROID GLAND

8. Active glands have more follicles and their epithelium is tall and columnar
ACTIVE THYROID GLAND

9. Storage & Release of Thyroid Hormone

11. Parafollicular cells, derived from neural crest cells
larger than follicular cells and
Singly or in groups.
Cells are polyhedral with oval eccentric nucleus
PARAFOLLICULAR OR C, CELL

12. They have a smaller amount of rough ER, large Golgi complexes, and granules
These cells synthesize and secrete calcitonin,
Decrease calcium level
Suppress bone resorption by osteoclasts.
PARAFOLLICULAR OR C, CELL

14. The parathyroid glands are four small oval. They are located on the back of the thyroid gland,
one at each end of the upper and lower poles, usually embedded in the larger gland's
capsule
PARATHYROID GLANDS

15. Two types of cells are present in parathyroid glands: chief (or principal) cells and oxyphil
cells
STRUCTURE OF PARATHYROID GLAND

16. Small polygonal cells with round
nuclei and pale-staining, cytoplasm.
Ultrastructurally the cytoplasm filled
with irregularly shaped granules
(containing (PTH),
CHIEF CELLS

17. These are much larger than the principal cells
and are characterized by acidophili cytoplasm
filled with abnormally shaped mitochondria.
suggesting these cells are transitional
derivatives from chief cells.
oxyphil cells