Thyroid epithelial cell

Overview
Thyroid epithelial cells (also called follicular cells or principal cells) are cells in the thyroid gland which produce and secrete thyroxine (T4) and triiodothyronine (T3).

They are simple cuboidal epithelium and are arranged in spherical follicles surrounding colloid.

They have thyrotropin receptors on their surface, which respond to thyroid-stimulating hormone.

Embryologic origin is from endoderm (in contrast to parafollicular cells, below).

Relationship to other cell types
Calcitonin-producing parafollicular cells (C cells) can be found scattered along the basement membrane of the thyroid epithelium. Embryologic origin is from neural crest cells.