<unk> s (also called follicular<unk> s or principal<unk> s) are<unk> s 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<unk> s, below).
Thyroid epithelial cell
Chromaffin cell
Adipocyte
Parathyroid gland
Olfactory receptor neuron
Thyroid gland
Neuroepithelial cell
Beta cell