Follicles

Follicle = a small spherical group of cells containing a cavity

eg:

• Hair follicle at the root of hair aiding hair growth.
• Ovarian follicle = Basic units of ovary. Each ovarian follicle is made of one oocyte and its supporting cells.
• Thyroid follicle = Cuboidal cells surrounding fluid filled space called colloid. Has receptor for TSH
  • Para follicular cells are interspersed between Thyroid follicles. They produce calcitonin
• Lymph follicle = Lymph node