Thyroid Gland

Thyroid Gland

1. Parathyroid glands

   • 4-8 small endocrine glands
   • involved in disease process

2. covered by connective tissue capsule and its ductless

3. each lobule is composed of follicles- irregular shaped masses imbedded in mesh work of reticular fibers

   • each follicle has cuboidal epithelium enclosing a cavity filled by colloid (stiff material)-- producing thyroxine

4. produces thyroxine & other hormones into blood

5. first endocrine gland to develop (24th day) from endoderm invaded by mesenchyme

6. forms from median downgrowth connected by throglossal duct

   • foramen secum- opening of the thyroglossal duct where sulcus terminalis point backward- origin of the thyroid and migration pathway