And their receptors regulate the same variables in all species in which they are expressed. Always maintain a steady level of stimulation. Are the first forms of organified iodine appearing in evolution. Colloid droplets originate from the Golgi apparatus. Thyroglobulin is synthesized by the ribosomes of the ergastoplasm and processed through the Golgi.
Follicles are directly in contact with the blood.
The C cells originate from the ultimobronchial body. The volume of the colloid lumen depends on the relative rates of thyroglobulin synthesis and endocytosis. With iodide exerts the main control on thyroid. Activates only the cyclic AMP cascade in human thyroid. Desensitizes only slightly its receptor.