BIOL-2230 Lecture Notes - Lecture 2: Thyroid, Thyroglobulin, Follicular Cell
Document Summary
Largest gland and it only has endocrine functions. It has 2 lobes that are connected on the front by the isthmus. It has cuboidal epithelial cells called follicular cells and then parafollicular cells: follicular cells: Excretes thyroglobulin which is not a hormone, but a protein. This protein is a precursor for hormones: to develop thyroid hormone, thyroglobulin combines with iodine, the thyroglobulin and hormones are stored in a structure called a colloid, parafollicular cells: Produce the hormone, calcitonin: it cannot be stored, only secreted. There are 2 types of thyroxin: t3 and t4: t3 : tells us how well cells are absorbing thyroxin. Almost all cells have receptors: brain, testes, spleen, uterus, and thyroid gland are the only structures/cells without receptors for it. Tuesday, january 23, 2018: t4 : tells us how active the thyroid is. Regulates the metabolic rate and heat production: most important activity is oxidation of glucose (atp production)
