hypothalamus pituitary thyroid hormone

parathyroid anatomy axis body cells concept control design diagram education endocrine feedback function gland glycoprotein health hormone hormones human hypothalamus illustration infographic medical medicine metabolism negative neuroendocrine organ pituitary poster produce production releasing science secretion stimulating structure system thyroid thyrotrope thyrotropic thyrotropin thyroxine tissue trh triiodothyronine tsh vector