pituitary gland      
noun [ C usually singular ]  anatomy specialized uk/pɪˈtʃuː.ɪ.tər.i ˌɡlænd/ us/pɪˈtuː.ə.ter.i ˌɡlænd/ (also pituitary)
 (脑下)垂体
a small organ at the base of the brain that controls the growth and activity of the body by producing hormones