Hypothalamic–pituitary–gonadal axis
（重定向自HPGA）
The hypothalamic–pituitary–gonadal axis (HPG axis) refers to the effects of hypothalamus, pituitary gland, and gonadal glands as if those individual endocrine glands were a single entity as a whole. Because these glands often behave in cooperation, physiologists and endocrinologists find it convenient and descriptive to speak of them as a single system.