The endocrine glands are organs that synthesize and secrete biologically active substances called hormones, releasing them directly into the circulating blood.
The central endocrine glands are located in the brain and regulate the functions of many of the peripheral endocrine glands. The central endocrine glands include the following:
The peripheral endocrine organs can be divided into two groups. The first are the endocrine organs that are subordinated to the hypothalamic-pituitary system, and they include:
The second group includes the endocrine glands that are not directly controlled by the hypothalamic-pituitary system, such as: