Explanation
The Growth Hormone (GH), also known as somatotropin, is primarily secreted by the pituitary gland. Therefore, the correct answer is option D: Pituitary.
The pituitary gland is a small, pea-sized gland located at the base of the brain. It is often referred to as the "master gland" because it controls the functions of other hormone-secreting glands in the body. The pituitary gland produces and releases several hormones, including the Growth Hormone.
The secretion of Growth Hormone by the pituitary gland is regulated by the hypothalamus in the brain. The hypothalamus produces and releases Growth Hormone-Releasing Hormone (GHRH) and Growth Hormone-Inhibiting Hormone (GHIH), also known as somatostatin, which control the release of Growth Hormone by the pituitary gland.
In summary, the Growth Hormone is primarily secreted by the pituitary gland, and its secretion is regulated by the hypothalamus.
