Take the example of the control of thyroid hormones from the thyroid gland in your neck. The hypothalamus produces a hormone called thyrotropin-releasing hormone (TRH). TRH travels to the pituitary gland and stimulates it to release thyroid-stimulating hormone (TSH). TSH travels to the thyroid gland and stimulates it to release thyroid hormones, T3 and T4. When levels of T3 and T4 get high enough, levels in the bloodstream are detected by the hypothalamus. The hypothalamus then knows to stop releasing more TRH. This last part of the loop is called negative feedback and prevents hormone levels from rising too high.
produces and releases hormones that affect growth, sexual development,
metabolism and the reproduction system, particularly the ovaries
and testes as well as the adrenal, kidneys, breasts, intestines,
bladder, uterus, stomach and spleen.
The posterior is composed of axons of hypothalamic neurons that extend downward as a large bundle behind the anterior. It also forms the pituitary stalk, which appears to suspend the anterior from the hypothalamous.
The above image on the is the frontal view of the pituitary gland and hypothalamus of a sheep. This image will hopefully give you some idea how the parts of this organ fit together.
Hormone secretion from the anterior pituitary is strictly controlled by hypothalamus hormones. The "hypothalamus" is a cluster of brain cells just above the pituitary gland, which transmits messages from the body to the brain.
For years, the pituitary gland was believed to be the master gland of the body, but now we know that the "hypothalamus" is the true "master gland" of the body. The hypothalamus is the link between the pituitary gland and the brain. It is akin to a way station between the body and the brain. It sorts out the messages to and from the body and responds accordingly through the pituitary gland.
The hypothalamus replies to the needs of the body by nerve impulses to the pituitary gland, which in turn produces the hormones the body's needs. These hormones are then circulated in the blood to the body's tissues, including other endocrines.
The anterior pituitary gland produces seven important hormones: human growth hormone (hGH), thyroid-stimulating hormone (TSH), follicle-stimulating hormone (FSH), luteinizing hormone (LH), prolactin (PRL), adrenocorticotropic hormone (ACTH), and melanocyte-stimulating hormone (MSH). Each of these hormones targets specific receptors in the body to stimulate specific glands and tissues in the body. The thyroid gland, ovaries, testes, mammary glands, and the cortex of the adrenal glands are all stimulated by the hormones of the anterior pituitary, resulting in the pituitary gland being known as the “master gland” for its control of the endocrine system. More modern studies now show that, while still important, the anterior pituitary is subservient to the control of the hormones of the hypothalamus. Releasing hormones from the hypothalamus, such as thyrotropin-releasing hormone (TRH) and gonadotropic-releasing hormone (GnRH), stimulate the anterior pituitary to release TSH, FSH, and LH. Inhibiting hormones, such as growth hormone-inhibiting hormone (GHIH), prevent the secretion of hormones hGH and TSH.