Hypothalmus and Pitutary Gland

The hypothalamus is a region of the brain that controls an immense number of bodily functions. It is located in the middle of the base of the brain, and encapsulates the ventral portion of the third ventricle.

The pituitary gland, also known as the hypophysis, is a roundish organ that lies immediately beneath the hypothalamus, resting in a depression of the base of the skull called the sella turcica ("Turkish saddle") Careful examination of the pituitary gland reveals that it composed of two distinctive parts: The anterior pituitary or adenohypophysis is a classical gland composed predominantly of cells that secrete protein hormones. The posterior pituitary or neurohypophysis is not a separate organ, but an extension of the hypothalamus. It is composed largely of the axons of hypothalamic neurons which extend downward as a large bundle behind the anterior pituitary. It also forms the so-called pituitary stalk, which appears to suspend the anterior gland from the hypothalamus.

 Secretion of hormones from the anterior pituitary is under strict control by hypothalamic hormones.A key to understanding the endocrine relationship between hypothalamus and anterior pituitary is to appreciate the vascular connections between these organs.