Page 7 - Module 1-Anatomy and Physiology of Growth Hormone Function Final (Interactive)

Module 1: Anatomy and Physiology of Growth Hormone

Some of the key functions of the hypothalamus include the following:

• Coordinates physiologic responses from several organs that independently and
collectively function to maintain homeostasis.

• Integrates signals from various internal and external sources and then elicits the
appropriate responses from the nervous and endocrine systems.

• Influences and regulates food intake, energy expenditure, body weight, fluid
intake and balance, blood pressure, thirst, body temperature, and the sleep cycle.

In addition, the hypothalamus maintains control through two primary mechanisms:
(1) release of neuropeptides, and (2) control of the anterior pituitary.

Release of neuropeptides - which are transported through the
hypothalamo-hypophyseal tract to the posterior pituitary.

Control of the anterior pituitary through the release of peptides that
mediate hormone release.

Because of the cooperation and interaction between the hypothalamus and the
pituitary, they are often considered as an integrated system rather than individual
anatomical components.

Gross anatomy
The median eminence is a structure within the hypothalamus that is important
because it is where hypothalamic neurons release neuropeptides that control the
function of the anterior lobe of the pituitary gland. The median eminence narrows to
form the posterior pituitary, which is actually an extension of the hypothalamus.
Communication with the pituitary gland

Hormones from the hypothalamus travel to the pituitary gland through a vascular
system called the hypothalamo-hypophyseal portal system which allows hormones
to diffuse through the wall and into the anterior lobe of the pituitary gland. The
connection between the hypothalamus and the posterior lobe of the gland forms a
stalk through which hormones synthesized in the hypothalamus are transported and
stored before release into the bloodstream.

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