Page 6 - Module 1-Anatomy and Physiology of Growth Hormone Function Final (Interactive)

Module 1: Anatomy and Physiology of Growth Hormone

The Hypothalamic-Pituitary-Somatropin

Axis

The Hypothalamic-Pituitary Somatropin axis (HPS axis), also known as the
hypothalamic-pituitary-growth axis , is a neuroendocrine unit that consists of the
hypothalamus, the pituitary gland, and also includes the secretion of growth hormone
(somatotropin). Insulin-like growth factor 1 (IGF-1) is subsequently released,
primarily by the liver, in response to GH stimulation. GH is secreted from the anterior
pituitary gland and is controlled by growth hormone releasing hormone (GHRH),
growth hormone-inhibiting hormone (GHIH), otherwise known as somatostatin, and
ghrelin. Once secreted, GH has important endocrine and paracrine functions.

Hypothalamus

The hypothalamus is located in the brain at the floor of the third ventricle within a
structure called the diencephalon, in front of and below the thalamus . The
hypothalamus produces and secretes several hormones and is structurally and
functionally linked to the pituitary gland.

Figure 2. Hypothalamus and pituitary gland

The anterior pituitary gland produces GH, also known as somatotropin, and is
located within the sella turcica, which is a cup-like bony structure in the skull.

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