What is the Origin of Term 18?

This term is a central element of endocrinology, with the discovery of GH dating back to the early 20th century, followed by the identification of its hypothalamic and pituitary control mechanisms. The recognition that GH's anabolic effects are primarily mediated by IGF-1 solidified the understanding of this entire signaling cascade as a cohesive axis. Its clinical significance spans from pediatric growth disorders to adult deficiency syndromes.

What is the Mechanism of Term 18?

The hypothalamus releases GHRH to stimulate and somatostatin to inhibit the release of GH from the anterior pituitary in a distinct pulsatile pattern, particularly during deep sleep. Once released, GH travels to the liver, where it stimulates the production and release of IGF-1, which is the primary effector molecule for promoting cellular proliferation, protein synthesis, and bone growth. GH also exerts direct metabolic effects, such as increasing lipolysis and antagonizing insulin action, illustrating its dual role in growth and energy regulation.

Term 18 ∞ Area

Term 18

Meaning

The Growth Hormone (GH) Axis, formally known as the Hypothalamic-Pituitary-Somatotropic axis, is the neuroendocrine system responsible for regulating growth, cellular repair, body composition, and metabolism throughout the lifespan. It is governed by the hypothalamus releasing Growth Hormone-Releasing Hormone (GHRH) and somatostatin, which together control the pulsatile secretion of Growth Hormone from the pituitary gland. GH then mediates its effects largely indirectly through the production of Insulin-like Growth Factor 1 (IGF-1) in the liver. Clinical assessment is important for evaluating vitality, lean mass maintenance, and tissue regeneration.