Growth hormone is also known as:
**Core Concept**
Growth hormone (GH) is a peptide hormone secreted by the anterior pituitary gland, playing a crucial role in regulating growth, metabolism, and body composition. It stimulates the production of insulin-like growth factor 1 (IGF-1), which mediates most of its effects on growth and development.
**Why the Correct Answer is Right**
Growth hormone exerts its effects through a complex mechanism involving the liver and other tissues. GH binds to its receptor on the surface of liver cells, activating a signaling cascade that ultimately leads to the production of IGF-1. IGF-1 then stimulates the proliferation and differentiation of cells, leading to growth and development.
**Why Each Wrong Option is Incorrect**
**Option A:** Prolactin is a hormone secreted by the anterior pituitary gland, but it is involved in lactation and reproduction, not growth.
**Option B:** Thyroid-stimulating hormone (TSH) regulates thyroid hormone production, which affects metabolism but is not directly related to growth hormone.
**Option C:** Adrenocorticotropic hormone (ACTH) stimulates the secretion of cortisol, a glucocorticoid involved in stress response and metabolism, but it is not growth hormone.
**Clinical Pearl / High-Yield Fact**
Growth hormone deficiency can result in short stature, delayed puberty, and increased risk of osteoporosis and cardiovascular disease.
**Correct Answer:** C. Somatotropin