Growth hormone

Definition

Growth hormone (GH), also known as somatotropin, is a peptide hormone produced by the anterior pituitary gland that plays a crucial role in growth, metabolism, and body composition. It stimulates growth in tissues and bones, and influences various metabolic processes, connecting it to the broader spectrum of hormones and their functions within the endocrine system.

5 Must Know Facts For Your Next Test

1. Growth hormone is secreted in pulses, with levels peaking during sleep and physical exercise, and decreasing with age.
2. It promotes protein synthesis, increases muscle mass, and aids in fat metabolism, making it essential for overall physical development.
3. Excessive production of growth hormone can lead to acromegaly in adults, a condition characterized by abnormal growth of bones and tissues.
4. Deficiency in growth hormone during childhood can result in stunted growth and developmental delays, known as growth hormone deficiency syndrome.
5. Growth hormone also plays a role in regulating body composition by increasing lipolysis, which helps to reduce fat mass while preserving lean muscle.

Review Questions

• How does growth hormone influence both physical growth and metabolism in the body?
  • Growth hormone influences physical growth by stimulating the liver to produce insulin-like growth factor 1 (IGF-1), which promotes growth in bones and tissues. It also enhances protein synthesis, leading to increased muscle mass. In terms of metabolism, GH stimulates lipolysis, which breaks down fats for energy, thus affecting body composition by reducing fat mass while preserving lean tissue.
• Discuss the role of the hypothalamus in regulating the secretion of growth hormone from the pituitary gland.
  • The hypothalamus plays a critical role in regulating growth hormone secretion by producing specific hormones that signal the pituitary gland. It releases growth hormone-releasing hormone (GHRH), which stimulates the release of GH, and somatostatin, which inhibits its release. This intricate feedback system ensures that GH levels are appropriately adjusted according to the body’s needs for growth and metabolism.
• Evaluate the implications of both excess and deficiency of growth hormone on human health throughout different life stages.
  • Excessive production of growth hormone can lead to acromegaly in adults, causing abnormal enlargement of bones and tissues, resulting in serious health complications such as cardiovascular disease. On the other hand, deficiency during childhood can lead to significant stunted growth and delayed developmental milestones. Understanding these conditions highlights the importance of balanced GH levels for healthy development and maintenance across various life stages.

Related terms

Pituitary Gland: A small gland located at the base of the brain that produces hormones regulating various bodily functions, including growth hormone.

Insulin-like Growth Factor 1 (IGF-1): A hormone that is primarily produced in the liver as a response to growth hormone stimulation, promoting growth and development of tissues.

Hypothalamus: A region of the brain that controls the pituitary gland and regulates the release of growth hormone through the secretion of growth hormone-releasing hormone (GHRH) and somatostatin.