Chapter 7. Metabolism
Hormonal Regulation of Metabolism
The Following chapter was obtained for free from OpenStax.[1].
Catabolic and anabolic hormones in the body help regulate metabolic processes. Catabolic hormones stimulate the breakdown of molecules and the production of energy. These include cortisol, glucagon, adrenaline/epinephrine, and cytokines. All of these hormones are mobilized at specific times to meet the body’s needs. Anabolic hormones are required to synthesize molecules and they include growth hormone, insulin-like growth factor, insulin, testosterone, and estrogen. Table 7.2 summarizes the functions of catabolic hormones and Table 7.3 summarizes the functions of the anabolic hormones.
| Hormone | Function |
|---|---|
| Cortisol | Released from the adrenal gland in response to stress; its main role is to increase blood glucose levels by gluconeogenesis (breaking down fats and proteins) |
| Glucagon | Released from alpha cells in the pancreas either when starving or when the body needs to generate additional energy; it stimulates the breakdown of glycogen in the liver to increase blood glucose levels; its effect is the opposite of insulin; glucagon and insulin are a part of a negative-feedback system that stabilizes blood glucose levels |
| Adrenaline/epinephrine | Released in response to the activation of the sympathetic nervous system; it increases heart rate and heart contractility, constricts blood vessels, is a bronchodilator that opens (dilates) the bronchi of the lungs to increase air volume in the lungs, and stimulates gluconeogenesis |
| Hormone | Function |
|---|---|
| Growth hormone (GH) | Synthesized and released from the pituitary gland; it stimulates the growth of cells, tissues, and bones |
| Insulin-like growth factor (IGF) | Stimulates the growth of muscle and bone while also inhibiting cell death (apoptosis) |
| Insulin | Produced by the beta cells of the pancreas; it plays an essential role in carbohydrate and fat metabolism, controls blood glucose levels, and promotes the uptake of glucose into body cells; it causes cells in muscle, adipose tissue, and liver to take up glucose from the blood and store it in the liver and muscle as glycogen; its effect is the opposite of glucagon; glucagon and insulin are a part of a negative-feedback system that stabilizes blood glucose levels |
| Testosterone | Produced by the testes in males and the ovaries in females; it stimulates an increase in muscle mass and strength as well as the growth and strengthening of bone |
| Estrogen | Produced primarily by the ovaries, but also by the liver and adrenal glands; its anabolic functions include increasing metabolism and fat deposition |
- Betts J. Gordon, Young KA, Wise JA, Johnson E, Poe B, Kruse BH, et al. Anatomy and Physiology 2e [Internet]. 2nd ed. Houston, Texas: Open Stax; 2022 [cited 2023 Mar 13]. Available from: https://openstax.org/books/anatomy-and-physiology-2e/pages/1-introduction ↵
