What role do hormones play in the body?

Hormones play a crucial role in regulating physiological processes and maintaining homeostasis within the body. They are chemical messengers produced by endocrine glands that travel through the bloodstream to target organs or tissues, where they elicit specific responses. This regulation includes a broad range of functions, such as controlling metabolism, growth and development, immune function, mood, and reproductive processes.

For example, insulin, a hormone produced by the pancreas, helps regulate blood sugar levels by facilitating the uptake of glucose into cells. Similarly, thyroid hormones influence metabolic rate and energy levels, while cortisol helps the body respond to stress. By coordinating these various functions, hormones help the body adapt to changes, ensuring internal stability despite external fluctuations.

In contrast, the other options describe different biological functions that hormones do not perform. Storing nutrients for energy is primarily the role of fats and carbohydrates in the form of glycogen in the liver and muscles. Providing structural support to cells typically involves proteins, such as collagen. Finally, the transport of oxygen in the bloodstream is accomplished by hemoglobin, a protein found in red blood cells, rather than hormones. These distinctions affirm the unique and vital role that hormones play in maintaining overall health and balance in the body.