What is the primary function of the endocrine system?

The primary function of the endocrine system is to regulate bodily functions through hormone secretion. The endocrine system is a network of glands that produce and release hormones into the bloodstream. These hormones act as chemical messengers, influencing a variety of physiological processes such as metabolism, growth, reproduction, and mood regulation. By releasing hormones in response to various stimuli, the endocrine system helps maintain homeostasis and ensures that the body's systems work together harmoniously.

In contrast, the other options relate to different systems and functions of the body. For example, transporting oxygen in the blood is primarily the role of the cardiovascular system, particularly through red blood cells containing hemoglobin. Providing structural support to the body is the function of the skeletal system, which includes bones and connective tissues. Lastly, facilitating movement through muscle contractions is the job of the muscular system. Thus, the role of the endocrine system is specifically focused on hormonal regulation.