What is the main function of the endocrine system?

The main function of the endocrine system is to synthesize and secrete hormones. Hormones are chemical messengers that are produced by various glands in the body and released directly into the bloodstream. They play a crucial role in regulating numerous physiological processes, including metabolism, growth and development, tissue function, sexual function, reproduction, sleep, and mood.

This system coordinates and integrates body functions by signaling different cells and organs to respond to various stimuli, ensuring that physiological processes are maintained within a balanced state known as homeostasis. The precise action of hormones highlights the importance of the endocrine system in maintaining the health and functioning of the body across various stages of life.

The other options do not accurately represent the primary role of the endocrine system. Transporting oxygen in the blood is primarily a function of the circulatory system, regulating body temperature is chiefly handled by the hypothalamus in conjunction with the integumentary and muscular systems, and filtering toxins is a key function of the renal system, primarily performed by the kidneys.