What is the primary function of the endocrine system?

The primary function of the endocrine system is to secrete hormones that regulate various physiological processes, including growth and development. Hormones are chemical messengers produced by endocrine glands that circulate in the bloodstream and affect target organs and tissues. For instance, hormones such as growth hormone influence growth patterns, while thyroid hormones regulate metabolism. This system plays a crucial role in several other vital processes throughout the animal's life cycle, helping maintain homeostasis and responding to environmental changes.

In contrast, regulating body temperature involves mechanisms primarily governed by the nervous system and thermoregulatory responses rather than hormone secretion. While the endocrine system can influence behavior indirectly through hormonal effects, it does not control behavior directly. Similarly, while hormones may have some role in facilitating digestion through regulation of digestive processes, the primary responsibility for those functions lies with the digestive system itself. Thus, the key focus of the endocrine system is its role in hormone secretion and the regulation of growth and development.