What are hormones primarily responsible for?

Hormones are primarily responsible for acting as chemical messengers in the body. They are produced by glands in the endocrine system and are released into the bloodstream, where they travel to various organs and tissues to regulate a wide range of physiological processes. Hormones influence growth and development, metabolism, immune function, emotion, and mood, among other vital functions. Their role as chemical messengers allows for communication between different parts of the body, enabling the synchronization of bodily functions in response to internal and external changes. This regulatory capacity is essential for maintaining homeostasis, the body's stable internal environment.

The other options describe functions that are more specific to different systems or processes in the body. For example, while regulating neural impulses refers to the nervous system's function, it is not the primary role of hormones. Managing muscle movements is primarily governed by motor neurons rather than hormones. Facilitating digestive processes involves various enzymes and substances, with hormones like gastrin playing a specific supporting role, but they are not the primary agents in digestion as a whole. Therefore, the correct answer highlights the essential and overarching function of hormones in bodily communication and regulation.