How do hormones primarily affect the body?

Hormones primarily affect the body by regulating bodily functions. They serve as chemical messengers produced by glands in the endocrine system and travel through the bloodstream to target organs and tissues. These hormones play a critical role in a wide range of physiological processes, including metabolism, growth and development, tissue function, reproductive processes, and mood regulation.

For example, insulin, which is secreted by the pancreas, helps to regulate blood glucose levels, while thyroid hormones influence the metabolic rate of cells throughout the body. This regulatory action ensures that various bodily functions operate in harmony, maintaining homeostasis and responding appropriately to internal and external stimuli.

Other answers do touch on aspects of bodily functions but do not encompass the full scope of hormonal influence. Generating heat is more specific to thermoregulation and metabolism rather than a function that defines hormonal action. Promoting muscular contraction is a function regulated by hormones like adrenaline and testosterone, but this is only a subset of broader regulatory roles that hormones perform. Storing energy is an outcome of metabolic processes influenced by hormones like insulin and glucagon but does not capture the comprehensive regulatory nature of hormones. Thus, the function of hormones is fundamentally centered on their regulatory capabilities across various bodily systems.