How do hormones affect physiological functions?

Hormones function as chemical messengers that are secreted by glands in the endocrine system and circulate through the bloodstream to target organs or tissues. This allows them to regulate a wide array of physiological functions, including metabolism, growth and development, mood, immune function, and the body's response to stress. For example, insulin helps control blood sugar levels, while adrenaline prepares the body for 'fight or flight' responses.

This mechanism of action is integral to maintaining homeostasis within the body. The specificity of hormone functions is determined by the presence of receptors on target cells that can bind to these hormones, triggering a cascade of cellular responses and physiological changes. In this way, hormones play a crucial role in coordinating complex bodily processes efficiently and effectively.