Hormones have a wide range of effects on the body, acting as chemical messengers that regulate many different bodily functions. Step 1: Hormones are secreted by endocrine glands directly into the bloodstream. Step 2: The bloodstream carries the hormones to target cells or organs throughout the body. Step 3: Target cells have specific receptors on their surface or inside them that bind to particular hormones. Step 4: When a hormone binds to its receptor, it initiates a cellular response. These responses can include: Regulating metabolism* (e.g., insulin controlling blood sugar). Controlling growth and development* (e.g., growth hormone). Influencing mood and behavior* (e.g., adrenaline). Managing reproduction* (e.g., estrogen, testosterone). Maintaining homeostasis* (e.g., thyroid hormones regulating body temperature). Coordinating immune responses*.