Which system regulates body processes through hormones?

• A. Nervous system
• B. Endocrine system
• C. Digestive system
• D. Circulatory system

Answer: (B)

Regulating body processes through hormones is the job of the endocrine system. Hormones are chemical messengers released by glands such as the pituitary, thyroid, adrenals, and pancreas. They travel through the bloodstream to target organs, coordinating growth, metabolism, energy use, and responses to stress and development. This signaling tends to produce slower, longer-lasting effects compared with the rapid responses of nerves. The nervous system handles quick actions via nerve impulses, not hormonal regulation. The digestive system uses hormones to help digestion, but its primary role isn’t regulating the body through hormonal signals. The circulatory system mainly transports blood (and the hormones it carries) but doesn’t itself regulate body processes through hormones; the regulation comes from the endocrine glands releasing those hormones.