Which system secretes hormones that regulate growth, reproduction, and metabolism?

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

Answer: (A)

Hormones act as chemical messengers that travel through the bloodstream to regulate growth, reproduction, and metabolism. The endocrine system is made up of glands that secrete these hormones, coordinating long-term processes across the body. Because it specializes in producing and releasing signals that influence development, energy use, and reproductive cycles, it best fits the description. The nervous system governs rapid, moment-to-moment changes with electrical signaling, while the digestive and circulatory systems don’t primarily regulate growth and metabolism through hormone secretion.