Glands secrete hormones that regulate processes such as growth, reproduction, and nutrient use (metabolism) by body cells. Which system is described?

• A. Endocrine system
• B. Integumentary system
• C. Digestive system
• D. Cardiovascular system

Answer: (A)

Glands that secrete hormones to regulate growth, reproduction, and metabolism point to the endocrine system. Hormones are chemical messengers released into the bloodstream to reach distant target cells, where they control growth, development, and how efficiently body cells use nutrients. This system coordinates gradual, long‑lasting changes and works with the nervous system to manage bodily functions. Examples include growth hormone from the pituitary, metabolic regulation by thyroid hormone, insulin and glucagon from the pancreas, and sex hormones from the gonads. Other systems like the digestive, cardiovascular, or integumentary systems have different primary roles, though they can be influenced by hormonal signals.