Which system includes ductless glands that regulate hormone production?

Which system includes ductless glands that regulate hormone production?

• A. Digestive
• B. Endocrine
• C. Reproductive
• D. Circulatory

Answer: (B)

Hormone regulation happens through ductless glands that release hormones directly into the bloodstream, which is the defining feature of the endocrine system. These glands—like the pituitary, thyroid, adrenals, pancreas, and reproductive glands—secrete chemical messengers that travel through the blood to target organs, controlling metabolism, growth, and reproductive processes. The other systems don’t describe this primary role: the digestive system focuses on breaking down food, the circulatory system transports substances (including hormones) but isn’t the source of them, and the reproductive system involves glands and hormones as part of its function but isn’t defined by ductless glands regulating hormone production.

Hormone regulation happens through ductless glands that release hormones directly into the bloodstream, which is the defining feature of the endocrine system. These glands—like the pituitary, thyroid, adrenals, pancreas, and reproductive glands—secrete chemical messengers that travel through the blood to target organs, controlling metabolism, growth, and reproductive processes. The other systems don’t describe this primary role: the digestive system focuses on breaking down food, the circulatory system transports substances (including hormones) but isn’t the source of them, and the reproductive system involves glands and hormones as part of its function but isn’t defined by ductless glands regulating hormone production.