Which system transports nutrients and oxygen?

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

Answer: (B)

The circulatory system is responsible for transporting nutrients and oxygen to cells throughout the body. Blood, pumped by the heart through arteries, carries nutrients absorbed from the digestive system to tissues everywhere. It also delivers oxygen, carried by red blood cells bound to hemoglobin, from the lungs to cells that use it for energy.

The other systems don’t primarily move these substances around the body. The nervous system mainly transmits impulses and coordinates responses. The digestive system processes and absorbs nutrients but doesn’t distribute them to every part of the body. The respiratory system handles gas exchange, bringing oxygen into the blood and removing carbon dioxide, but it’s the circulatory system that distributes both oxygen and nutrients to tissues.