Which system is primarily responsible for circulating blood to transport substances around the body?

Which system is primarily responsible for circulating blood to transport substances around the body?

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

Answer: (C)

The circulatory system is the one that moves blood through the body, acting as the transport network for carrying substances to and from tissues. It includes the heart that pumps, and the blood vessels that carry blood everywhere. Through this system, oxygen and nutrients are delivered to cells, carbon dioxide and wastes are carried away, hormones travel to their targets, immune cells patrol the body, and body temperature and pH are helped to stay balanced. The digestive system handles breaking down food and absorbing nutrients, but it doesn’t move blood around. The nervous system coordinates actions and responses, not circulation. The endocrine system releases hormones into the blood, but its primary role is signaling and regulation rather than circulating blood itself. That central function of circulating blood throughout the body to transport various substances is what the circulatory system does best.

The circulatory system is the one that moves blood through the body, acting as the transport network for carrying substances to and from tissues. It includes the heart that pumps, and the blood vessels that carry blood everywhere. Through this system, oxygen and nutrients are delivered to cells, carbon dioxide and wastes are carried away, hormones travel to their targets, immune cells patrol the body, and body temperature and pH are helped to stay balanced.

The digestive system handles breaking down food and absorbing nutrients, but it doesn’t move blood around. The nervous system coordinates actions and responses, not circulation. The endocrine system releases hormones into the blood, but its primary role is signaling and regulation rather than circulating blood itself. That central function of circulating blood throughout the body to transport various substances is what the circulatory system does best.