Which system is primarily responsible for transporting nutrients, gases, and wastes?

Which system is primarily responsible for transporting nutrients, gases, and wastes?

• A. The circulatory (cardiovascular) system
• B. The endocrine system
• C. The nervous system
• D. The lymphatic system

Answer: (A)

Nutrients, gases, and wastes are moved around the body mainly by the circulatory system. The heart pumps blood through a network of vessels so oxygen and nutrients travel from the lungs and digestive system to every cell, and wastes like carbon dioxide are carried away to the lungs and kidneys for elimination. Blood is the transport medium: red blood cells carry oxygen, plasma carries dissolved nutrients and wastes, and the circulatory system integrates these tasks to keep cells fed and clean. Other systems aren’t built to serve as the primary transport network for all these substances. The endocrine system sends hormones through the blood to regulate processes, but its job isn’t bulk transport of nutrients and gases. The nervous system coordinates rapid control and communication, not the continuous distribution of nutrients and wastes. The lymphatic system helps manage fluid balance and immunity and moves certain fats, but it does not serve as the main route for delivering most nutrients or exchanging gases throughout the body.

Nutrients, gases, and wastes are moved around the body mainly by the circulatory system. The heart pumps blood through a network of vessels so oxygen and nutrients travel from the lungs and digestive system to every cell, and wastes like carbon dioxide are carried away to the lungs and kidneys for elimination. Blood is the transport medium: red blood cells carry oxygen, plasma carries dissolved nutrients and wastes, and the circulatory system integrates these tasks to keep cells fed and clean.

Other systems aren’t built to serve as the primary transport network for all these substances. The endocrine system sends hormones through the blood to regulate processes, but its job isn’t bulk transport of nutrients and gases. The nervous system coordinates rapid control and communication, not the continuous distribution of nutrients and wastes. The lymphatic system helps manage fluid balance and immunity and moves certain fats, but it does not serve as the main route for delivering most nutrients or exchanging gases throughout the body.