What is the primary function of veins?

What is the primary function of veins?

• A. Transport blood away from the heart to the tissues
• B. Transport blood to the heart from the capillaries
• C. Exchange substances with tissues
• D. Return lymph to the circulatory system

Answer: (B)

Veins return blood to the heart after it has passed through the capillary beds in tissues. They operate at lower pressure than arteries and often have valves to prevent backflow, guiding blood back toward the heart from the body's tissues. This return function is why transporting blood to the heart from the capillaries is the best description of what veins do. Arteries move blood away from the heart, capillaries are the sites of substance exchange with tissues, and lymph moves through the lymphatic system rather than the blood venous system.

Veins return blood to the heart after it has passed through the capillary beds in tissues. They operate at lower pressure than arteries and often have valves to prevent backflow, guiding blood back toward the heart from the body's tissues. This return function is why transporting blood to the heart from the capillaries is the best description of what veins do. Arteries move blood away from the heart, capillaries are the sites of substance exchange with tissues, and lymph moves through the lymphatic system rather than the blood venous system.