What are the primary functions of blood?

What are the primary functions of blood?

• A. Transport, protect, and regulate
• B. Oxygen transport only
• C. Immunity only
• D. Hormone production

Answer: (A)

Blood serves three broad roles: it transports substances through the body, protects via immune defenses and clotting, and helps regulate ongoing conditions like temperature and pH. Red blood cells carry oxygen to tissues and help remove carbon dioxide; white blood cells and antibodies defend against pathogens; platelets and clotting factors prevent excessive bleeding. This combination of moving gases, nutrients, and wastes; defending against disease and injury; and helping maintain stable conditions makes “transport, protect, and regulate” the best description of blood’s primary functions. Focusing only on oxygen transport misses other crucial duties like removing CO2, distributing nutrients and hormones, and maintaining temperature and pH. Saying immunity is the sole job ignores the transport and regulatory roles, and claiming hormones are produced by blood is incorrect—the glands produce hormones; blood mainly serves as the highway that carries them to target tissues.

Blood serves three broad roles: it transports substances through the body, protects via immune defenses and clotting, and helps regulate ongoing conditions like temperature and pH. Red blood cells carry oxygen to tissues and help remove carbon dioxide; white blood cells and antibodies defend against pathogens; platelets and clotting factors prevent excessive bleeding. This combination of moving gases, nutrients, and wastes; defending against disease and injury; and helping maintain stable conditions makes “transport, protect, and regulate” the best description of blood’s primary functions.

Focusing only on oxygen transport misses other crucial duties like removing CO2, distributing nutrients and hormones, and maintaining temperature and pH. Saying immunity is the sole job ignores the transport and regulatory roles, and claiming hormones are produced by blood is incorrect—the glands produce hormones; blood mainly serves as the highway that carries them to target tissues.