In addition to oxygen and carbon dioxide transport, what is another function of blood?

Blood serves multiple essential functions in the body beyond just the transport of oxygen and carbon dioxide. One key function is its role in the immune response. Blood contains various components such as white blood cells, antibodies, and various proteins that are crucial for defending the body against pathogens and foreign invaders. These components work together to identify, target, and destroy harmful substances, enhancing the body's ability to fight infections and disease.

The immune system relies on the circulation of blood to ensure that immune cells can efficiently reach contaminated areas and carry out their protective functions throughout the body. This is fundamental for maintaining health and responding to infections, emphasizing the importance of blood in the immune response.

Other options, while related to bodily functions, do not encapsulate the primary roles blood plays outside of transport. For instance, heat exchange involves the distribution of heat but is typically regulated by other mechanisms beyond blood. Fluid absorption mainly occurs in the digestive system and is not a direct function of blood. Nutrient breakdown happens at the cellular level and is separate from blood's role in delivering nutrients. Thus, blood's critical function in immune response is a significant aspect of its overall role in the human body.