What is one of the primary functions of blood?

Blood performs several critical functions in the body, categorized as protection, transportation, and regulation.

In terms of transportation, blood is responsible for moving oxygen from the lungs to the cells throughout the body and carrying carbon dioxide from the cells back to the lungs. It also transports nutrients absorbed from the digestive tract to various tissues and organs, as well as hormones secreted by endocrine glands to their target tissues.

Regarding protection, blood contains components of the immune system, such as white blood cells and antibodies, which help defend against infections and disease. Additionally, it plays a vital role in hemostasis, preventing blood loss through the clotting process.

Regulation involves maintaining homeostasis by regulating body temperature, pH levels, and the osmotic balance of body fluids. Blood helps ensure that the internal environment remains stable despite external changes.

While options related to immunity, nutrient storage, and hormone production are important, they do not encompass the full range of primary functions of blood as effectively as the combination of protection, transportation, and regulation.