Anatomy and Physiology II Practice Test

Red blood cells, also known as erythrocytes, primarily function to transport oxygen from the lungs to tissues throughout the body and carry carbon dioxide, a metabolic waste product, from the tissues back to the lungs for exhalation. This essential role is facilitated by a protein called hemoglobin, which binds oxygen in the lungs where it is abundant and releases it in tissues where it is needed. The ability to effectively transport these gases is crucial for maintaining cellular respiration and overall metabolic functions in the body.

The other functions mentioned in the options pertain to different components of blood. For instance, blood clotting is primarily the role of platelets and clotting factors, while antibodies are produced by B cells, a type of white blood cell, for immune responses. Regulation of body temperature is typically achieved through the activity of blood vessels and hormonal mechanisms rather than a direct function of red blood cells.