Rutgers Anatomy & Physiology II Practice Exam 2026 - Free Anatomy & Physiology Practice Questions and Study Guide

Erythrocytes, also known as red blood cells, are primarily responsible for the transport of oxygen in the bloodstream. They contain a protein called hemoglobin, which binds to oxygen molecules in the lungs and carries them to tissues and organs throughout the body. Each erythrocyte can carry about a billion molecules of oxygen, making them highly efficient in their primary role.

In addition to oxygen transport, erythrocytes also facilitate the transport of carbon dioxide, a waste product of metabolism, back to the lungs for exhalation. Their unique biconcave shape allows for a larger surface area, enhancing their ability to transport gases. The presence of hemoglobin is what gives red blood cells their characteristic color and also enables them to perform their critical function effectively. Understanding this role underscores why erythrocytes are central to respiratory physiology and overall metabolic processes within the body.