What is the primary function of erythrocytes in the human body?

Erythrocytes, also known as red blood cells, primarily function to transport oxygen from the lungs to the body's tissues and return carbon dioxide from the tissues back to the lungs. This is facilitated by the presence of hemoglobin, a protein within erythrocytes that binds oxygen as well as carbon dioxide, allowing for efficient gas exchange. Oxygen is essential for the metabolic processes of cells, providing the energy necessary for various bodily functions.

While erythrocytes are crucial for gas exchange, other functions like nutrient transport, temperature regulation, and fighting infections are carried out by different components of the circulatory and immune systems, such as plasma proteins, white blood cells, and other cell types. This specialization highlights the unique and vital role of erythrocytes in maintaining the body's oxygen supply and overall homeostasis.