The first main function is to absorb erythrocytes oxygen in the lungs and transfer it into the tissue and capillaries in the absorption of carbon dioxide in the capillaries of tissues and sending it to the lungs. This function is performed by hemoglobin.
The implementation of this function is crucial erythrocyte surface, which is due to the shape of biconcave significantly increased in comparison with a round shape.
The total surface of all human erythrocytes equals 3000-3200 m2, 130 m2 of them fall on the surface of red blood cells, which are at each moment in the capillaries of tissues, and the same on the surface of red blood cells that are in the pulmonary capillaries. The surface of erythrocytes in 1600 times greater than the surface of the body.
The penetration of gas into the tissue, and erythrocytes from erythrocytes in tissues is provided in that the erythrocytes due to the small diameter of the capillary is pushed through them one by one and in that the capillary blood flow is slowed down abruptly.
The second very important function of red blood cells is that they play a major role in maintaining an active reaction of blood. This function is also performed by hemoglobin and red blood cell membrane permeability is provided for the anions and cations of its impermeability and hemoglobin. Therefore, when the pressure of carbon dioxide in the tissues of anions, especially Cl, pass into erythrocytes, which frees part of the cations in the plasma, which connect the incoming carbon dioxide and form salts – bicarbonates and anions received in erythrocytes, consuming part of the cations from hemoglobin to form a neutral salt .
In the lungs, on the contrary, resulting in erythrocytes oxyhemoglobin as a stronger acid consuming cations and anions are liberated in the plasma move back and connected with the cations are cleared after decay of bicarbonate and the removal of carbon dioxide in the lungs. The same happens when you receive the blood of other acids.
The third function of red blood cells – the maintenance of the ionic composition of the blood.
The fourth function of red blood cells – their participation in the water and salt metabolism.
After erythrocytes pass huge amounts of water in it with advanced materials. During the day they passed from 300 to 2000 dm3 water.
In addition, erythrocytes can adsorb toxins, hormones and proteins and degradation products due to their content of the enzymes involved in the enzymatic processes of cleavage of proteins, fats and carbohydrates.