Function of red blood cells (physiological function of red blood cells)
Red blood cells are derived from primitive hematopoietic stem cells of red bone marrow. Mature erythrocytes are double-concave discs without nuclei, and contain hemoglobin in the cytoplasm, also known as hemoglobin.
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Red blood cells live for about 120 days, and aging red blood cells are phagocytized by macrophages in the spleen. When hemoglobin is released, as in plasma, it loses its physiological function.
The physiological function of red blood cells is reflected in hemoglobin. Its main function is to transport oxygen and dioxide and regulate the pH of the blood.
Reduced hemoglobin does not combine with oxygen, so venous blood is dark red; oxyhemoglobin binds oxygen, so arterial blood is bright red.
1. Patients with anemia have less hemoglobin and less oxygenated hemoglobin, so they are pale, not cyanotic but hypoxic.
2. The skin, lips, and nail beds of patients with severe hypoxia are blue-purple, which is called cyanosis.
3. Plateau red is a kind of environmental hypoxia. There are a lot of red blood cells in the body, so the face is cyanotic, but the body is not hypoxic.
4. Carbon monoxide poisoning, carbon monoxide and hemoglobin form carboxyhemoglobin, the color is cherry red.
5. Potassium cyanide poisoning, the cyanide hemoglobin formed is also cherry red.
6. Nitrite poisoning forms methemoglobin, loses the ability to carry oxygen, and the skin turns blue-gray.