Red blood cells (also known as erythrocytes or red blood cells) are blood cells responsible for the red color of blood and play an important role in cellular oxygenation of body tissues.
Red blood cell characteristics
Red blood cells are the most common cells in the blood, basically composed of globulin and hemoglobin, protein responsible for the reddish color of blood.
the red blood cells are produced in bone marrow, stimulated by the glycoprotein hormone called erythropoietin. In addition, they have a biconcave disk shape and do not have a nucleus (anucleate) and no DNA when mature.
Red blood cells have a lifespan that lasts about 120 days. After this period, they undergo the process of hemolysis, where they are destroyed in the spleen and liver and their components are used to manufacture new cells.
The diameter of red blood cells is approximately seven micrometers, and may be larger in blood rich in carbon dioxide (venous blood), when compared to blood rich in oxygen (arterial blood).
However, these cells can suffer the phenomenon of macrocytosis or microcytosis, which is the increase or decrease in the size of red blood cells, respectively.
In summary, these are the main characteristics of red blood cells:
- They are anucleate (no nucleus);
- Produced in the bone marrow;
- Contains hemoglobin (responsible for the red color of blood);
- Carry oxygen to every cell in the body;
- Lifespan of red blood cells is 120 days;
- These are the cells with the greatest presence in the blood.
Learn more about the meaning of Hemoglobins.
Red blood cell or erythrocyte function
The main function of red blood cells is related to the transport of oxygen (O2) to all cells in the body. But they also transport carbon dioxide (CO2) and hydrogen ions.
In addition, red blood cells also guarantee the reddish color of the blood. This function, in turn, is performed through hemoglobin, which has a portion of iron in its composition that binds to oxygen, ensuring transport.
The blood has an amount of red blood cells that varies according to the person, their habits and their emotional state. Typically, there are about 5 million red blood cells per cubic millimeter in the blood of a healthy adult male. In women, this figure is approximately 4.5 million.
This counting of red blood cells is performed through the blood count, laboratory exam where blood collection for analysis is taken.
Low and High RBCs
The amount of red blood cells in the blood can be a sign of diseases or conditions that are alarming to a person's health.
low red blood cells
When the amount of red blood cells is low, then the anemia, a disease caused by a low amount of hemoglobin and iron in the blood or due to the great destruction of blood cells.
It is also important to emphasize that some anemias can be caused by genetics, such as sickle cell anemia, a disease characterized by hereditary deformation in the size of red blood cells. This change causes it to become less flexible and more fragile than normal red blood cells, which triggers the rapid destruction of this blood cell.
Learn more about the meaning of Anemia.
high red blood cells
The number of red blood cells usually increases when the individual is in very high places (above 2,500 meters above sea level). The explanation lies in the fact that the organism produces more erythrocytes to oxygenate the other cells of the body, since at high altitudes atmospheric air is scarcer.
High red blood cells occur when they reach a hemoglobin value higher than 17.2 g/dL and 15.1 g/dL for adult men and women, respectively.
If the person is not at high altitudes, the increased red blood cells may represent some type of physiological abnormality.
Among the main diseases and other causes that are related to high hemoglobin are:
- Tumors;
- Pulmonary fibrosis;
- Pulmonary emphysema;
- Dehydration;
- Extreme physical exertion.
Normal levels of red blood cells and hemoglobin in the blood (Hemogram)
| Parameters | Newborn | Baby up to 1 year old | Kids | Women | pregnant | Men |
|---|---|---|---|---|---|---|
| Red blood cells (1012/L) | 4 to 5.6 | 4 to 4.7 | 4.5 to 4.7 | 3.9 to 5.03 | 3.9 to 5.6 | 4.32 to 5.52 |
| Hemoglobin (g/dL) | 13.5 to 19.6 | 11 to 13 | 11.5 to 14.8 | 12 to 16 | 11.5 to 16 | 13.5 to 18 |
Normocytic erythrocytes and Normochromic erythrocytes
The word normocytic is used to name the red blood cells with normal cell size. The word normochromic represents the color normality of the blood cell.
When the result of a blood test shows normocytic or normochromic anemia, it means that there are no abnormalities in the structure and concentration of the red blood cells. So the likely reason the person has anemia is because they've lost a lot of blood all of a sudden.
Red blood cells in urine, what does it mean?
The presence of red blood cells in urine is not normal. If this result is confirmed, it may represent the presence of some diseases, such as:
- sickle cell anemia;
- Tuberculosis;
- Kidney tumor;
- Severe burns.