Red blood cells, also called erythrocytes or red blood cells, are blood cells essential for oxygenating the body. They transport respiratory gases such as oxygen (O2) and carbon dioxide (CO2). During a blood test, red blood cell levels are particularly monitored.

Location

Like leukocytes (white blood cells) and thrombocytes (platelets), red blood cells are cells circulating in the blood. These cells have this capacity thanks to their particular shape which gives them great elasticity and good resistance.

Form

Red blood cells have a biconcave disc shape with a diameter of about 7 micrometers. This particular form is explained by the absence of a nucleus in the center of the red blood cells.

Colour

Red blood cells are recognizable by their Red color. It is these cells that give the blood the red color. This color explains why red blood cells are also called red blood cells or erythrocytes. This term comes from the Greek words erythros meaning red and Autos meaning cell.

Structure

Red blood cells owe their red color to the presence of hemoglobin within their structure. Hemoglobin is a red pigment, which also has the role of fixing oxygen to transport it to the various tissues of the body.

Synthesis

Erythrocytes are synthesized at the bone marrow. Their formation requires a complex process, which is called erythropoiesis. Red blood cells are produced by several cellular mechanisms from undifferentiated stem cells. This production is governed by a hormone: erythropoietin (EPO), which is often best known for its use as a doping agent.

Name

Erythropoiesis allows the synthesis of several hundred billion red blood cells per day, with a rate between 2 and 3 million per second. This high production rate makes it possible to continuously renew red blood cells at the end of their life. Their lifespan is estimated at 120 days.

Oxygenation of the body

Red blood cells play a key role in the body, ensuring the transport of respiratory gases including oxygen (O2) and carbon dioxide (CO2).

• Transport of oxygen. Red blood cells participate in the oxygenation of the body thanks to hemoglobin. Present in red blood cells, this molecule has the ability to fix and then release oxygen. This gas essential to life is collected in the lungs and then transported to different regions of the body.
• Transport of carbon dioxide. After having transported the oxygen to the tissues, the red blood cells are able to collect the carbon dioxide thanks to an enzyme present on their surface: carbonic anhydrase. The carbon dioxide can thus be returned to the lungs, where it can then be evacuated from the body.

During a blood test, different abnormalities can be seen. These can affect in particular:

• the size of red blood cells, with small (microcytosis) or large (macrocytosis) red blood cells;
• the shape of the red blood cells, for example with the presence of sickle cells;
• the concentration of red blood cells, with levels that are too low or too high in red blood cells.

Anemia

This abnormality is characterized by an abnormally low level of red blood cells. Anemia can have many causes:

• Iron deficiency anemia : A diet low in iron can lead to the formation of small red blood cells. This is called microcytic anemia.
• Vitamin deficiency anemia : A deficiency in vitamin B12 can lead to the formation of large red blood cells. This is called vitamin B12 deficiency anemia or macrocytic anemia.
• Hemorrhagic anemia: A significant loss of blood can be the cause of a deficit in red blood cells.
• Hemolytic anemia : It is due to too rapid destruction of red blood cells.
• Aplastic anemia : It is caused by insufficient synthesis of red blood cells.

Polyglobulas

Unlike anemia, polycythemia is characterized by an abnormally high level of red blood cells. It is due to an excessive production of red blood cells, which can occur in the event of internal or external attacks, or during certain diseases such as polycythemia vera. This chronic disease can lead to the formation of a blood clot (thrombosis).

Sickle cell anemia

This rare genetic disease causes morphological abnormalities in the red blood cells. These have a sickle shape. It is for this reason that sickle cell anemia is also called sickle cell anemia or sickle cell anemia.

Prevention of anemia

It is possible to prevent certain types of anemia. For example, iron deficiency anemia can be prevented by providing sufficient iron. We must also fight against the risk of vitamin deficiency through a healthy and balanced diet.

Treatment of anemia

Some forms of anemia can be treated with certain medications or food supplements. Nutritional supplementation may in particular be recommended in cases of deficiency anemia.

Treatment of severe anemia

A bone marrow transplant or blood transfusion may be needed in severe anemia. It is the same in case of sickle cell anemia.

Hemograms

This examination makes it possible to carry out a qualitative and quantitative measurement things in the blood, including red blood cells. Weak or high red blood cells? Interpreting the results of a blood test helps prevent or diagnose an anomaly. A blood count is sometimes accompanied by a measurement of the sedimentation rate of the red blood cells.

Myelogram

This test measures the production of red blood cells through the study of the bone marrow.

Urine cytobacteriological examination (ECBU)

La presence of red blood cells in the urine can also be evaluated. A high level of red blood cells in the urine can be a sign of disease.

The determination of blood groups is based on the study of red blood cells. Indeed, blood groups are established according to the presence or absence of certain antigens on the surface of the red blood cells. In the ABO system, the AB group corresponds for example to the presence of antigen A and antigen B.