Red blood cells, also called red blood cells or erythrocytes, are blood cells that have a biconcave disk format and are anucleate when they are mature.
Characteristics of Red Blood Cells are:
- Its diameter is approximately seven micrometers, being larger in carbon dioxide-rich blood (venous blood) when compared to oxygen-rich blood (arterial blood).
- They are usually rounded, slightly flattened in the center and very flexible. There are about 4.5 million red blood cells per cubic millimeter of blood.
- The red blood cells of most mammals do not have a nucleus.
- Red blood cells are produced in the bone marrow and their production (erythropoiesis) is stimulated by the glycoprotein hormone called erythropoietin . This hormone is produced after birth mainly by the kidneys, already in the fetal phase it is produced in the liver. Erythropoietin production is mainly affected by low oxygen levels in the tissues.
- Red blood cells are primarily associated with transporting oxygen to all cells in the body. However, they also act in the transport of carbon dioxide and in the plugging of hydrogen ions.
- The functions attributed to red blood cells are only possible thanks to hemoglobin, a substance found inside that cell that is made up of a protein portion and a portion containing iron. This last portion is responsible for binding to oxygen, thus guaranteeing its transport. In addition to its transport function, hemoglobin is also responsible for ensuring the red color of blood.
- The average lifespan of a red blood cell is 120 days. After that period, it is destroyed in the spleen, where approximately ten million red blood cells are destroyed every second. All components of red blood cells are used to make new cells.
- It is estimated that a man has approximately 5,400,000 red blood cells per cubic millimeter of blood, while women have an average of 4,700,00.
- It is important to note that these values vary from person to person and also according to life habits and emotional state. Sometimes the value of red blood cells decreases, leading to a condition commonly known as anemia.
- This health problem can occur, in addition to low synthesis, due to the great destruction of these blood cells, poor cell production, reduction in hemoglobin production or even in cases of blood loss. It is important to note that some anemias have a genetic cause, such as sickle cell anemia.