Erythrocytes: What are they? Characteristics, Functions, Nutrition and Disorders of Red Blood Cells

Its primary function is to transmit oxygen to the whole organism.

Erythrocytes, also called red blood cells, are the most common blood cells. The vertebrate’s primary means of delivering oxygen (O2) to body tissues through the bloodstream through the circulatory system.

Specific characteristics of erythrocytes

  • The erythrocytes are red and consist of a protein called hemoglobin, which contains red iron. That’s why our blood is red.
  • The erythrocytes are round. When these cells are normal, they can be seen as donuts with holes in the center. Hemoglobin is responsible for the round shape of erythrocytes; it increases its surface area, which allows them to transport more oxygen molecules.
  • Finally, erythrocytes are like rubber because they are smooth and bend easily. This gives them the ability to travel quickly in the blood and pass through small vessels to reach various places in the body.
  • Red blood cells are produced inside bones, in the bone marrow. They usually live around 120 days and then die.

Erythrocytes are created in the bone marrow through erythropoiesis before being released into the bloodstream. They go to the spleen, where they decompose at the end of their life. Its useful life is approximately 120 days or four months.


La función principal de los glóbulos rojos es transportar oxígeno a las células del cuerpo y administrar dióxido de carbono a los pulmones.

In the lungs, erythrocytes perform two functions that involve gas exchange. First, the erythrocytes collect the oxygen breathed and take it to other cells, where it is used as food and fuel for the organism.

Then, the carbon dioxide, considered a waste of the body, is thrown by the erythrocytes and then exhaled.

When red blood cells undergo shear stress in the constricted vessels, they release ATP, which causes the ship’s walls to relax and dilate to promote normal blood flow.


When their hemoglobin molecules are deoxygenated, the red blood cells release S-nitrosothiols, which also dilate the blood vessels, thus directing more blood to oxygen-depleted areas of the body.

Red blood cells can also synthesize nitric oxide enzymatically, using L-arginine as a substrate, as do endothelial cells. The exposure of red blood cells to physiological levels of shear stress activates nitric oxide synthase and the export of nitric oxide, which may contribute to the regulation of vascular tone.

Red blood cells can also produce hydrogen sulfide, a signaling gas that acts to relax the walls of vessels. It is believed that the cardioprotective effects of garlic are due to red blood cells converting their sulfur compounds to hydrogen sulfide.

Red blood cells also play a role in the body’s immune response: when there is lysis by pathogens like bacteria, their hemoglobin releases free radicals, which break down the cell wall and the pathogen’s membrane, killing it.

Nutrition and red blood cells

Iron-rich foods help you maintain healthy red blood cells. Vitamins are also necessary to build healthy red blood cells.

These include vitamin E, which is found in foods such as dark green vegetables, nuts and seeds, mango and avocados, vitamins B2, B12, and B3, which are found in foods such as eggs, whole grains, and bananas, available in fortified cereals, dried beans and lentils, orange juice and green leafy vegetables.

Disorders of red blood cells

Blood diseases that involve red blood cells include:

  • Anemias: are diseases characterized by low oxygen transport capacity of the blood due to low red blood cell count or some abnormality of red blood cells or hemoglobin.
  • Sickle cell disease: is a genetic disease that produces abnormal hemoglobin molecules. When these release their oxygen load into the tissues, they become insoluble, resulting in poorly formed red blood cells.
  • Thalassemia: is a genetic disease that results in producing an abnormal proportion of hemoglobin subunits.
  • Syndrome of hereditary spherocytosis: is a group of inherited disorders characterized by defects in the cell membrane of red blood cells, which makes the cells small, spherical, and fragile instead of flexible and donut-shaped.
  • Pernicious anemia: is an autoimmune disease in which the body lacks the intrinsic factor necessary to absorb vitamin B12 from food. Vitamin B12 is required for the production of hemoglobin.
  • Aplastic anemia: is caused by the inability of the bone marrow to produce blood cells.
  • Pure red cell aplasia: is caused by the failure of the bone marrow to produce only red blood cells.
  • Hemolysis: is the general term for the excessive decomposition of red blood cells. It can have several causes and can cause hemolytic anemia.
  • Erythrocytosis: is characterized by an excess of red blood cells. Increasing the viscosity of the blood can cause a series of symptoms.
  • Microangiopathic diseases, including disseminated intravascular coagulation and thrombotic microangiopathies, occur with fragments of pathognomonic red blood cells called schistocytes. These pathologies generate fibrin strands that cut red blood cells as they try to pass a thrombus.