The spleen is an unpaired glandular organ located in the left hypochondrium near the stomach. Although it does not belong to vital formations, its numerous functions provide an answer to the question of why a spleen is needed.
Some features of the spleen
The spleen has an abundant blood supply and is relatively easily damaged during injuries (for example, when hitting the left half abdomen), which often leads to massive, life-threatening bleeding. Because the parenchymal (glandular) structure makes it difficult to repair tears, the organ is usually removed to save the injured person. Other indications for splenectomy (removal) of the spleen may be its infarctions (the appearance of areas of necrosis that occur in some pathologies - liver cirrhosis and malaria), anemia and leukemia (tumor diseases of the blood). A person can live without a spleen (there is even a congenital absence of it, which can be discovered by chance on an ultrasound), but there is nothing unnecessary in the body, and the lack of this gland entails negative consequences.
Functions of the spleen
All manifestations of the activity of the spleen are somehow connected with blood. The main functions of the organ are as follows:
- Hemopoiesis. In the prenatal period, the spleen, together with the liver, is one of the main blood-forming organs. It produces both erythrocytes and cells of the "white" row - leukocytes. By the end of the formation of the fetus, the bulk of this work is shifted to the bone marrow. In the case of suppression of bone marrow hematopoiesis in some diseases, the spleen is able to re-engage in this vital process.
- Immunity. After birth, the bulk of immune cells - lymphocytes and monocytes - continues to form in the spleen, and antibodies are synthesized. In addition, the organ captures viruses, bacteria and toxins from the blood flowing through it, with their subsequent neutralization.
- Blood destruction. The spleen is considered a "graveyard of red blood cells", although it also utilizes white blood cells and platelets. Blood cells that have defects (for example, sickle-shaped red blood cells, which appear in some diseases) or complete their life cycle, are destroyed in the spleen. Their valuable components (for example, iron) are extracted and used for the synthesis of the young generation of cells. In severe anemias, the spleen is sometimes removed to reduce the natural loss of red blood cells.
- Depot function. The spleen always contains some blood supply and about a third of all platelets. If necessary, this volume is used for the needs of the body. Mild pain in the left side, which occurs and quickly passes with prolonged or significant physical exertion (for example, running) is a consequence of the contraction of the spleen, which throws deposited blood into the general bloodstream.
- Endocrine function. There is evidence that the spleen secretes a hormone that stimulates the production of blood cells in the bone marrow.
Although splenectomy is almost never accompanied by serious consequences, in some cases, after this operation, the tension of the immune system decreases, the composition of the blood changes, and the incidence of bacterial infections increases. Understanding why a person needs a spleen makes doctors take care of it and not perform its removal without extreme reasons..