Wiesław W. Jędrzejczak: Krew. Bezcenna tkanka

By blood, we usually mean only peripheral blood: the red fluid found in vessels and composed of blood cells and plasma. In reality, the term encompasses all tissue, including the organ that produces blood cells, the bone marrow (in adults, located in the flat bones). Interestingly, bone marrow is formed from single cells called hematopoietic stem cells. Under ideal conditions, one such cell is enough to produce the entire bone marrow and maintain its continuous function. This requires the production of approximately half a billion cells per day in an adult. This is also the same number of blood cells consumed daily. Blood serves three main functions in the body: transport, clotting, and immunity. The latter is particularly important. We live in a world where many microorganisms perceive us as food. We exist only as long as we are able to defend ourselves against them. The first line of defense is provided by the neutrophils and monocyte-derived macrophages contained in the blood. The second line of defense consists of various types of lymphocytes and their products, called antibodies. Blood unites our body and protects its integrity. It is invaluable to us. Professor Wiesław Jędrzejczak is a physician and head of the Department and Clinic of Hematology, Oncology, and Internal Medicine at the Medical University of Warsaw. His research and clinical practice include hematology, transplantology, and nuclear medicine. He is a pioneer in bone marrow transplant surgery in Poland.