Disease Affected by Sickle-cell disease,<unk> s alter shape and threaten to damage internal organs. Blood diseases involving the<unk> s include: * Anemias (or anaemias) are diseases characterized by low oxygen transport capacity of the blood, because of low<unk>  cell count or some abnormality of the<unk> s or the hemoglobin. :* Iron deficiency anemia is the most common anemia; it occurs when the dietary intake or absorption of iron is insufficient, and hemoglobin, which contains iron, cannot be formed :* Sickle-cell disease is a genetic disease that results in abnormal hemoglobin molecules. When these release their oxygen load in the tissues, they become insoluble, leading to mis-shaped<unk> s. These sickle shaped<unk>  cells are less deformable and viscoelastic, meaning that they have become rigid and can cause blood vessel blockage, pain, strokes, and other tissue damage. :* Thalassemia is a genetic disease that results in the production of an abnormal ratio of hemoglobin subunits. :*Hereditary spherocytosis syndromes are a group of inherited disorders characterized by defects in the<unk> 's cell membrane, causing the cells to be small, sphere-shaped, and fragile instead of donut-shaped and flexible. These abnormal<unk> s are destroyed by the spleen. Several other hereditary disorders of the<unk>  membrane are known. :* Pernicious anemia is an autoimmune disease wherein the body lacks intrinsic factor, required to absorb vitamin B12 from food. Vitamin B12 is needed for the production of hemoglobin. :* Aplastic anemia is caused by the inability of the bone marrow to produce blood cells. :* Pure<unk>  cell aplasia is caused by the inability of the bone marrow to produce only<unk> s. Effect of osmotic pressure on blood cells Micrographs of the effects of osmotic pressure * Hemolysis is the general term for excessive breakdown of<unk> s. It can have several causes and can result in hemolytic anemia. :* The malaria parasite spends part of its life-cycle in<unk> s, feeds on their hemoglobin and then breaks them apart, causing fever. Both sickle-cell disease and thalassemia are more common in malaria areas, because these mutations convey some protection against the parasite. * Polycythemias (or erythrocytoses) are diseases characterized by a surplus of<unk> s. The increased viscosity of the blood can cause a number of symptoms. :* In polycythemia vera the increased number of<unk> s results from an abnormality in the bone marrow. * Several microangiopathic diseases, including disseminated intravascular coagulation and thrombotic microangiopathies, present with pathognomonic (diagnostic)<unk>  fragments called schistocytes. These pathologies generate fibrin strands that sever<unk> s as they try to move past a thrombus. Transfusion<unk> s may be given as part of a blood transfusion. Blood may be donated from another person, or stored by the recipient at an earlier date. Donated blood usually requires screening to ensure that donors do not contain risk factors for the presence of blood-borne diseases, or will not suffer themselves by giving blood. Blood is usually collected and tested for common or serious blood-borne diseases including Hepatitis B, Hepatitis C and HIV. The blood type (A, B, AB, or O) or the blood product is identified and matched with the recipient's blood to minimise the likelihood of acute hemolytic transfusion reaction, a type of transfusion reaction. This relates to the presence of antigens on the cell's surface. After this process, the blood is stored, and within a short duration is used. Blood can be given as a whole product or the<unk> s separated as packed<unk> s. Blood is often transfused when there is known anaemia, active bleeding, or when there is an expectation of serious blood loss, such as prior to an operation. Before blood is given, a small sample of the recipient's blood is tested with the transfusion in a process known as cross-matching. In 2008 it was reported that human embryonic stem cells had been successfully coaxed into becoming<unk> s in the lab. The difficult step was to induce the cells to eject their nucleus; this was achieved by growing the cells on stromal cells from the bone marrow. It is hoped that these artificial<unk> s can eventually be used for blood transfusions. Tests Variations of<unk>  shape, overall termed poikilocytosis. Several blood tests involve<unk> s. These include a<unk>  count (the number of<unk> s per volume of blood), calculation of the hematocrit (percentage of blood volume occupied by<unk> s), and the erythrocyte sedimentation rate. The blood type needs to be determined to prepare for a blood transfusion or an organ transplantation. Many diseases involving<unk> s are diagnosed with a blood film (or peripheral blood smear), where a thin layer of blood is smeared on a microscope slide. This may reveal poikilocytosis, which are variations in<unk>  shape. When<unk> s sometimes occur as a stack, flat side next to flat side. This is known as rouleaux formation, and it occurs more often if the levels of certain serum proteins are elevated, as for instance during inflammation. Separation and blood doping<unk> s can be obtained from whole blood by centrifugation, which separates the cells from the blood plasma in a process known as blood fractionation. Packed<unk> s, which are made in this way from whole blood with the plasma removed, are used in transfusion medicine. During plasma donation, the<unk> s are pumped back into the body right away and only the plasma is collected. Some athletes have tried to improve their performance by blood doping: first about 1 litre of their blood is extracted, then the<unk> s are isolated, frozen and stored, to be reinjected shortly before the competition.<unk> s can be conserved for 5 weeks at , or over 10 years using cryoprotectants) This practice is hard to detect but may endanger the human cardiovascular system which is not equipped to deal with blood of the resulting higher viscosity. Another method of blood doping involves injection with erythropoietin to stimulate production of<unk> s. Both practices are banned by the World Anti-Doping Agency.
Red blood cell
Agranulocyte
Blood cell
Monocyte
White blood cell
Thymocyte
Podocyte
Lymphoblast