noun, plural: blood cells
Any of the cells in blood, i.e. a red blood cell (erythrocyte) or a white blood cell (leukocyte), and sometimes a platelet
Blood is the circulating fluid in the body of eukaryotic animals. A mammalian blood is comprised typically of 55% plasma and 45% cellular elements (blood cells and platelets). Blood cells may be classified as either a red blood cell (a mature red blood cell is also called an erythrocyte) or a white blood cell (a mature white blood cell also called a leukocyte). The platelet (also referred to as thrombocyte) is sometimes considered as a blood cell. However, it is a cellular fragment that pinched off from a larger cell in the bone marrow and is lacking a nucleus. All of the three cell types arise from multipotent stem cells in red bone marrow. The red blood cells are blood cells that carry oxygen throughout the body. The white blood cells are blood cells involved in the immune reactions, fighting off infections and removing cellular debris. The platelets are involved in blood clot formation to prevent bleeding when there is a tissue injury. The correct balance between each cell type must be maintained for the body to remain healthy.