Term | Definition |
Plasma | Clear, extracellular matrix of blood; roles in clotting, the immune system, & regulation of fluid volume; 55% of bood |
Formed elements | Cell and cell fragments that make up 45% of blood; consists of erythrocytes, leukocytes, & platelets |
Hematocrit | Percentage of cells in a sample of blood; how much oxygen the blood can carry |
Viscosity | Determined by the combination of plasma and blood cells; refers to how thick or sticky a fluid is |
Hemopoiesis | Production of blood |
Hemoglobin | Red pigment that gives blood its color; fills over 1/3 of the interior of an RBC |
Globins | Ribbon-like protein chains in hemoglobin |
Heme | Iron-containing molecule bound to each globin; each can combine with 1 molecule of oxygen |
Erythropoiesis | Producing new erythrocytes; process takes 3-5 days |
Erythropoietin | EPO; hormone secreted by the kidneys that stimulates red bone marrow to begin creating new erythrocytes |
Reticulocyte | Immature form of an erythrocyte; takes 1-2 days to mature |
Hemolysis | Excessive destruction of RBCs |
Polycythemia | Excess of RBCs |
Anemia | Deficiency of RBCs or hemoglobin |
Hemolytic anemia | Results when too many RBCs are being destroyed |
Pernicious anemia | Results from a lack of vitamin B12 |
Leukocytes | WBCs; fewest of the formed elements; 5 types in the body; all contain a neucleus; spend most of their lives in connective tissue |
Granulocytes | WBCs containing a single multilobular nucleus; 3 types include neutrophils, eosinophils, and basophils |
Agranulocytes | WBCs lacking cytoplasmic granules and the neuclei lack lobes; 2 types include lymphocytes and monocytes |
Leukopenia | Abnormally low WBC count |
Leukocytosis | Elevated WBC count |
Platelets | Thrombocytes; 2nd most abundant formed element; key role in hemostasis; live about 7 days |
Hemostasis | Stopping bleeding |
Reaction cascade | Series of reactions in which each depends on the product of the preceding reaction |
Heparin | Anticoagulant secreted by basophils and mast cells |
Thrombus | Unwanted blood clot inside a vessel |
Embolus | Piece of clot breaks off and circulates through the blood stream |
Antigen | Agglutinogen; protein carried on the surface of each red blood cell; 2 types are A & B |
Antibodies | Agglutinins; carried by plasma; against the antigens of other blood types |
Agglutination | Large clumps of antigen-antibody molecules |