Hematology: Blood Cells and Measurements

• Emia/Hemia means a condition of blood.
• Penia means decrease or deficiency.
• Poiesis means formation or production.
• Myel/o refers to bone marrow.
• Hem/o and hemat/o refer to blood.
• Erythr/o and erythrocyt/o refer to red blood cells.
• Leuk/o and lekocyt/o refer to white blood cells.
• Lymph/o and Lymphocyt/o refer to lymphocytes.
• Thromb/o refers to a blood clot.
• Thrombocyt/o refers to a platelet or thrombocyte.
• Immun/o refers to immunity or immune system.

Blood Tests and Measurements

• Red blood cell count (RBC) measures the number of red blood cells in blood.
• White blood cell count (WBC) measures the number of white blood cells in blood.
• Differential count (Diff) measures the relative percentage of different types of leukocytes.
• Hematocrit (Ht, Hct, crit) measures the relative percentage of packed red cells in a given blood volume.
• Packed cell volume (PCV) is another term for hematocrit.
• Hemoglobin (Hb, Hgb) measures the amount of hemoglobin in a cell.
• Mean corpuscular volume (MCV) measures the volume of the average red cell.
• Mean Corpuscular Hemoglobin (MCH) measures the average amount of hemoglobin per each RBC.
• Mean Corpuscular Hemoglobin Concentration (MCHC) calculates the average hemoglobin concentration in each red blood cell.
• Erythrocyte sedimentation rate (ESR) measures the rate of settling of erythrocytes, used to detect infection or inflammation.
• Complete blood count (CBC) is a series of tests including cell counts, hematocrit, hemoglobin, and cell volume measurements.

Terms

• Agglutination is the clumping of red blood cells.
• Bilirubin is a pigment from the breakdown of hemoglobin.
• Complement is a group of plasma enzymes that interacts with antibodies.
• Corpuscle is a small mass or body.
• Gamma globulin is the fraction of blood plasma that contains antibodies.
• Hemopoietic stem cell is a primitive bone marrow cell that gives rise to all varieties of blood cells.
• Heparin is an anticoagulant substance found throughout the body that inhibits blood coagulation.
• Megakaryocyte is a large bone marrow cell that fragments to release platelets.
• Plasmin is an enzyme that dissolves clots, also known as fibrinolysin.
• Thrombin is the enzyme derived from prothrombin that converts fibrinogen to fibrin.

Medications and Procedures

• Anticoagulant prevents or delays blood coagulation.
• Antihistamine counteracts the effects of histamine and is used to treat allergic reactions.
• Apheresis is a procedure where blood is withdrawn, a portion is separated, and the remainder is returned to the donor.
• Autologous blood is a person's own blood, donated in advance of surgery for transfusion if needed.
• Cryoprecipitate is a sediment obtained by cooling; the fraction obtained by freezing blood plasma contains clotting factors.
• Desensitization is the treatment of allergy by small injections of the offending allergen, increasing antibody production.
• Homologous blood is blood from animals of the same species, such as human blood used for transfusion.
• Immunosuppression is the depression of the immune response.
• Protease inhibitor is an anti-HIV drug that inhibits an enzyme the virus needs to multiply.

Blood Tests Acronyms

• APPT (Activated Partial Thromboplastin Time) measures the time required for clot formation.
• BT (Bleeding Time) measures the capacity of platelets to stop bleeding after a standard skin incision.
• PTT (Partial Thromboplastin Time) evaluates clotting factors and is similar to APPT but less sensitive.
• PT/Pro Time indirectly measures Prothrombin.
• TT (Thrombin Time or Thrombin Clotting Time) measures how quickly a clot forms.