| Term | Definition |
| Hematopoietic system | consists of blood (cells and plasma), bone marrow, the liver, the spleen, and the kidneys |
| Pluripotent stem cell | cell from which the various types of blood cells can form |
| Hematopoiesis | process through which pluripotent stem cells differentiate into various types of blood cells. |
| Extramedullary hematopoiesis | occurs outside the bone marrow in the liver, spleen, lymph nodes, and thymus; occurs in the fetus |
| Intramedullary hematopoiesis | developing bone marrow is the primary site of blood cell production and extramedullary hematopoiesis greatly diminishes, occurring mostly in the liver and spleen (after 4th month of fetal development). |
| Erythropoietin | hormone responsible for red blood cell production |
| Plasma | thick, pale yellow fluid that makes up the liquid part of the blood; transports the cellular components of blood and dissolved nutrients throughout the body |
| Erythrocyte | red blood cell; concave disc that does not have a nucleus when mature. |
| Hemoglobin | oxygen-bearing molecule in the red blood cells. It is made up on iron-rich red pigment called heme and a protein called globins |
| Oxygen Transport | the greater the number of red blood cells, the greater the potential oxygen carrying capacity |
| Bohr effect | phenomenon in which a decrease in pCO2/acidity causes an increase in the quantity of oxygen that binds with the hemoglobin and conversely, an increase in pCO2/acidity causes the hemoglobin to give up an quantity of oxygen |
| 2, 3-diphosphoglycerate (2, 3-DPG) | chemical in the RBC that affects hemoglobin’s affinity for oxygen. |
| Erythropoiesis | the process of producing RBC |
| Hemolysis | destruction of RBCs |
| Sequestration | trapping of RBCs by an organ such as the spleen |
| Hematocrit | the packed cell volume of RBCs per unit of blood |
| Leukocyte | white blood cells; circulate through the bloodstream and tissues, providing protection from foreign invasion |
| Marginated leukocytes | large population of leukocytes that attach to the walls of the blood vessels (adhesion) |
| Demargination | leukocytes that return to the circulating pool in response to stress, corticosteroids, seizures, epinephrine, and exercise (diapedesis). |
| chemotaxis | movement of WBCs on response to chemical signals |
| phagocytosis | process in which WBCs engulf and destroy an invader |
| leukopoiesis | process though which stem cells differentiate into the WBC’s immature forms: myeloblasts, monoblasts, and lymphoblasts |
| Granulocytes | WBCs named for the granules they contain, form from stem cells that differentiate in the bone marrow in response to hormonal stimulation |
| Basophils | absorb basic stains and show blue granules. Primarily function in allergic reactions – their granules store all of the histamine in the circulating blood |
| Eosinophils | highly specialized; inactivate the chemical mediators of acute allergic reactions, modulating the anaphylactic response |
| major basic protein (MBP) | larvicidal peptide released by eosinophils in conjunction with an antibody release shown to fight parasitic infections |
| Neutrophils | primary function is to fight infection; they leave the blood stream by diapedesis and engulf and kill microorganisms that have invaded the body |
| Neutropenia | low neutrophils count |
| Monocytes | after their initial phase of maturation they are released into the circulation and can remain there as circulating monocytes or migrate to distant sites to further mature into free or fixed tissue macrophages |
| Lymphocytes | primary cells involved in the body’s immune response |
| T cells | mature in the thymus gland; they are responsible for developing cell mediated immunity |
| B cells | produce antibodies to combat infection (humoral immunity). Originate in the bone marrow and migrate to peripheral lymphatic tissues |
| Autoimmune Disease | condition in which the body makes antibodies against it’s own tissues; these antibodies may be specific to certain organs or involve virtually every tissue type. |
| Inflammatory Process | a nonspecific defense mechanism that wards off damage from microorganisms or trauma. It attempts to localize the damage while destroying the source, at the same time facilitating repair of the tissues |
| Thrombocytes | blood platelet; small fragments of large cells called megakaryocytes; come from undifferentiated stem cells in the bone marrow |
| thrombocytopenia | condition in which there are too few platelets |
| thrombocytosis | too many platelets, condition causes abnormal clotting, plugs in vessels, and emboli that may travel to the extremities, heart, lungs, or brain |
| hemostasis | combined three mechanism that wok to prevent or control blood loss: vascular spasms, platelet plugs; stable fibrin blood clots {coagulation}. |
| Fibrinolysis | process through which plasmin dismantles a blood clot |
| Thrombosis | clot formation, which is extremely dangerous when it occurs in coronary arteries or cerebral vasculature |
| Blood transfusion | transplantation of blood or a component of blood from one person to another, accomplished by IV infusion |
| Antigens | protein on the surface of a donor’s RBCs that the patient’s body recognizes as “not self.” |
| Polycythemia | excess of red blood cells |
| Anemia | an inadequate number of RBC or inadequate hemoglobin within the RBCs. |
| Sickle cell anemia (disease) | an inherited disorder of RBC production, so named because the RBCs become sickle-shaped when oxygen levels are low |
| Polycythemia | abnormally high hematocrit, due to excess production of RBCs. Can occur secondary to dehydration and increases the patient’s risk of thrombosis. |
| Leukopenia | too few white blood cells |
| Leukocytosis | too many white blood cells |
| Neutropenia | reduction on the number of neutrophils. |
| Leukemia | cancer of the hematopoietic cells |
| Lymphoma | cancer of the lymphatic system |
| Thrombocytosis | abnormal increase in the number of platelets |
| Thrombocytopenia | abnormal decrease in the number of platelets |
| Hemophilia | blood disorder in which one of the proteins necessary for blood clotting is missing or defective |
| von Willebrand’s disease | condition in which the vWF component of factor VII is deficient. |
| Disseminated Intravascular Coagulation (DIC) | disorder of coagulation caused by systemic activation of the coagulation cascade |
| Multiple myeloma | cancerous disorder of plasma cells |
