Module 4 Ch18 Part 3

macrophage

phagocytic cell of the myeloid lineage; a matured monocyte

megakaryocyte

bone marrow cell that produces platelets

memory cell

type of B or T lymphocyte that forms after exposure to a pathogen

monocytes

agranular leukocytes of the myeloid stem cell line that circulate in the bloodstream; tissue monocytes are macrophage

myeloid stem cells

type of hematopoietic stem cell that gives rise to some formed elements, including erythrocytes, megakaryocytes that produce platelets, and a myeloblast lineage that gives rise to monocytes and three forms of granular leukocytes (neutrophils, eosinophils, and basophils)

natural killer (NK) cells

cytotoxic lymphocytes capable of recognizing cells that do not express “self” proteins on their plasma membrane or that contain foreign or abnormal markers; provide generalized, nonspecific immunity

neutrophils

granulocytes that stain with a neutral dye and are the most numerous of the leukocytes; especially active against bacteria

oxyhemoglobin

molecule of hemoglobin to which oxygen is bound

packed cell volume (PCV)

(also, hematocrit) volume percentage of erythrocytes present in a sample of centrifuged blood

plasma

in blood, the liquid extracellular matrix composed mostly of water that circulates the formed elements and dissolved materials throughout the cardiovascular system

plasmin

blood protein active in fibrinolysis

platelet plug

accumulation and adhesion of platelets at the site of blood vessel injury

platelets

(also, thrombocytes) one of the formed elements of blood that consists of cell fragments broken off from megakaryocytes

pluripotent stem cell

stem cell that derives from totipotent stem cells and is capable of differentiating into many, but not all, cell types

polycythemia

elevated level of hemoglobin, whether adaptive or pathological

polymorphonuclear

having a lobed nucleus, as seen in some leukocytes

positive chemotaxis

process in which a cell is attracted to move in the direction of chemical stimuli

red blood cells (RBCs)

(also, erythrocytes) one of the formed elements of blood that transports oxygen

reticulocyte

immature erythrocyte that may still contain fragments of organelles

Rh blood group

blood-type classification based on the presence or absence of the antigen Rh on the erythrocyte membrane surface

serum

blood plasma that does not contain clotting factors

sickle cell disease

(also, sickle cell anemia) inherited blood disorder in which hemoglobin molecules are malformed, leading to the breakdown of RBCs that take on a characteristic sickle shape

T lymphocytes

(also, T cells) lymphocytes that provide cellular-level immunity by physically attacking foreign or diseased cells

thalassemia

inherited blood disorder in which maturation of RBCs does not proceed normally, leading to abnormal formation of hemoglobin and the destruction of RBCs

thrombin

enzyme essential for the final steps in formation of a fibrin clot

thrombocytes

platelets, one of the formed elements of blood that consists of cell fragments broken off from megakaryocytes

thrombocytopenia

condition in which there are too few platelets, resulting in abnormal bleeding (hemophilia)

thrombocytosis

condition in which there are too many platelets, resulting in abnormal clotting (thrombosis)

thrombopoietin

hormone secreted by the liver and kidneys that prompts the development of megakaryocytes into thrombocytes (platelets)

thrombosis

excessive clot formation

thrombus

aggregation of fibrin, platelets, and erythrocytes in an intact artery or vein

tissue factor

protein thromboplastin, which initiates the extrinsic pathway when released in response to tissue damage

totipotent stem cell

embryonic stem cell that is capable of differentiating into any and all cells of the body; enabling the full development of an organism

transferrin

plasma protein that binds reversibly to iron and distributes it throughout the body

universal donor

individual with type O− blood

universal recipient

individual with type AB+ blood

vascular spasm

initial step in hemostasis, in which the smooth muscle in the walls of the ruptured or damaged blood vessel contracts

white blood cells (WBCs)

(also, leukocytes) one of the formed elements of blood that provides defense against disease agents and foreign materials