Blood and Immunity

Erythrocyte (red blood cell)

-5 million per ml

-tiny (7 mcm diameter), biconcave disk without nucleus (anuclear)

Leukocyte (white blood cell)

-5,000 to 10,000

-larger than red cell with prominent nucleus that may be segmented (granulocyte) or unsegmented (agranulocyte); types vary in staining properties

Platelet (thrombocyte)

-150,000 to 450,000

-fragment of large cell (megakaryocyte)

Erythrocyte (red blood cell

carries oxygen bound to hemoglobin; also carries some carbon dioxide and buffers blood

Leukocyte (white blood cell)

immunity; protects against pathogens and destroys foreign matter and debris; located in blood, tissues, and lymphatic system

Platelet (thrombocyte)

hemostasis; forms a platelet plug and starts blood clotting (coagulation)

Neutrophil

-54 to 62 percent

-phagocytosis

Eosinophil

-1 to 3 percent

-allergic reactions; defense against parasites

Basophil

-less than 1 percent

-allergic reactions

Lymphocyte

-25 to 38 percent

-immunity (T cells and B cells)

Monocyte

-3 to 7 percent

-phagocytosis

agranulocyte

white blood cell that does not have visible granules in its cytoplasm; agranulocytes include lymphocytes and monocytes

albumin

simple protein found in blood plasma

antibody

protein produced in response to and interacting specifically with an antigen

antigen

substance that induces the formation of an antibody

antigen-presenting cell (APC)

immune cell that takes in a foreign antigen, processes it, and presents it on the cell surface in combination with the body’s own proteins, thus activating a T cell; examples are dendritic cells and macrophages, which are descendants of monocytes

B cell

a lymphocyte that matures in bone marrow and is active in producing antibodies; B lymphocyte

band cell

an immature neutrophil with a nucleus in the shape of a band; also called a stab cell; band cell counts are used to trace infections and other diseases

basophil

granular leukocyte that stains strongly with basic dyes; active in allergic reactions

blood

the fluid that circulates in the cardiovascular system

coagulation

blood clotting

cross-matching

testing the compatibility of donor and recipient blood in preparation for a transfusion; donor red cells are mixed with recipient serum to look for an immunologic reaction; similar tests are done on tissues before transplantation

electrolyte

substance that separates into charged particles (ions) in solution; a salt; term also applied to ions in body fluids

eosinophil

granular leukocyte that stains strongly with acidic dyes; active in allergic reactions and defense against parasites

erythrocyte

red blood cell

erythropoietin (EPO)

hormone produced in the kidneys that stimulates red blood cell production in the bone marrow; this hormone is now made by genetic engineering for clinical use

fibrin

protein that forms a clot in the blood coagulation process

fibrinogen

the inactive precursor of fibrin

formed elements

the cellular components of blood

gamma globulin

fraction of the blood plasma that contains antibodies; given for passive transfer of immunity

granulocyte

white blood cell that has visible granules in its cytoplasm; granulocytes include neutrophils, basophils, and eosinophils

hemoglobin (Hb, Hgb)

iron-containing pigment in red blood cells that transports oxygen

hemostasis

stoppage of bleeding

immunity

state of being protected against a disease

immunoglobulin (Ig)

an antibody; immunoglobulins fall into five classes, each abbreviated with a capital letter: IgG, IgM, IgA, IgD, IgE

leukocyte

a white blood cell

lymphocyte

an agranular leukocyte active in immunity (T and B cells); found in both the blood and in lymphoid tissue

megakaryocyte

a large bone marrow cell that fragments to release platelets

monocyte

an agranular phagocytic leukocyte

neutrophil

a granular leukocyte that stains weakly with both acidic and basic dyes; the most numerous of the white blood cells; a type of phagocyte

phagocytosis

the engulfing of foreign material by white blood cells

plasma

the liquid portion of the blood

plasma cell

a mature form of a B cell that produces antibodies

platelet

a formed element of the blood that is active in hemostasis; a thrombocyte

serum

the fraction of the plasma that remains after blood coagulation; it is the equivalent of plasma without its clotting factors

T cell

a lymphocyte that matures in the thymus and attacks foreign cells directly; T lymphocyte

thrombocyte

a blood platelet

-emia -hemia

condition of blood

-penia

decrease in, deficiency of

-poiesis

formation, production

polycythemia

increase of cells (cyt) in the blood

cytopenia

deficiency of cells

hemopoiesis

production of blood cells

myel/o

bone marrow

hem/o, hemat/o

blood

erythr/o, erythrocyt/o

red blood cell

leuk/o, leukocyt/o

white blood cell

lymph/o, lymphocyt/o

lymphocyte

thromb/o

blood clot

thrombocyt/o

platelet, thrombocyte

immun/o

immunity, immune system

myelogenous

originating in bone marrow

hemopathy

any disorder of blood

erythroblast

immature red blood cell

leukocytosis

increase in the number of leukocytes in the blood

lymphocytic

pertaining to lymphocytes

thrombolytic

dissolving a blood clot

thrombopoiesis

formation of platelets

immunization

production of immunity

azot/o

nitrogenous compounds

calc/i

calcium (symbol Ca)

ferr/o, ferr/i

iron (symbol Fe)

sider/o

iron

kali

potassium (symbol K

natri

sodium (symbol Na)

ox/y

oxygen (symbol O)

azoturia

increased nitrogenous compounds in the urine (-uria)

calcification

deposition of calcium salts

ferrous

pertaining to or containing iron

sideroderma

deposition of iron into the skin

hyperkalemia

excess of potassium in the blood

natriuresis

excretion of sodium in the urine (ur/o)

hypoxia

deficiency of oxygen in the tissues

red blood cell count (RBC)

number of red blood cells per microliter of blood

white blood cell count (WBC)

number of white blood cells per microliter of blood

differential count (Diff)

relative percentage of the different types of leukocytes

hematocrit (Ht, Hct, crit)

relative percentage of packed red cells in a given volume of blood

packed cell volume (PCV)

hematocrit

hemoglobin (Hb, Hgb)

amount of hemoglobin in g/dL (100 mL) of blood

mean corpuscular volume (MCV)

volume of an average red cell

mean corpuscular hemoglobin (MCH)

average weight of hemoglobin in red cells

mean corpuscular hemoglobin concentration (MCHC)

average concentration of hemoglobin in red blood cells

erythrocyte sedimentation rate (ESR)

rate of erythrocyte settling per unit of time; used to detect infection or inflammation

complete blood count (CBC)

series of tests including cell counts, hematocrit, hemoglobin, and cell volume measurements

activated partial thromboplastin time (APTT)

measures time required for clot formation; used to evaluate clotting factors and monitor heparin therapy

bleeding time (BT)

measures capacity of platelets to stop bleeding after a standard skin incision

partial thromboplastin time (PTT)

evaluates clotting factors; similar to APTT, but less sensitive

prothrombin time (PT, pro time)

indirectly measures prothrombin; used to monitor anticoagulant therapy; also called Quick test

thrombin time (thrombin clotting time) TT (TCT)

measures how quickly a clot forms

acquired immunodeficiency syndrome (AIDS)

immune system failure caused by infection with HIV (human immunodeficiency virus); the virus infects certain T cells and thus interferes with immunity