Blood Components, Disorders, and WBC Classifications

Vocabulary flashcards derived from lecture transcript notes covering RBC breakdown, polycythemia, anemia, granulocytes, agranulocytes, WBC abnormalities, and leukemia.

Breakdown of Red Blood Cells

The process occurring as an RBC ages and its membrane weakens, leading to its ingestion and destruction by macrophages in the liver and spleen into globin and heme.

Globin

One of the two main components of hemoglobin that is broken down into amino acids, which are used for energy or to create new proteins.

Heme

One of the two main components of hemoglobin that is broken down into iron and bilirubin.

Urochrome

A pigment resulting from the breakdown of hemoglobin that gives urine its yellow color.

Hemolysis

The excessive destruction of red blood cells.

Jaundice

A condition characterized by skin and sclera taking on a yellowish hue, caused by excess bilirubin entering tissues due to excessive RBC destruction, liver disease, or bile duct obstruction.

Physiological Jaundice

A condition occurring in newborns shortly after birth as their immature livers begin the task of clearing bilirubin from the blood.

Polycythemia

A state in which the body has an excess of red blood cells.

Polycythemia Vera

A form of polycythemia caused by an abnormality in the red bone marrow, such as cancer, that triggers the overproduction of red blood cells.

Secondary Polycythemia

A type of polycythemia that occurs when the body attempts to compensate for reduced blood oxygen levels caused by factors such as smoking, lung or heart disease, air pollution, or living at high altitude.

Daily Iron Requirement

The consumption of $5\,mg$ to $20\,mg$ of iron in food each day required to cover the amount lost through urine, feces, and bleeding.

Anemia

A deficiency of red blood cells or hemoglobin.

Iron-Deficiency Anemia

A common type of anemia resulting from an insufficient supply of iron in the diet.

Pernicious Anemia

A nutritional anemia resulting from a lack of vitamin $B_{12}$, typically caused by a lack of intrinsic factor produced in the stomach.

Intrinsic Factor

A chemical produced in the stomach necessary for the body to assimilate vitamin $B_{12}$.

Erythropoietin (EPO)

A hormone that stimulates red bone marrow to create new erythrocytes.

Leukocytes

White blood cells (WBCs), which are the fewest formed elements in blood ($5000$ to $10,000$ per microliter) and serve as the body's defense against infection.

Granulocytes

A classification of white blood cells characterized by obvious cytoplasmic granules and a single multilobular nucleus, comprising neutrophils, eosinophils, and basophils.

Neutrophils

The most abundant white blood cells ($60\%$ to $70\%$ of WBC count), which quickly migrate into tissue spaces to engulf and digest foreign materials.

Band Cells

Young neutrophils whose nucleus looks like a band or a stab wound, also referred to as stab cells.

Polymorphonuclear Leukocytes (PMNs)

Another name for neutrophils, given because the shape of the nucleus varies between individual cells.

Eosinophils

Granulocytes accounting for $2\%$ to $5\%$ of circulating WBCs that are involved in allergic reactions and killing parasites.

Basophils

The least abundant white blood cells ($0.5\%$ to $1\%$ of WBC count), which secrete heparin and histamine.

Heparin

An anticoagulant secreted by basophils that prevents clotting in an infected area so white blood cells can enter.

Histamine

A substance secreted by basophils that causes blood vessels to leak, attracting white blood cells to the site.

Agranulocytes

A classification of white blood cells that lack cytoplasmic granules and multilobular nuclei, comprising lymphocytes and monocytes.

Lymphocytes

The smallest white blood cells ($25\%$ to $33\%$ of WBC count), responsible for long-term immunity.

T Lymphocytes

A type of lymphocyte that directly attacks infected or cancerous cells.

B Lymphocytes

A type of lymphocyte that produces antibodies against specific antigens.

Monocytes

The largest white blood cells ($3\%$ to $8\%$ of WBC count), which circulate in the bloodstream before migrating into tissues to transform into macrophages.

Macrophages

Aggressive phagocytic cells derived from monocytes in tissues that ingest bacteria, cellular debris, and cancerous cells.

Leukopenia

An abnormally low white blood cell count that may result from viral illnesses such as AIDS or lead poisoning.

Leukocytosis

An elevated white blood cell count that usually indicates infection or an allergy.

Differential WBC Count

A blood test that measures the specific count of each individual type of white blood cell.

Complete Blood Cell Count (CBC)

The most commonly performed blood test, which provides information about red blood cells, white blood cells, and platelets.

Leukemia

A cancer of the blood or bone marrow characterized by an extremely high WBC count that crowds out normal bone marrow cells.

Acute Leukemia

A form of leukemia appearing suddenly that involves the rapid increase of immature white blood cells, occurring most commonly in children.

Chronic Leukemia

A slowly developing form of leukemia involving the proliferation of relatively mature but abnormal white blood cells, occurring most often in older people.

Lymphocytic Leukemia

A classification of leukemia involving the rapid proliferation of lymphocytes.

Myeloid Leukemia

A classification of leukemia involving uncontrolled granulocyte production.

Shift to the Left

An increased number of band cells in circulation, typically indicating an active infection.