Chapter 12: Blood

Carbon monoxide (CO) poisoning

a serious and sometimes fatal condition in which an odorless gas combines rapidly with hemoglobin and crowds out oxygen; present in the exhaust of gasoline engines

Sickle cell anemia

blood disorder; the shape of the red blood cell is a sickle shape, which makes the red blood cells clump together; chronic blood disease inherited from both parents. The disease causes red blood cells to form in an abnormal crescent shape (see Figure 22-1). These cells carry less oxygen and break easily, causing anemia. The sickling trait, a less serious disease, occurs with inheritance from only one parent. The disease is most prevalent in African Americans, affecting about 1 in 400. The rigid sickling of the red blood cells causes vasoocclusion (blockage) and results in painful crises. A painful crisis is a sudden attack of pain, often occurring in bones and joints in adults and children. Hydroxyurea taken daily prevents painful episodes about 50% of the time. Treatment for sickle cell anemia is b

oxyhemoglobin

hemoglobin combined with oxygen;

erythropoietin

hormone produced by the kidney to accelerate the production of red blood cells

Hematoma

is a localized clotted mass of blood found in an organ, tissue, or space. It is caused by a traumatic injury, such as a blow, that causes a blood vessel to rupture.

Thrombosis

is the formation of a blood clot in a blood vessel. The blood clot formed is called a thrombus (THROM-bus) (Figure 12-6). It is caused by unusually slow blood circulation, changes in the blood or blood vessel walls, immobility, or a decrease in mobility.

stem cells

primal cells common to all multicellular organisms

hematopoiesis

The formation of blood cells; This occurs in the red bone marrow, which is also known as myeloid tissue. All blood cells are produced by the red bone marrow. However, certain lymphatic tissues such as the spleen, tonsils, and lymph nodes produce some white blood cells called agranular leukocytes. All blood cells develop from undifferentiated mesenchymal cells called stem cells or hematocytoblasts.

Leukemia

a cancerous condition in which there is a great increase in the number of white blood cells; a cancerous or malignant condition in which the number of white blood cells is greatly increased. The overabundant immature leukocytes replace the erythrocytes, thus interfering with the transport of oxygen to the tissues. They can also hinder the synthesis of new red blood cells from bone marrow. Common symptoms of leukemia are anemia, fever, night sweats, headache, swollen lymph nodes, and bruising easily. Leukemia may be classified as acute or chronic. Acute forms commonly affect children, progress rapidly, and may be fatal. Chronic forms occur more often in older adults, who may be asymptomatic. It may not cause death. Leukemia is also classified as myelogenous (affecting the bone marrow) or lymphocytic (affecting the lymph nodes). The cause is unknown. Treatment today consists of drug therapy, bone marrow transplants, and radiation therapy, which has given people with leukemia remission periods that last for several years.

leukopenia

a decrease in the normal number of white blood cells (leukocytes)

leukocytosis

an increase in the white blood cell count above 10,000 cells per cubic millimeter

Aplastic anemia

anemia caused by a suppression of the bone marrow; a disease caused by the suppression of the bone marrow. Aplastic anemia has multiple causes. Some of these are idiopathic, meaning they occur sporadically for no known reason. Other causes are secondary, resulting from a previous illness. Acquired causes of the disease may be toxins, drugs, exposure to radiation or chemotherapy, inherited condition, or history of autoimmune disease. In this condition, bone marrow does not produce enough red and white blood cells. Treatment consists of removal of the toxic substances or discontinuation of the drugs, radiation, or chemotherapy. In severe conditions, a bone marrow transplant may be performed.

Cooley's anemia(Thalassemia)

anemia caused by defect in hemoglobin formation; is caused by a defect in hemoglobin formation. It affects people of Mediterranean descent. Treatment consists of antibiotics and frequent red blood cell transfusions. There is no natural way for the body to eliminate iron. The iron from the transfused blood may build up to produce a condition known as "iron overload," which becomes toxic to tissues and organs. Iron overload can result in early death from organ failure. Drugs known as iron chelators can help rid the body of excess iron, preventing or delaying problems related to iron overload.

Monocytes

are formed in bone marrow and the spleen. They assist in phagocytosis and are able to leave the bloodstream to attach themselves to tissues; here they become tissue macrophages, or histiocytes. During inflammation, histiocytes help wall off and isolate the infected area.

Anemia

blood disorder characterized by reduction in red blood cells or hemoglobin; a deficiency in the number and/or percentage of red blood cells and the amount of hemoglobin in the blood. Anemia may result from a large or chronic loss of blood (hemorrhage), or many other causes; it is estimated that there are as many as 400 types of anemia. Because these conditions always cause some hemoglobin deficiency, there is never enough oxygen transported to the cells for cellular oxidation. Consequently, not enough energy is being released. Anemia is characterized by varying degrees of dyspnea, pallor, palpitation, and fatigue.

Pernicious anemia

caused by decrease of vitamin b12 or lack of intrinsic factor in the stomach; Pernicious anemia is seen in association with some autoimmune endocrine diseases. The intrinsic factor produced by the stomach mucosa is necessary for the absorption and utilization of vitamin . Vitamin and folic acid are necessary for the development of mature red blood cells. Symptoms such as dyspnea, pallor, and fatigue are present, along with specific neurologic changes. Treatment for pernicious anemia involves medicating with vitamin , by injection, pills or nasal spray.

T lymphocytes

cell synthesized in the thymus gland

myeloblasts

cells that synthesize granulocytes in bone marrow

pyrogens

chemical released when there is inflammation; pyrogens circulate to the hypothalamus and affect the temperature control center

Iron-deficiency anemia

condition that results from lack of adequate amounts of iron in the diet; a condition that often exists in women, children, and adolescents. It is caused by a deficiency of adequate amounts of iron in the diet. This leads to insufficient hemoglobin synthesis in the red blood cells. The condition is easily alleviated by ingestion of iron supplements and green, leafy vegetables that contain the mineral iron.

Thrombocytopenia

decrease in the number of platelets; a blood disease in which the number of platelets is decreased. In this condition, blood will not clot properly.

Basophils

leukocyte cell that is activated during an allergic reaction or inflammation; produces histamine and heparin;

plasma

liquid part of blood that contains corpuscles; Blood is made up of plasma (PLAZ-mah), the liquid portion of blood without its cellular elements. Serum is the name given to plasma after a blood clot is formed

Multiple myeloma

malignant neoplasm of plasma cells or B lymphocytes; malignant neoplasm of plasma cells or B lymphocytes. The plasma cells multiply abnormally in the bone marrow, causing weakness in the bone that leads to pathologic fractures and bone pain. Overgrowth of plasma cells leads to a decrease in other blood components. The prognosis is poor; chemotherapy and radiation are not effective.

Neutrophils

many-lobed white blood cell that phagocytizes bacteria; sometimes called "polys"; also called polymorphonuclear leukocytes, phagocytize bacteria with lysosomal enzymes. Phagocytosis is a process that surrounds, engulfs, and digests harmful bacteria.

Embolism

obstruction of a blood vessel by a circulating blood clot, fat globule, air bubble, or piece of tissue; a condition where an embolus is carried by the bloodstream until it reaches an artery too small for passage. An embolus is a substance foreign to the bloodstream (Figure 12-5). It may be air, a blood clot, cancer cells, fat, bacterial clumps, a needle, or even a bullet that was lodged in tissue and breaks free.

Inflammation

occurs when tissue reacts to chemical or physical trauma or invasion of pathogenic microorganisms; characterized by pain, heat, redness, and swelling

hemoglobin

oxygen-carrying pigment of the blood; made of a protein molecule called globin and an iron compound called heme. A single blood cell contains several million molecules of hemoglobin. Hemoglobin is vital to the function of red blood cells, allowing them to transport oxygen to the tissues and some carbon dioxide away from the tissues. Normal hemoglobin count for men is 14 to 18 g, and for women 12 to 16 g per 100 mL.

thrombocytes

platelet; part of the megakaryocyte cells necessary for blood clotting

Septicemia

presence of pathogenic organisms in the blood; describes the presence of pathogenic (disease-producing) organisms or toxins in the blood. In almost all cases of septicemia the individual must be hospitalized. Treatment is with intravenous antibiotics and therapy to support any other organ dysfunction.

Hemostasis

process of controlling or stopping bleeding; This can be accomplished by vasoconstriction (initiated by the chemical serotonin released by the platelets), external pressure to block the flow of blood, or the formation of a blood clot.

pus

product of inflammation; a cream-colored liquid that is a combination of dead tissue, dead and living bacteria, dead white blood cells, and blood plasma

erythrocytes

red blood cell; Erythrocytes contain a red pigment called hemoglobin, which provides their characteristic color. In the capillaries of the lung, erythrocytes pick up oxygen from the inspired air.

Hemophilia

sex-linked, hereditary bleeding disorder occurring mostly in males but transmitted by females; characterized by a prolonged clotting time and abnormal bleeding; a hereditary disease in which the blood clots slowly or abnormally. This causes prolonged bleeding with even minor cuts and bumps. Although sex-linked hemophilia occurs mostly in males, it is transmitted genetically by females to their sons. Treatment of the several types of hemophilia varies depending on the severity of the condition. Hemophilia A is caused by lack of blood factor VIII. Mild hemophilia A treatment involves an injection of the hormone desmopressin to stimulate a release of more of the clotting factor. Hemophilia B is caused by lack of blood factor IX. Moderate to severe hemophilia A or hemophilia B requires an injection of the clotting factor. A person with hemophilia is taught to avoid trauma, if possible, and report promptly any bleeding, no matter how slight.

hemolysis

the bursting of red blood cells; This sometimes occurs as a result of a blood transfusion reaction or other disease processes.

Thrombocytes

the smallest of the solid components of blood. They are ovoid-shaped structures, synthesized from the larger megakaryocytes in red bone marrow. Thrombocytes are not cells but fragments of the megakaryocyte's cytoplasm. The normal blood platelet count ranges from 250,000 to 450,000/ul venous blood of blood. Platelets function in the initiation of the blood clotting process.

Polycythemia

too many red blood cells; a condition in which too many red blood cells are formed. This can be a temporary condition that occurs at high altitudes, where less oxygen is present. Another type is polycythemia vera; the cause is unknown. The increase in the number of red blood cells causes a thickening of the blood, with possible blood clot formation. Treatment for this condition is phlebotomy (removal of approximately 1 pint of blood), low-dose aspirin, and/or medication that suppresses the bone marrow's ability to produce blood cells.

Eosinophils

white blood cell that increases in great numbers in allergic conditions; phagocytizes the remains of the antibody-antigen reaction

leukocytes

white blood cell; They are called white blood cells because they lack pigmentation. They are larger than the erythrocytes and granular (with a grainy appearance) or agranular (no grainy appearance). Leukocytes are manufactured in both red bone marrow and lymphatic tissue. Leukocytes are the body's natural defense against injury and disease.

B lymphocytes

white blood cells synthesized in the bone marrow; help form antibodies

Erythropoiesis

formation or development of red blood cells; occurs in the red bone marrow of essentially all bones, until adolescence. As one grows older, the red marrow of the long bones is replaced by fat marrow; erythrocytes are thereafter formed only in the short and flat bones. The rate of erythropoiesis is influenced by erythropoietin, a hormone produced largely in the kidneys. When the number of circulating red blood cells decreases or when the oxygen transported by the blood diminishes, an unidentified sensor in the kidney detects the change and the production of erythropoietin is increased. This substance is then transported through the plasma to the bone marrow, where it accelerates the production of red blood cells. Erythrocytes come from stem cells in the red bone marrow called hemocytoblasts. As the hemocytoblast matures into an erythrocyte, it loses its nucleus and cytoplasmic organelles. The hemocytoblast also becomes smaller, gains hemoglobin, develops a biconcave shape, and enters the bloodstream. To aid in erythropoiesis, vitamin b12, folic acid, copper, cobalt, iron, and proteins are needed. Because erythrocytes are enucleated (contain no nucleus), they only live about 120 days. Destruction occurs as the cells age, rendering them more vulnerable to rupturing. They are broken down by the spleen and liver. Hemoglobin breaks down into globin and heme. Most of the iron content of heme is used to make new red blood cells; the balance of the heme group is degraded to bilirubin and is stored in the liver. The normal count of red blood cells ranges from 4.5 to 6.2 million/µL venous blood for men and 4.2 to 5.4 million/µL venous blood for women.