Medical Terminology Ch. 13
Terms
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- Primary functions of blood? (3)
- To maintain constant environment for other living tissues of the body. Also transports foods, gases, and wastes to and from the cells of the body. Also contains proteins and white blood cells that fight infection, and platelets that help blood to clot.
- Blood is composed of ___ suspended in ___.
- cells (formed elements); plasma (clear, straw-colored liquid)
- Cells constitute ___% of blood volume and include ___, ___, and ___. The remaining percentage is made of ___.
- 45%; erythrocytes (red), leukocytes (white), and platelets (thrombocytes -- clotting cells); plasma (solution of water, proteins, sugar, salts, hormones, and vitamins.
- What are stem cells?
- cells that form white and red blood cells. Under the influence of proteins and bone marrow, they change their size and shape to become differentiated (become larger and nucleus shrinks).
- Why are red blood cells concave? RBC's contain ___ which is composed of ___ and ___. What does this do?
- Allows for larger surface area so that absorption and release of gases can take place; Hemoglobin; composed of heme (iron-containing pigment) and globin (protein). It enables the RBC to carry oxygen. Combo of hemoglobin and oxygen produces red color.
- RBCs originate where? What stimulates their production? How long does an average RBC stay active? What breaks them down?
- In bone marrow; erythropoietin; 120 days; macrophages break down 2 to 10 million each second.
- Are RBCs or WBCs more numerous? How many types of white are there? What are the 2 categories?
- Red; 5; granulocytes (mulitlobed nuclei) and agranulocytes
- 3 types of granulocytes? Explain each of the 3.
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Neutrophils - - phagocytes - - accumulate at site of infection and ingest bacteria. don't stain.
Basophils - - secrete histamine (allergic reaction) and heparin (anticoagulant). Stain dark blue with base dye.
Eosinophils - - increase in number in response to allergic reaction. Stain red with acid dye. - What are the 2 types of agranulocytes? Explain both.
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Monocytes - - phagocytes - - digest bacteria and tissue debris
Lymphocytes - - some produce antibodies. Some are phagocytes. Important in immune response. - Immune response: what is it? Allow us to do what?
- Defense mechanism that produces antibodies to destroy antigens. Allows us to develop resistance to a disease or harmful agents.
- B-cell lymphocytes do what?
- Produce antibodies to antigens - - HUMORAL IMMUNITY. They convert to plasma cells and secrete antibodies. Antibody reacts with the antigen and destroys it.
- T-cell lymphocytes mature where? Do what?
- Mature in thymus gland. Act directly on antigens - - poke holes and inject toxins (cytotoxic) - - CELL MEDIATED IMMUNITY. They multiply rapidly, engulf, and digest antigen.
- Helper cells do what?
- Promote antibody production by B cells and stimulate T cells.
- Platelets (thrombocytes) are formed where from what?
- Red bone marrow from giant cells called megakaryocytes. Tiny fragments break up to form platelets.
- 4 major plasma proteins?
- albumin, globulins, fibrinogen, and prothrombin.
- Albumin does what? When does edema result?
- Maintains proper proportion of water in the blood. Edema results when too much fluid from blood leaks out into the tissues.
- Another word for blood clotting? Final result is what? What are platelets important for? Explain the process of clotting. What clotting factor are people with hemophilia missing?
- Coagulation; fibrin clot (takes less than 15 minutes) from the plasma protein fibrinogen. Platelets are important in beginning the process following injury. Platelets clump (aggregate) at injury site. Then in combo with protein tissue factor, it promotes the formation of a clot. Missing VIII. Others are missing IX.
- How is a clot formed? How do clots not form in the bloodstream? What is an example of this?
- Fibrin threads trap red blood cells, platelets, and plasma. Then the clot retracts into a tight ball, leaving behind serum (fluid). Normally clots don't form in blood vessels. Anticoagulants are in the bloodstream which prevents thrombi and emboli from forming. Ex = heparin.
- Anemia: What is it? What is the most common type? What is this caused by?
- Deficiency in erythrocytes or hemoglobin. Most common = iron-deficiency anemia. Caused by lack of iron, which is required for hemoglobin production.
- Aplastic anemia: What is it? Cause? Pancytopenia? Treatment?
- Failure of blood cell production due to aplasia (absence of development, formation) of bone marrow cells. Cause is unknown. Pancytopenia occurs as stem cells fail to produce leukocytes, platelets, and erythrocytes. Treatment = bone marrow transplants and drugs inhibiting the immune system.
- Hemolytic anemia: What is it? Example? What happens with this?
- Reduction in red cells due to excessive destruction. Ex = cngenital spherocytic anemia (aka hereditary spherocytosis). Erythrocytes are spheroidal. Makes them fragile and easily destroyed.
- Pernicious anemia: What is it? Caused by what? Treatment?
- Lack of mature erythrocytes caused by inability to absorb vitamin B12 into the body. (Pernicious = ruinous or hurtful). B12 can't be absorbed without an intrinsic factor. Individuals with this problem don't have this factor in their gastric juice, and the result is unsuccessful maturation of red blood cells with an excess of large, immature, and poorly functioning ones in bone marrow and large oral red cells in circulation. Treatment is administered B12 for life.
- Sickle cell anemia: What is it? Caused by what? Symptoms? Who usually gets it more often?
- Hereditary condition characterized by abnormal shape of erythrocytes and by hemolysis. Sickle cell shape is caused by abnormal type of hemoglobin in the red cell. Distorted cells can't pass through small blood vessels normally, leading to thrombosis and dead tissue. Symptoms = arthralgias, acute attacks of abdominal pain, ulcerations of extremities. Defect particularly common in African ancestry.
- Thalassemia: What is it? Usually seen in what people? Leads to what? Thalassa means what?
- An inherited defect in ability to produce hemoglobin, usually seen in people of Mediterranean background. Usually leads to hypochromatic anemia with diminished hemoglobin content in red cells. "Thalassa" means "sea".
- Hemochromatosis: What is it? What can occur (4 things)?
- Excess iron deposits throughout body. Hepatomegaly, skin pigmentation, diabetes, and cardiac failure can occur.
- Polycythemia vera: What is it? Treatment?
- General increase in red blood cells (erythremia). Blood consistency is thick because of greatly increased numbers of RBCs. Bone marrow is hyperplastic. Treatment = reduction of red cell volume to normal levels by phlebotomy (removal of blood from vein) and by suppressing blood cell production with drugs.
- Hemophilia: What is it? Treatment?
- Excessive bleeding caused by hereditary lack of one protein substance (either VIII or IX) necessary for blood clotting. Platelet count is normal, but deficiency in clotting factors results in prolonged coagulation time. Treatment = administering deficient factor.
- Purpura: What is it? What is autoimmune thrombocytopenic purpura? Treatment?
- Multiple pinpoint hemorrhages and accumulation of blood under skin. Produce red-purple discoloration of the skin. Can be caused by having too few platelets. Cause may be immunologic (body produces factor that harms its own platelets). Autoimmune thromobcytopenic purpura is condition where patient makes an antibody that destroys platelets. Bleeding time is prolonged. Spleenectomy and drug therapy are treatments.