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72 Cards in this Set
- Front
- Back
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What is blood composed of?
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Blood is composed of formed elements and plasma.
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What is a hematocrit?
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The hematocrit is a measure of one formed element, erythrocytes, as a percentage of total blood volume.
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Describe the physical characteristics of blood
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Blood is a viscous, slightly alkaline fluid.
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Approximately what volume of blood does a normal adult carry?
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Blood volume of a normal adult is about 5 liters.
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What percentage of body weight is represented by blood?
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About 8% of total body weight.
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What distribution functions are served by blood?
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Distribution functions include delivery of oxygen and nutrients to body tissues, removal of metabolic wastes, and transport of hormones.
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What regulation functions involve blood?
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Regulation functions are maintenance of body temperature, of constant blood pH, and of adequate fluid volume.
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What protection functions involve blood?
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Protective functions include hemostasis and prevention of infection.
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Describe the physical characteristics of plasma. What is it's composition?
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Plasma is a straw-colored, viscous fluid and is 90% water. The remaining 10% is solutes, such as nutrients, respiratory gases, salts, hormones, and proteins.
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What percentage of whole blood is plasma?
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Plasma makes up 55% of whole blood.
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What are a few common plasma proteins? Where are most made?
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Plasma proteins, most made by the liver, include albumin, globulins, and fibrinogen. Albumin is an important blood buffer and contributes to the osmotic pressure of blood.
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What are some formed elements?
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Formed elements are erythrocytes, leykocytes, and platelets.
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Where do the formed elements in blood come from?
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All formed elements arise from hemocytoblasts in red bone marrow.
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What percentage of whole blood is composed of formed elements?
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45% of whole blood.
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Describe the physical characteristics of erythrocytes.
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Erythrocytes (red blood cells) are small, biconcave cells containing large amounts of hemoglobin. The have no nucleus and few organelles
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What allows erythrocytes to deform?
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Spectrin allows the cells to change shape as they pass through tiny capillaries.
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What is the major function of erythrocytes?
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Oxygen transport is the major function of erythrocytes.
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Describe the oxygen transport functions of erythrocytes.
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In the lungs, oxygen binds to iron atoms in hemoglobin molecules, producing oxyhemoglobin. In body tissues, oxygen dissociates from iron, producing deoxyhemoglobin.
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Describe the maturation process of red blood cells.
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Red blood cells begin as hemocytoblasts, and, through erythropoiesis, proceed from the proerythroblast (committed cell) stage to the erythroblast (early and late), normoblast, and reticulocyte stages. During this process, hemoglobin accumulates and the organelles and nucleus are extruded. Differentiation of reticulocytes is completed in the bloodstream.
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What two hormones affect erythropoiesis?
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Erythropoietin and testosterone enhance erythropoiesis.
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What substances are essential for the production of hemoglobin?
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Iron, vitamin B12, and folic acid are essential for production of hemoglobin.
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What is the approximate life span of a red blood cell?
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Red blood cells have a life span of approximately 120 days.
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How are old red blood cells recycled?
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Old and damaged erythrocytes are removed from the circulation by macrophages of the liver and spleen. Released iron from hemoglobin is stored as ferritin or hemosiderin to be reused. The bnalance of the the heme group is degraded to bilirubin and secreted in bile. Amino acids of globin are metabolized or recycled.
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What are two examples of erythrocyte disorders?
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Erythrocyte disorders include anemias and polycythemia.
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What is another name for leukocytes?
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Leukocytes are white blood cells.
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White blood cells have two main categories, what are they? What attributes do they have in common?
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All are nucleated, and all have crucial roles in defending against disease. Two main categories exist: granulocytes and agranulocytes.
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What are three examples of granulocytes?
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Granulocytes include neutrophils, basophils, and eosinophils.
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Describe basophils, neutrophils, and eosinophils.
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Basophils contain histamine, which enhances migration of leukocytes to inflammatory sites and promotes vasodilation. Neutrophils are active phagocytes. Eosinophils attack parasitic worms and their numbers increase during alergic reactions.
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Agranulocytes are subdivided into two categories - what are they? What is their role?
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Agranulocytes have crucial roles in immunity. They include lymphocytes, the "immune cells", and monocytes which differentiate into macrophages.
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What directs leukopoiesis?
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Leukopoiesis is directed by colony-stimulating factors and interleukins released by supporting cells of the bone marrow and mature white blood cells.
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What are some examples of leukocyte disorders?
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Leukocyte disorders include leukemias and infections mononuclosis.
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What are platelets? What do they do?
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Platelets are fragments of large, multinucleate megakaryocytes formed in red marrow. When a blood vessel is damaged, platelets form a plug to prevent blood loss and play a central role in the clotting cascade.
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What is hemostasis? What are the three phases of hemostasis?
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Hemostasis is prevention of blood loss. The three major phases of hemostasis are vascular spasms, platelet plug formation, and blood coagulation.
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How is blood loss handled by the body, prior to coagulation?
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Spasms of smooth muscle in blood vessel walls and accumulation of platelets (platelet plug) at the site of vessel injury provide a temporary means of stopping or slowing blood loss until coagulation occurs.
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How is blood coagulation initiated?
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Coagulation of blood may be initiated by either the intrinsic or the extrinsic pathway. Platelet phospholipid (PF3) exposed by tissue injury allows the extrinsic pathway to bypass many steps of the intrinsic pathway. A series of activated procoagulants oversees the intermediate steps of each cascade. The pathways converge as prothrombin is converted to thormbin.
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In tissue repair, what happens after the clot is formed?
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After a clot is formed, clot retraction occurs. Serum is squeezed out and the ruptured vessel edges are drawn together. The vessel is repaired by smooth muscle, connective tissue, and endotelial cell proliferation and migration.
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What happens to clots after healing is complete? What is the technical term for this?
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When healing is complete, clot digestion occurs. (Fibrinolysis).
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How is abnormal expansion of clots prevented?
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Abnormal expansion of clots is prevented by removal of coagulation factors in contact with rapidly flowing blood and by inhibition of activated blood factors. Prostacyclin (PGI2) and nitric oxide secreted by the endothelial cells belp prevent undsesirable (unnecessary) clotting.
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What is a deficit of platelets called? What is the result?
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Thrombocytopenia, a deficit of platelets, causes spontaneous bleeding from small blood vessels.
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What causes hemophilia?
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Hemophilia is caused by a genetic deficiency of certain coagulation factors.
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What secondary effect can liver disease have, with respect to blood?
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Liver disease can also cause bleeding disorders because many coagulation proteins are formed by the liver.
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What procedure is called for with severe or rapid blood loss?
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Whole blood transfusions are given to replace severe and rapid blood loss. Packed RBCs are given to replace lost O2-carrying capacity.
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What factor is used to determine blood group in blood typing?
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Blood group is based on agglutinogens (antigens) present on red blood cell membranes.
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What happens when the wrong blood type is used in a transfusion?
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When mismatched blood is transfused, the recipient's agglutinins (plasma antibodies) clump the foreign RBCs; the clumped cells are then lysed. Blood vessels may be blocked by clumped RBCs. Released hemoglobin may precipitate in the kidney tubules, causing renal shutdown.
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What procedure must be performed before whole blood can be transfused?
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Before whole blood can be transfused, it must be typed and cross matched so that transfusion reactions are avoided. The most important blood groups for which blood must be types are the ABO and Rh groups.
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What is usually used to replace lost plasma?
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Plasma can be replaced with balanced electrolyte solutions, and these are generally preferred over plasma expanders.
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What is the utility of diagnostic blood tests?
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Diagnostic blood tests can provide large amounts of information about the current status of the blood and the body as a whole
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What are the hematopoietic sites during fetal development?
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Fetal hematopoietic sites include the yolk sac, liver, and spleen. By the seventh month of development, the red bone marrow is the primary blood-forming site.
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How do blood cells develop?
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Blood cells develop from blood islands derived from mesoderm. Fetal blood contains hemoglobin F. After birth, hemoglobin A is formed.
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What blood-related problems are associated with aging?
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The major blood-related problems associated with aging are leukemia, anemia, and thromoembolytic disease.
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Suppose a sample of normal adult whole blood was spun up in a centrifuge. What layers would you expect to see, in what percentages, starting with the heaviest elements at the bottom of the tube?
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The bottom layer, a reddish mass composing 45% of the sample, would be erythrocytes, or red blood cells. This measure is also known as the hematocrit. (normally 47% +/- 5% in males, 42% +/- 5% in females) The middle layer, thin and whitish, would be the buffy coat, composing less than 1% of the sample, and would consist of leukocytes and platelets. The final 55% at the top of the sample would be plasma.
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Two samples of blood are shown to you, one "bright scarlet" in color, the other "dark red" - which has a greater oxygen content?
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The "bright scarlet" sample has a higher oxygen content.
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Standard blood stats - what are the adult norms for blood pH, temperature, percentage of body weight, average volume, and viscosity as compared to water?
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Normal blood pH ranges between 7.35-7.45
Normal blood temperature is approximately 100.4 degrees farenheit, 38 degrees celsius Blood accounts for 8% of body weight Normal volume for healthy adult males is 5 to 6 liters (about 1.5 gallons), 4 to 5 liters in females. Compared to water, blood is approximately 5 times as viscous, largely due to formed elements. |
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How many molecules of oxygen can a hemoglobin molecule transport?
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4 O2 per hemoglobin molecule.
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What does the term "committed cell" refer to?
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A committed cell is a blood cell precursor whose path to specialization is determined. For example, the proerythroblast can only become an erythrocyte, not one of the leukocytes.
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What immediate danger is imposed by athletes practicing blood doping?
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By injecting EPO, healthy athletes increase their normal hematocrit from 45% to as much as 65%. Then, with the dehydration that occurs in a long race, the blood concentrates even further, becoming a thick, sticky sludge that can cause clotting, stroke, and even heart failure.
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How would you expect blood levels of bilirubin to change in a person that has severe liver disease?
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It would increase because the liver's processing functions are impaired.
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What percentage of the body's iron supply is stored in hemoglobin?
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Approximately 65% (about 4000 mg)
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What is the average amount of iron lost by men and women daily? What accounts for the disparity in amounts between the sexes?
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Approximately 1.7 mg in women and 0.9 mg in men. Menstrual flow accounts for the additional losses.
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What form of movement is used by leukocytes once they are out of the bloodstream?
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Amoeboid motion (they form flowing cytoplasmic extensions that move them along)
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White blood cells follow the chemical trail of molecules released by damaged cells or other leukocytes - what is the formal name for this behavior?
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Positive chemotaxis
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A specific blood type is described as a universal donor - another is described as a universal recipient - what are these two types?
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Type O is a universal donor, whereas Type AB is a universal recipient
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The blood volume in an adult averages approximately:
A) 1L B) 3L C) 5L D) 7L |
C) 5L
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The hormonal stimulus that prompts red blood cell formation is:
A) serotonin B) heparin C) erythropoietin D) thrombopoietin |
C) erythropoietin
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All of the following are true of RBCs except:
A) biconcave disc shape B) life span of approximately 120 days C) contain hemoglobin D) contain nuclei |
D) contain nuclei
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The most numerous WBC is the:
A) eosinophil B) neutrophil C) monocyte D) lymphocyte |
B) neutrophil
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Blood proteins play an important part in:
A) blood clotting B) immunity C) maintenance of blood volume D) all of the above |
D) all of the above
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The white blood cell that releases histamine and other inflammatory chemicals is the:
A) basophil B) neutrophil C) monocyte D) eosinophil |
A) basophil
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The blood cell that can become an antibody-secreting cell is the:
A) lymphocyte B) megakaryocyte C) neutrophil D) basophil |
A) lymphocyte
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Which of the following does not promote multiple steps in the clotting pathway?
A) PF3 B) factor XI C) thrombin D) Ca2+ |
B) factor XI
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The normal pH of the blood is about:
A) 8.4 B) 7.8 C) 7.4 D) 4.7 |
C) 7.4
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Suppose your blood was found to be AB positive. This means that:
A) agglutinogens A and B are present on your red blood cells B) theere are no anti-A or anti-B agglutinins in your plasma C) your blood is Rh+ D) all of the above |
D) all of the above
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