Chapter 11 Blood hem/o, hemat/o

Mosby items and derived items © 2008 by Mosby, Inc., an affiliate of Elsevier Inc. Blood  The main functions of Blood is transportation and protection  The two systems that help accomplish these functions are the Circulatory Lymphatic Systems. Slide 2

Mosby items and derived items © 2008 by Mosby, Inc., an affiliate of Elsevier Inc. BLOOD COMPOSITION (Table 11-1)  Blood plasma  Definition—blood minus its formed elements  Composition—water containing many dissolved substances (e.g., foods, salts, and hormones)  Amount of blood—varies with size and sex; 4 to 6 L about average; about 7% to 9% of body weight  Blood plasma also contains plasma proteins: albumins (thicken & maintain blood volume), globulins (containing antibodies to fight infection), fibrinogen (needed for blood clotting).  Serum is plasma minus the clotting factor, fibrinogen Slide 3

Mosby items and derived items © 2008 by Mosby, Inc., an affiliate of Elsevier Inc. BLOOD COMPOSITION  Formed elements of blood  Types RBCs (erythrocytes) RBCs (erythrocytes) WBCs (leukocytes) WBCs (leukocytes)  Granular leukocytes—neutrophils, eosinophils, and basophils  Nongranular leukocytes—B & T lymphocytes and monocytes Platelets, or thrombocytes Platelets, or thrombocytes  Count RBCs—4.5 to 5 million per mm 3 of blood RBCs—4.5 to 5 million per mm 3 of blood WBCs—5000 to 10,000 per mm 3 of blood WBCs—5000 to 10,000 per mm 3 of blood Platelets—300,000 per mm 3 of blood Platelets—300,000 per mm 3 of blood  Formation—red bone marrow (myeloid tissue) forms all blood cells except some lymphocytes and monocytes, which are formed by lymphatic tissue in the lymph nodes, thymus, and spleen Slide 4

Mosby items and derived items © 2008 by Mosby, Inc., an affiliate of Elsevier Inc. BLOOD COMPOSITION  RBCs  Structure—disk-shaped, without nuclei  Functions—transport oxygen and carbon dioxide  Anemia—inability of blood to carry adequate oxygen to tissues; caused, for example, by: Inadequate RBC numbers Inadequate RBC numbers Deficiency of hemoglobin Deficiency of hemoglobin Pernicious anemia—deficiency of vitamin B12 Pernicious anemia—deficiency of vitamin B12  Polycythemia—abnormally high RBC count  Hematocrit (Hct) test—medical test in which a centrifuge is used to separate whole blood into formed elements and liquid fraction (Figure 11-3) Buffy coat is WBC and platelet fraction Buffy coat is WBC and platelet fraction Normal RBC level is about 45% Normal RBC level is about 45% Erroneous test result can be caused by dehydration Erroneous test result can be caused by dehydration  In the adult hemapoeisis (the creation of RBCs) mainly occurs in the sternum, ribs, and hipbones. Small amounts are made vertebrae, clavicles, and cranial bones. Erythrocytes live for about 4 months. Slide 5

Mosby items and derived items © 2008 by Mosby, Inc., an affiliate of Elsevier Inc. BLOOD COMPOSITION  There are 3 main types of anemia in our textbook:  Hemorrhagic anemia, results from a decreased number of RBCs caused by hemorrhage resulting from accidents &/or internal bleeding.  Aplastic anemia, characterized by a reduction in RBCs resulting from the destruction of blood-forming bone marrow. Bone-marrow is chiefly destroyed by exposure to certain toxic chemicals, high-dose irradiation (x-rays), certain drugs, and chemotherapy agents.  Pernicious anemia, is a term used to describe the deficiency of RBCs resulting from a failure of the stomach lining to produce “intrinsic factor”—the substance that allows for Vit. B12 absorption (needed for the formation of RBCs).  Sickle cell anemia, a genetic disease that creates abnormal RBC hemoglobin with solid crystals formed on its surface causing the RBC to fold over on itself making it less soluble. A person can have a form of this disease called sickle cell trait caused inheriting only one defective gene from one parent. The gene can also be inherited from both parents, in which case the disease becomes more severe.  Iron deficiency anemia, is caused by an inadequate intake of iron in the diet. Iron is essential in the formation of hemoglobin. This is a global problem and is seen in the poor throughout the world. Slide 6

Mosby items and derived items © 2008 by Mosby, Inc., an affiliate of Elsevier Inc. Slide 7

Mosby items and derived items © 2008 by Mosby, Inc., an affiliate of Elsevier Inc. Slide 8 A centrifuge is used to spin down the blood. Remember that the RBCs are more dense and therefore will go to the bottom of the test tube. WBCs and platelets are less dense, therefore rest in the buffy coat. The remainder of the blood, plasma is the least dense and that is why it is on the top of the test tube. See figure 11-3.

Mosby items and derived items © 2008 by Mosby, Inc., an affiliate of Elsevier Inc. BLOOD COMPOSITION  WBCs (leukocytes)  General function—defense  WBC count Differential WBC count reveals proportions of each type of WBC Differential WBC count reveals proportions of each type of WBC Leukopenia—abnormally low WBC count ( less than 5,000) ex. AIDS Leukopenia—abnormally low WBC count ( less than 5,000) ex. AIDS Leukocytosis—abnormally high WBC count (usually bacterial infection) Leukocytosis—abnormally high WBC count (usually bacterial infection)  Neutrophils and monocytes carry out phagocytosis  Lymphocytes produce antibodies (B-lymphocytes) or directly attack foreign cells (T-lymphocytes)  Eosinophils protect against parasitic irritants that cause allergies  Basophils produce heparin, which inhibits clotting Slide 9

Mosby items and derived items © 2008 by Mosby, Inc., an affiliate of Elsevier Inc. BLOOD COMPOSITION  WBC disorders  Leukemia—cancer Elevated WBC count Elevated WBC count Cells do not function properly Cells do not function properly  Type identified by how quickly symptoms appear and cell type involved Acute lymphocytic leukemia (ALL) Acute lymphocytic leukemia (ALL) Acute myeloid leukemia (AML) Acute myeloid leukemia (AML) Chronic lymphocytic leukemia (CLL) Chronic lymphocytic leukemia (CLL) Chronic myeloid leukemia (CML) Chronic myeloid leukemia (CML) Slide 10

Mosby items and derived items © 2008 by Mosby, Inc., an affiliate of Elsevier Inc. BLOOD COMPOSITION  Platelets and blood clotting (Figure 11-6)  Platelets play an essential role in blood clotting  Blot clot formation Clotting factors released at the injury site produce prothrombin activator Clotting factors released at the injury site produce prothrombin activator Prothrombin activator and calcium convert prothrombin to thrombin Prothrombin activator and calcium convert prothrombin to thrombin Thrombin triggers formation of fibrin, which traps RBCs to form a clot Thrombin triggers formation of fibrin, which traps RBCs to form a clot Slide 11

Mosby items and derived items © 2008 by Mosby, Inc., an affiliate of Elsevier Inc. Slide 12

Mosby items and derived items © 2008 by Mosby, Inc., an affiliate of Elsevier Inc. Slide 13

Mosby items and derived items © 2008 by Mosby, Inc., an affiliate of Elsevier Inc. BLOOD TYPES  ABO system (Figure 11-7)  Antigen—substance that can activate immune system  Antibody—substance made by body in response to stimulation by an antigen  Blood types Type A blood—type A self-antigens in RBCs; anti-B type antibodies in plasma Type A blood—type A self-antigens in RBCs; anti-B type antibodies in plasma Type B blood—type B self-antigens in RBCs; anti-A type antibodies in plasma Type B blood—type B self-antigens in RBCs; anti-A type antibodies in plasma Type AB blood—type A and type B self-antigens in RBCs; no anti-A or anti-B antibodies in plasma Type AB blood—type A and type B self-antigens in RBCs; no anti-A or anti-B antibodies in plasma Type O blood—no type A or type B self-antigens in RBCs; both anti-A and anti-B antibodies in plasma Type O blood—no type A or type B self-antigens in RBCs; both anti-A and anti-B antibodies in plasma Slide 14

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Mosby items and derived items © 2008 by Mosby, Inc., an affiliate of Elsevier Inc. BLOOD TYPES  Rh system  Rh-positive blood—Rh factor antigen present in RBCs  Rh-negative blood—no Rh factor present in RBCs; no anti-Rh antibodies present naturally in plasma; anti-Rh antibodies, however, appear in the plasma of Rh-negative persons if Rh- positive RBCs have been introduced into their bodies Slide 16

Mosby items and derived items © 2008 by Mosby, Inc., an affiliate of Elsevier Inc. BLOOD TYPES  Universal donor and universal recipient blood  Type O  —universal donor blood  Type AB + —universal recipient blood  Erythroblastosis fetalis—may occur when Rh-negative mother carries a second Rh- positive fetus; caused by mother’s Rh antibodies reacting with baby’s Rh-positive cells Slide 17