1. Blood Cells in the body are fixed within tissues and must have nutrients and oxygen brought to them and waste removed. The blood is classified as a fluid matrix connective tissue –The cells and cell fragments are the formed elements and the matrix of the blood is fluid (plasma). –Formed elements make up about 45% and plasma 55% of the total blood volume. –Blood volume: 4-5 L in females, 5-6 L in males.

2. Blood Functions Distribution and transportation –Respiration –Nutritive –Excretory –Negative Aspects Regulation and Maintenance –Hormonal regulation –Thermoregulation –pH / acid-base balance –Fluid volume Protection –Clotting –Immunity

3. Major Components of the Circulatory System Two divisions: Cardiovascular and lymphatic systems. –Cardiovascular: Heart, blood vessels Heart Vessels –Lymphatic: lymphatic vessels and lymphoid tissues in spleen, thymus, tonsils, and lymph nodes. The fluid portion of the blood (plasma) passes through the capillary walls under hydrostatic pressure (interstitial fluid). Some interstitial fluid returns to the blood and some enters the lymphatic system –Lymphatic vessels carry interstitial fluid now called lymph back to the venous blood. –Lymph nodes along the way filter and cleanse the blood before it is returned.

7. Erythrocytes Structure –Biconcave, anucleate –4.8 million/mm3 in women. –5.4 million/mm3 in men. –7.5 um in diameter Components –Hemoglobin –Lipids, ATP, carbonic anhydrase Function –Transport oxygen from lungs to tissues and carbon dioxide from tissues to lungs

8. Hemoglobin Consists of: –4 globin molecules: 2 alpha and 2 beta chains 280 million per RBC. Transport carbon dioxide (carbonic anhydrase involved), nitric oxide. –4 heme molecules: Transport oxygen Iron is required for oxygen transport

11. Erythropoiesis Production of red blood cells –Stem cells proerythroblasts early erythroblasts intermediate late reticulocytes Erythropoietin: Hormone to stimulate RBC production

15. Hemolytic Anemia

16. Anemias Result of either a decrease in hemoglobin / RBC or in the number of RBCs. Symptoms: pale, lethargic, shortness of breath, tired. Aplastic anemia: inability of red bone marrow to produce RBCs caused by: damage to Red bone marrow, Iron of Folate deficiency Pernicious anemia - Vitman B12 deficiency Hemorhagic anemia - results from loss of blood Hemolytic anemia - erythrocytes rupture or are destroyed at an increased rate. Thalasemia - defective hemoglobin production

17. Malaria Sickle cell anemia

18. Formed Elements Red blood cells (erythrocytes) White blood cells (leukocytes) –Granulocytes Neutrophils Eosinophils Basophils –Agranulocytes Lymphocytes Monocytes Platelets (thrombocytes)

19. Production of Formed Elements Hematopoiesis or hemopoiesis: Process of blood cell production Stem cells: All formed elements derived from single population –Proerythroblasts: Develop into red blood cells –Myeloblasts: Develop into basophils, neutrophils, eosinophils –Lymphoblasts: Develop into lymphocytes –Monoblasts: Develop into monocytes –Megakaryoblasts: Develop into platelets

20. Hematopoiesis

23. Neutrophil Appearance –2-5 lobes –10-12 um –54-62% of white cells Characteristics –Fights bacterial and fungal infections –Contains peroxidases and defensins –Numbers increase with meningitis and appendicitis

24. Eosinophil Appearance –Bilobed nucleus –Red granules –11-14 um –1-3% of white blood cells Characteristics –Fights parasitic infections. –Releases anti- inflammatory chemicals. –Secretes enzymes that break down clots.

25. Basophils Appearance –Two indistinct lobes –Blue-purple granules –10-12 um –Less than 1% of WBC Characteristics –Release histamine –Chemoattractant for other WBCs –Releases heparin to prevent clots. BasophilEosinophil

27. Monocyte Apearance –Nucleus round, kidney or horseshoe shaped –12-20 um –3-9 % of WBC Characteristics –Transforms into macrophages

28. Lymphocyte Appearance –Round nucleus –6-14 um –25-33% of WBC Characteristics –Found in lymphoid tissue –Provides specific immune response T - lymphocytes B - lymphocytes

29. Leukocytes

30. Hemostasis Arrest of bleeding Events preventing excessive blood loss –Vascular spasm: Vasoconstriction of damaged blood vessels –Platelet plug formation –Coagulation or blood clotting

31. Thrombocytes Cell fragments pinched off from megakaryocytes in red bone marrow Important in preventing blood loss –Platelet plugs –Promoting formation and contraction of clots

33. Platelet Plug Formation

34. Coagulation Stages –Activation of prothrombinase –Conversion of prothrombin to thrombin –Conversion of fibrinogen to fibrin Pathways –Extrinsic –Intrinsic

35. Clot Formation

37. Fibrinolysis Clot dissolved by activity of plasmin, an enzyme which hydrolyzes fibrin

38. Blood Grouping Determined by antigens (agglutinogens) on surface of RBCs Antibodies (agglutinins) can bind to RBC antigens, resulting in agglutination (clumping) or hemolysis (rupture) of RBCs Groups –ABO and Rh

39. ABO Blood Groups

40. Agglutination Reaction

41. Rh Blood Group First studied in rhesus monkeys Types –Rh positive: Have these antigens present on surface of RBCs –Rh negative: Do not have these antigens present Hemolytic disease of the newborn (HDN) –Mother produces anti-Rh antibodies that cross placenta and cause agglutination and hemolysis of fetal RBCs

42. Erythroblastosis Fetalis

43. Diagnostic Blood Tests Type and crossmatch Complete blood count –Red blood count –Hemoglobin measurement –Hematocrit measurement White blood count Differential white blood count Clotting

44. Blood Disorders Erythrocytosis: RBC overabundance Anemia: Deficiency of hemoglobin –Iron-deficiency –Pernicious –Hemorrhagic –Hemolytic –Sickle-cell Hemophilia Thrombocytopenia Leukemia Septicemia Malaria Infectious mononucleosis Hepatitis