17 8 th Ed

1. 178th Ed Blood

2. Blood Composition 2 • Blood: a fluid connective tissue composed of • Plasma • Formed elements • Erythrocytes (red blood cells, or RBCs) • Leukocytes (white blood cells, or WBCs) • Platelets

3. Blood Composition 3 • Hematocrit • Percent of blood volume that is RBCs • 47% ± 5% for males • 42% ± 5% for females

4. 4 Figure 17.1 pg. Page 635 Formed elements Plasma • 55% of whole blood • Least dense component Buffy coat • Leukocytes and platelets • <1% of whole blood Erythrocytes 2 • 45% of whole blood • Most dense component 1 Centrifuge the blood sample. Withdraw blood and place in tube. Figure 16.1

5. Physical Characteristics and Volume 5 • Color scarlet to dark red • pH 7.35–7.45 • 38C • ~8% of body weight • Average volume: 5–6 L for males, and 4–5 L for females

6. Functions of Blood 6 • Distribution of • O2 and nutrients to body cells • Metabolic wastes to the lungs and kidneys for elimination • Hormones from endocrine organs to target organs

7. Functions of Blood 7 • Regulation of • Body temperature by absorbing and distributing heat • Normal pH using buffers

8. Functions of Blood 8 • Protection against • Blood loss • Plasma proteins, fibrinogen and platelets initiate clot formation • Infection • Antibodies • Complement proteins • WBCs defend against foreign invaders

9. Blood Plasma 9 • 90% water • Proteins are mostly produced by the liver • 60% albumin • 36% globulins • 4% fibrinogen

10. Blood Plasma 10 • Nitrogenous by-products of metabolism—lactic acid, urea, creatinine • Nutrients—glucose, carbohydrates, amino acids • Electrolytes—Na+, K+, Ca2+, Cl–, HCO3– • Respiratory gases—O2 and CO2 • Hormones

11. Formed Elements 11 • Only WBCs are complete cells • RBCs have no nuclei or organelles • Platelets are cell fragments • Most formed elements survive in the bloodstream for only a few days • Most blood cells originate in bone marrow and do not divide

12. 12 Fig.17.2 Pg. 637 Erythrocytes Platelets Monocyte Neutrophils Lymphocyte Figure 16.2

13. Erythrocytes 13 • Biconcave discs, anucleate, essentially no organelles • Filled with hemoglobin (Hb) for gas transport • Contain the plasma membrane proteins • Provide flexibility to change shape as necessary • Are the major factor contributing to blood viscosity

14. fig. 17.3 • Pg. 637 2.5 µm Side view (cut) 7.5 µm Top view Figure 16.3

15. Erythrocytes 15 • Structural characteristics contribute to gas transport • Biconcave shape—huge surface area relative to volume • >97% hemoglobin (not counting water) • No mitochondria; ATP production is anaerobic; no O2 is used in generation of ATP • 4.3 million -5.8 million / cubic mm

16. Erythrocyte Function 16 • RBCs are dedicated to respiratory gas transport • Hemoglobin binds reversibly with oxygen

17. Erythrocyte Function 17 • Hemoglobin structure • Protein globin: two alpha and two beta chains • Heme pigment (molecule) bonded to each globin chain (4) • Iron atom in each heme can bind to one O2 molecule • So, each Hb molecule can transport four O2

18. 18 Fig. 17.4; pg. 638 bGlobin chains Heme group a Globin chains (a) Hemoglobin consists of globin (two alpha and two beta polypeptide chains) and four heme groups. (b) Iron-containing heme pigment. Figure 16.4

19. Hemoglobin (Hb) 19 • O2 loading in the lungs • Produces oxyhemoglobin (ruby red) • O2 unloading in the tissues • Produces deoxyhemoglobin or reduced hemoglobin (dark red) • CO2 loading in the tissues • Produces carbaminohemoglobin (carries 20% of CO2 in the blood) (carbonmonoxide)

20. Hematopoiesis 20 • Hematopoiesis (hemopoiesis): blood cell formation • Occurs in red bone marrow of axial skeleton, girdles and proximal epiphyses of humerus and femur

21. Hematopoiesis 21 • Hemocytoblasts (hematopoietic stem cells) • Give rise to all formed elements • Hormones push the cell toward a specific pathway of blood cell development

22. 22 Figure 17.5 pg. 639

23. Stem cell Committed cell Developmental pathway Phase 1 Ribosome synthesis Phase 2 Hemoglobin accumulation Phase 3 Ejection of nucleus Reticulo- cyte Erythro- cyte Proerythro- blast Early erythroblast Late erythroblast Normoblast Hemocytoblast Figure 16.5

24. Fate and Destruction of Erythrocytes 24 • Life span: 100–120 days • Old RBCs become fragile, and Hb begins to degenerate • Macrophages engulf dying RBCs in the spleen

25. Erythrocyte Disorders 25 • Anemia: blood has abnormally low O2-carrying capacity • A sign rather than a disease itself • Blood O2 levels cannot support normal metabolism • Accompanied by fatigue, paleness, shortness of breath, and chills

26. Causes of Anemia 26 • Low hemoglobin content • Iron-deficiency anemia • Secondary result of hemorrhagic anemia or • Inadequate intake of iron-containing foods • Impaired iron absorption – folic acid • Hemorrhaging: Ulcers • Black stool vs. frank blood

27. Causes of Anemia 27 • Sickle-cell anemia • Defective gene codes for abnormal hemoglobin (HbS) • Causes RBCs to become sickle shaped in low-oxygen situations

28. 28 Fig. 17.8 pg. 642 (a) Normal erythrocyte has normal hemoglobin amino acid sequence in the beta chain. 1 2 3 4 5 6 7 146 (b) Sickled erythrocyte results from a single amino acid change in the beta chain of hemoglobin. 1 2 3 4 5 6 7 146 Figure 16.8

29. Leukocytes 29 • Make up <1% of total blood volume • Can leave capillaries via diapedesis • Move through tissue spaces by ameboid motion and positive chemotaxis • Leukocytosis: WBC count over 11,000/mm3 • Normal response to bacterial or viral invasion

30. Fig. 17.9 pg.644 Differential WBC count (All total 4800– 10,800/l) Formed elements Platelets Granulocytes Neutrophils (50–70%) Leukocytes Eosinophils (2–4%) Basophils (0.5–1%) Erythrocytes Agranulocytes Lymphocytes (25 – 45%) Monocytes (3 – 8%) Figure 16.9

31. Granulocytes 31 • Granulocytes: neutrophils, eosinophils, and basophils • Cytoplasmic granules stain specifically with Wright’s stain • Larger and shorter-lived than RBCs • Lobed nuclei • Phagocytic

32. Neutrophils 32 • Most numerous WBCs • Polymorphonuclear leukocytes (PMNs) • Fine granules take up both acidic and basic dyes • Give the cytoplasm a lilac color • Granules contain hydrolytic enzymes or defensins • Very phagocytic—“bacteria slayers”

33. Eosinophils 33 • Red-staining, bilobed nuclei • Red to crimson (acidophilic) coarse, lysosome-like granules • Digest parasitic worms that are too large to be phagocytized • Modulators of the immune response

34. Basophils 34 • Rarest WBCs • Large, purplish-black (basophilic) granules contain histamine • Histamine: an inflammatory chemical that acts as a vasodilator and attracts other WBCs to inflamed sites • Are functionally similar to mast cells (histamines & heparin)

35. 35 Fig. 17.10 a b c pg. 644 (a) Neutrophil; multilobed nucleus (b) Eosinophil; bilobed nucleus, red cytoplasmic granules (c) Basophil; bilobed nucleus, purplish-black cytoplasmic granules Figure 16.10 (a-c)

36. Agranulocytes 36 • Agranulocytes: lymphocytes and monocytes • Lack visible cytoplasmic granules • Have spherical or kidney-shaped nuclei

37. Lymphocytes 37 • Large, dark-purple, circular nuclei with a thin rim of blue cytoplasm • Mostly in lymphoid tissue; few circulate in the blood • Crucial to immunity

38. Lymphocytes 38 • Two types • T Cells: Regulatory T’s: identify antigens Killer T’s: Kill identified cells • B cells produce humeral immunity – protein antibodies circulating in the blood

39. Monocytes 39 • The largest leukocytes • Abundant pale-blue cytoplasm • Dark purple-staining, U- or kidney-shaped nuclei

40. 40 Monocytes PHYSIOLOGY - SKIP • Leave circulation, enter tissues, and differentiate into macrophages • Actively phagocytic cells; crucial against viruses, intracellular bacterial parasites, and chronic infections • Activate lymphocytes to mount an immune response

41. 41 Never let monkeys eat bananas Neutrophils-Lymphocytes-Monocytes-Eosinophils-Basophils Let monkeys are agranulocytes

42. 42 fig. 17.10 a & b

43. 43. Fig 17.10 c page 644

44. 44 fig. 17.10; pg. 644 (d) Small lymphocyte; large spherical nucleus (e) Monocyte; kidney-shaped nucleus Figure 16.10d, e

45. 45 Table 17.2; pg. 645 Table 16.2 (1 of 2)

46. 46 Table 17.2; pg. 645 Table 16.2 (2 of 2)

47. Leukopoiesis 47 • Production of WBCs • Stimulated by chemical messengers from bone marrow and mature WBCs • All leukocytes originate from hemocytoblasts

48. 48 Table 17.11; page 645 Stem cells Hemocytoblast Lymphoid stem cell Myeloid stem cell Committed cells Myeloblast Myeloblast Myeloblast Monoblast Lymphoblast Developmental pathway Promonocyte Promyelocyte Promyelocyte Promyelocyte Prolymphocyte Eosinophilic myelocyte Basophilic myelocyte Neutrophilic myelocyte Basophilic band cells Eosinophilic band cells Neutrophilic band cells Monocytes Neutrophils Eosinophils Basophils Lymphocytes (a) (e) (b) (c) (d) Agranular leukocytes Some become Granular leukocytes Some become Figure 16.11

49. Leukocyte Disorders 49 • Leukopenia • Abnormally low WBC count—drug induced • Leukemias • Cancerous conditions involving WBCs • Named according to the abnormal WBC clone involved • Myelocytic leukemia involves myeloblasts • Lymphocytic leukemia involves lymphocytes • Acute leukemia involves blast-type cells and primarily affects children • Chronic leukemia is more prevalent in older people

50. Platelets 50 • Small fragments of megakaryocytes • Formation is regulated by thrombopoietin • Blue-staining outer region, purple granules • Granules contain serotonin, Ca2+, enzymes, ADP, and platelet-derived growth factor (PDGF)