1. Human Anatomy, 3rd edition Prentice Hall, © 2001 Blood Chapter 20

2. Human Anatomy, 3rd edition Prentice Hall, © 2001 Introduction –Functions Transport medium Regulation Protection –Composition Plasma – fluid Formed elements – cells & cell fragments –Volume varies Average = 5 liters

3. Human Anatomy, 3rd edition Prentice Hall, © 2001 Plasma –= about 55% of the blood –Composition Mostly water Plasma proteins Dissolved foods, wastes, gases, ions –Differences between plasma and intersititial fluid Plasma has more dissolved gases Plasma has more proteins Concentrations of small molecules are similar

4. Human Anatomy, 3rd edition Prentice Hall, © 2001 Plasma Proteins –Most are made by the liver Albumins – transport fatty acids & steroids Globulins – immune functions Fibrinogen – blood clotting

5. Human Anatomy, 3rd edition Prentice Hall, © 2001 Composition of Blood

6. Human Anatomy, 3rd edition Prentice Hall, © 2001 Formed Elements –Blood cells and cell fragments –Produced by hemopoiesis Arise from stem cells called hemocytoblasts –Types of formed elements Erythrocytes – red blood cells (RBCs) Leukocytes – white blood cells (WBCs) Thrombocytes – platelets

7. Human Anatomy, 3rd edition Prentice Hall, © 2001 Erythrocytes –Biconcave, have no nuclei (or other organelles) Lifespan = about 120 days –Production occurs in the red bone marrow Erythropoiesis Controlled by the hormone erythropoietin –Functions Transport O 2 & some CO 2 –Bound to hemoglobin –Anemia –Polycythemia (erythrocytosis)

8. Human Anatomy, 3rd edition Prentice Hall, © 2001 A Red Blood Cell

9. Human Anatomy, 3rd edition Prentice Hall, © 2001 SEM of RBCs

10. Human Anatomy, 3rd edition Prentice Hall, © 2001 Hemoglobin

11. Human Anatomy, 3rd edition Prentice Hall, © 2001 Numbers of RBCs –Normally 4.3-5.8 million cells/mm 3 of blood Males = 5.1-5.8 million/mm 3 Females = 4.3-5.2 million/mm 3 –Numbers affect viscosity of blood –The percentage of erythrocytes, by volume, in whole blood is the hematocrit Males = 45% Females = 42%

12. Human Anatomy, 3rd edition Prentice Hall, © 2001 Leukocytes –About 5000 – 10,000/mm 3 of blood –Produced by leukopoiesis in red bone marrow –Location – mostly in peripheral tissues –Functions Defense against pathogens Removal of toxins, wastes, abnormal or damaged cells –As large or larger than RBCs, contain nuclei

13. Human Anatomy, 3rd edition Prentice Hall, © 2001 Types of WBCs –Granulocytes have granules in their cytoplasm Neutrophils are phagocytic towards bacteria –55-65% of circulating WBCs Eosinophils are involved in allergic reactions and parasitic infections –2-4% of circulating WBCs Basophils exaggerate inflammation at the site of an injury –Less than 1% of circulating WBCs

14. Human Anatomy, 3rd edition Prentice Hall, © 2001 A Neutrophil

15. Human Anatomy, 3rd edition Prentice Hall, © 2001 An Eosinophil

16. Human Anatomy, 3rd edition Prentice Hall, © 2001 A Basophil

17. Human Anatomy, 3rd edition Prentice Hall, © 2001 Types of WBCs –Agranulocytes do not have granules in their cytoplasm Monocytes are phagocytes and form the macrophages of the tissues –2-8% of the WBC population Lymphocytes are responsible for specific immunity –B lymphocytes produce antibodies –T lymphocytes attack foreign cells directly –20-30% of the WBC population

18. Human Anatomy, 3rd edition Prentice Hall, © 2001 A Monocyte

19. Human Anatomy, 3rd edition Prentice Hall, © 2001 A Lymphocyte

20. Human Anatomy, 3rd edition Prentice Hall, © 2001 Thrombocytes –Formed from fragments of large cells called megakaryocytes –Have no nuclei, lifespan is 10 – 12 days –Number about 350,000/mm 3 of blood –Function Involved in the clotting mechanism

21. Human Anatomy, 3rd edition Prentice Hall, © 2001 Platelet Formation

22. Human Anatomy, 3rd edition Prentice Hall, © 2001 Origins & Differentiation of Blood Cells

23. Human Anatomy, 3rd edition Prentice Hall, © 2001 Blood Types –Antigens are specific proteins on RBC membranes Blood is classified based on these antigens A, B, O Rh –Antigens are accompanied by other proteins in plasma – antibodies –Specific antibodies bind with their antigens, causing agglutination

24. Human Anatomy, 3rd edition Prentice Hall, © 2001 Blood Types