1. © 2014 Pearson Education, Inc. Blood

2. © 2014 Pearson Education, Inc. Blood Circulation Circulatory system is divided into Cardiovascular system Lymphatic system Blood Transport mechanism for Nutrients Signaling molecules Respiratory gases Waste products

3. © 2014 Pearson Education, Inc. Blood Circulation Powered by the pumping action of the heart Oxygen and nutrients diffuse across capillary walls to body tissues Regulates body temperature Composition of Blood Blood has cellular and liquid components Is a specialized connective tissue Blood cells—formed elements Plasma—liquid portion of blood

4. © 2014 Pearson Education, Inc. Composition of Blood Hematocrit Is the measure of % RBC Males: 47% ± 5% Females: 42% ± 5% Buffy coat Is portion of blood composed of leukocytes and platelets Present at junction of plasma and RBCs

5. © 2014 Pearson Education, Inc. Figure 18.1 Major components of whole blood. Withdraw blood and place in tube. Centrifuge the blood sample. 55% of whole blood Least dense component Leukocytes and platelets  1% of whole blood 45% of whole blood Most dense component Plasma Buffy coat Erythrocytes Formed elements 21

6. © 2014 Pearson Education, Inc. Blood Plasma Clear, sticky fluid portion of blood Approximately 90% water Contains over 100 kinds of molecules Ions—Na + and Cl – Nutrients Sugars, amino acids, lipids Wastes Carbon dioxide, urea, ammonia Proteins

7. © 2014 Pearson Education, Inc. Blood Plasma Three main proteins Albumin Prevents water from diffusing out of blood vessels Globulins Include antibodies and blood proteins that transport lipids, iron, and copper Fibrinogen One of the molecules involved in chemical reactions for blood clotting

8. © 2014 Pearson Education, Inc. Figure 18.2b Blood cells. Erythrocytes Platelets Monocyte Lymphocyte Neutrophil Eosinophil Photomicrograph of a human blood smear, Wright’s stain (610  )

9. © 2014 Pearson Education, Inc. Erythrocytes Most numerous of the formed elements Have no organelles or nuclei Are packed with oxygen-carrying hemoglobin Hemoglobin molecule bears four oxygen molecules Each O 2 bears an Fe Iron atoms give blood it’s red color

10. © 2014 Pearson Education, Inc. Figure 18.3 Structure of erythrocytes. Side view (cut) Top view 2.5  m 7.5  m

11. © 2014 Pearson Education, Inc. Leukocytes—White Blood Cells (WBCs) Protect the body from infectious microorganisms Function outside the bloodstream in loose connective tissue Originate in bone marrow

12. © 2014 Pearson Education, Inc. Neutrophils (50–70%) Eosinophils (2–4%) Basophils (0.5–1%) Lymphocytes (25–45%) Monocytes (3–8%) Platelets Leukocytes Erythrocytes Formed elements (not drawn to scale) Differential WBC count (All total 4800– 10,800 cells/  l) Mnemonic: “Never Let Monkeys Eat Bananas”

13. © 2014 Pearson Education, Inc. Granulocytes Neutrophils Most numerous WBC First line of defense in inflammatory response Phagocytize and destroy bacteria Granulocytes Neutrophil: Multilobed nucleus, pale red and blue cytoplasmic granules

14. © 2014 Pearson Education, Inc. Granulocytes Eosinophils 1–4% of all WBCs Play a role in ending allergic reactions by phagocytizing allergens Secrete enzymes that degrade histamines Granulocytes Eosinophil: Bilobed nucleus, red cytoplasmic granules

15. © 2014 Pearson Education, Inc. Granulocytes Basophils-0.5% of all leukocytes Function in inflammation mediation Direct later stages of inflammation in allergies and parasitic infections Granulocytes Basophil: Bilobed nucleus, purplish-black cytoplasmic granules

16. © 2014 Pearson Education, Inc. Agranulocytes Lymphocytes—~35% of WBCs The most important cells of the immune system Fighting infectious organisms Act against a specific foreign molecule (antigen) 2 types of lymphocytes T cells—attack foreign cells directly B cells—multiply to become plasma cells Agranulocytes Lymphocyte (small): Large spherical nucleus, thin rim of pale blue cytoplasm

17. © 2014 Pearson Education, Inc. Agranulocytes Monocytes—compose 4–8% of WBCs The largest leukocytes Transform into macrophages Phagocytic cells Agranulocytes Monocyte: Kidney-shaped nucleus, abundant pale blue cytoplasm

18. © 2014 Pearson Education, Inc. Platelets Cell fragments Break off from megakaryocytes Function in clotting of blood

19. © 2014 Pearson Education, Inc. Table 18.1 Summary of Formed Elements of the Blood (1 of 2)

20. © 2014 Pearson Education, Inc. Table 18.1 Summary of Formed Elements of the Blood (2 of 2)

21. © 2014 Pearson Education, Inc. Blood Cell Formation Hematopoiesis—process by which blood cells are formed in red marrow 100 billion new blood cells formed each day

22. © 2014 Pearson Education, Inc. Bone Marrow as the Site of Hematopoiesis Bone marrow—located within all bones Red marrow—actively generates new blood cells Contains immature erythrocytes In adults, in red marrow Yellow marrow—dormant Contains many fat cells Located in the long bones of adults

23. © 2014 Pearson Education, Inc.

24. Cell Lines in Blood Cell Formation All blood cells originate in bone marrow All originate from one cell type Hemopoietic blood stem cell (pluripotential hematopoeitic stem cell) Lymphoid stem cells Give rise to lymphocytes Myeloid stem cells Give rise to all other blood cells

25. © 2014 Pearson Education, Inc. Disorders of the Blood Disorders of erythrocytes Polycythemia Abnormal excess of erythrocytes Anemia Erythrocyte levels or hemoglobin concentrations are low

26. © 2014 Pearson Education, Inc. Disorders of the Blood Disorders of erythrocytes (continued) Sickle cell disease Inherited condition Results from a defective hemoglobin molecule Erythrocytes distort into a sickle shape

27. © 2014 Pearson Education, Inc. Disorders of the Blood Disorders of leukocytes Leukemia—a form of cancer Classified as lymphoblastic or myeloblastic Disorders of platelets Thrombocytopenia Abnormally low concentration of platelets