PowerLecture: Chapter 8

1. PowerLecture:Chapter 8 Blood

2. Learning Objectives • Describe the composition and functions of blood. • Explain how red blood cells transport oxygen. • Explain the basis of blood typing. • Define hemostasis and distinguish it from homeostasis.

3. Learning Objectives (cont’d) • Describe how blood disorders disrupt homeostasis and critical body functions, such as clotting.

4. Impacts/Issues Chemical Questions

5. Chemical Questions • Healthy people have contaminants in their blood. • The chemicals are products from everyday life: metals, secondhand cigarette smoke, pesticides, etc. • Most of the chemicals did not even exist 50 years ago. • Not enough is known about the long-term effects of these chemicals on human health, especially for the very young.

6. Useful References for Impacts/Issues The latest references for topics covered in this section can be found at the book companion website. Log in to the book’s e-resources page at www.thomsonedu.com to access InfoTrac articles. • Environmental Scorecard - In Your Community • InfoTrac: Elevated Blood Lead Levels in Refugee Children – New Hampshire, 2003–2004. Morbidity and Mortality Weekly Report, Jan. 21, 2005.

7. How Would You Vote? To conduct an instant in-class survey using a classroom response system, access “JoinIn Clicker Content” from the PowerLecture main menu. • Government regulation of substances such as lead seems to be effective. Should other suspect industrial chemicals be regulated? • a. Yes, until companies are forced to prove their chemicals are harmless before selling them, they should be regulated. • No, regulation hampers industry and is not necessary unless these chemicals are proven harmful.

8. Useful References for How Would You Vote? The latest references for topics covered in this section can be found at the book companion website. Log in to the book’s e-resources page at www.thomsonedu.com to access InfoTrac articles. • CDC: National Report on Human Exposure to Environmental Chemicals • Environmental Working Group: Body Burden • NRDC: Healthy Milk, Healthy Baby – Chemical Pollution and Mother’s Milk

9. Section 1 Blood: Plasma, Blood Cells, and Platelets

10. Blood: Plasma, Blood Cells, and Platelets • Blood is a connective tissue; it contains plasma, blood cells, and cell fragments called platelets. • Adult women of average size have 4-5 liters of blood in their bodies; men have slightly more. Figure 8.1

11. red blood cell white blood cell platelets Fig. 8.1, p.143

12. Blood: Plasma, Blood Cells, and Platelets • Plasma is the fluid part of blood. • Roughly 55% of whole blood is plasma, which is mostly water. • Plasma proteins perform a variety of tasks: • Albumin is important in maintaining osmotic balance and transports chemicals such as therapeutic drugs. • Other plasma proteins include protein hormones, as well as proteins involved in immunity, blood clotting, and the transport of lipids and vitamins. • Plasma further contains ions, glucose, amino acids, signaling molecules, and dissolved gases.

13. Blood: Plasma, Blood Cells, and Platelets • Red blood cells carry oxygen and CO2. • Erythrocytes, or red blood cells, (45% of whole blood) are biconcave disks. • They contain hemoglobin, an iron-containing protein that binds with oxygen. • They also carry a small amount of carbon dioxide. • Red blood cells originate from stem cellsin the bone marrow.

14. natural killer cells T lymphocytes neutrophils mast cells eosinophils basophils B lymphocytes forerunners of white blood cells (leukocytes) ? stem cells in marrow monocytes (immature phagocytes) red blood cells (erythrocytes) dendritic cells macrophages megakaryocytes platelets Fig. 8.2, p.145

15. Blood: Plasma, Blood Cells, and Platelets • White blood cells perform defense and cleanup duties. • Leukocytes, or white blood cells, make up a minor portion of whole blood and are responsible for housekeeping and defense; they also are derived from bone marrow. • Leukocytes are of two main types: • Granulocytes have stainable granules in the cytoplasm; they include neutrophils, eosinophils, and basophils; and they work in body defense activities. • Agranulocytes have no visible granules; monocytes become macrophages; and lymphocytes become B cells, T cells, and natural killer cells.

16. Blood: Plasma, Blood Cells, and Platelets • Platelets help clot blood. • Platelets are fragments of megakaryocytes produced by bone marrow stem cells. • They are short lived, numerous, and function in blood clotting.

17. Components Relative Amounts Functions Plasma portion (50%-60% of total volume): 91%-92% of plasma volume 7%-8% 1%-2% Solvent Defense, clotting, lipid transport, roles in extracellular fluid volume, etc. Roles in extracellular fluid volume, pH, etc. Water Plasma proteins (albumin, globulins, fibrinogen, etc.) Ions, sugars, lipids, amino acids, hormones, vitamins, dissolved gasses Plasma portion (50%-60% of total volume): White blood cells: Neutrophils Lymphocytes Monocytes(macrophages) Eosinophils Basophils Platelets Red blood cells 3,000-6,750 1,000-2,700 150-720 100-360 25-90 250,00-300,000 4,800,000-5,400,000 per microliter Phagocytosis during inflammation Immune responses Phagocytosis in all defense responses Defense against parasitic worms Secrete substances for inflammatory response and for fat removal from blood Roles in clotting Oxygen, carbon dioxide transport Fig. 8.1, p.143

18. Video: Immortality Industry • This video clip is available in CNN Today Videos for Anatomy and Physiology, 2004, Volume VIII. Instructors, contact your local sales representative to order this volume, while supplies last.

19. Useful References for Section 1 The latest references for topics covered in this section can be found at the book companion website. Log in to the book’s e-resources page at www.thomsonedu.com to access InfoTrac articles. • InfoTrac: FDA to Hear Artificial Blood Test Proposal. UPI NewsTrack, July 6, 2006.

20. Section 2 How Blood Transports Oxygen

21. How Blood Transports Oxygen • Hemoglobin is the oxygen carrier. • Only a tiny amount of oxygen is dissolved in blood plasma. • Most of the oxygen is bound to the heme groups of hemoglobin; oxygen-bearing hemoglobin is called oxyhemoglobin. • What determines how much oxygen hemoglobin can carry?

22. How Blood Transports Oxygen • The amount of oxygen bound to hemoglobin changes as conditions in the tissues vary. • Binding of oxygen is favored by conditions in the lungs: abundant oxygen, cooler temperature, and neutral pH. • Release of oxygen is favored in the tissues where the oxygen levels are lower, temperatures higher, and pH more acidic. • Hemoglobin also transports a small amount of carbon dioxide.

23. LUNGS TISSUES more O2 cooler less acidic less O2 warmer more acidic HbO2 HbO2 Hb + O2 Hb + O2 p.146

24. Animation: Globin and Hemoglobin Structure CLICKTO PLAY

25. How Blood Transports Oxygen • Each hemoglobin molecule has four polypeptide chains (globin proteins), each of which possesses a heme group containing an iron molecule; each iron binds one molecule of oxygen.

26. Fig. 8.3b, p.146 heme group coiled and twisted polypeptide chain of one globin molecule

27. Useful References for Section 2 The latest references for topics covered in this section can be found at the book companion website. Log in to the book’s e-resources page at www.thomsonedu.com to access InfoTrac articles. • Royal Society of Chemistry: Transport of Oxygen in the Blood • InfoTrac: Hemoglobin Levels Are Testy Issue. New York Daily News, Feb. 12, 2006.

28. Section 3 Hormonal Control of Red Blood Cell Production

29. Hormonal Control of Red Blood Cell Production • Red blood cells form from stem cells located in red bone marrow. • The hormone erythropoietin from the kidneys is the stimulus for stem cell division. • Mature red blood cells have no nuclei and live for only about 120 days. • Macrophages remove old blood cells from the bloodstream; amino acids are returned to the blood, iron is returned to the bone marrow, and heme groups are converted to bilirubin. • Red cell counts remain rather constant at 5.4 million/microliter for males and 4.8 million for females.

30. Hormonal Control of Red Blood Cell Production • A negative feedback loop stabilizes the red blood cell count. • The kidneys monitor oxygen content of the blood; when it drops too low, the kidneys secrete erythropoietin. • Erythropoietin stimulates bone marrow to produce more red blood cells; this increases the ability of the blood to carry oxygen. • As oxygen levels rise, the information feeds back to the kidneys, which stop secreting erythropoietin.

31. 5 3 2 1 5 4 4 3 1 2 Kidney Erythropoietin The kidneys detect reduced O2 in the blood. When less O2 is delivered to the kidneys, they secrete the hormone erythropoietin into the blood. Reduced oxygen in blood Developing red blood cells in red bone marrow Erythropoietin stimulates production of red blood cells in bone marrow. Relieves The additional circulating RBCs increase O2 carried in blood. Increased oxygen in blood The increased O2 relieves the initial stimulus that triggered erythropoietin secretion. RBCs Fig. 8.4, p.147

32. Section 4 Blood Types – Genetically Different Red Blood Cells

33. Blood Types – Genetically Different Red Blood Cells • All cells of the human body have surface proteins and other molecules that serve as “self” identification markers. • Any protein marker that prompts a defensive action is called an antigen. • The human body produces antibodies that recognize markers on foreign cells as “nonself” and stimulate immune reactions.

34. Blood Types – Genetically Different Red Blood Cells • The ABO group of blood types includes key self markers on red blood cells. • ABO blood groups are based on glycoprotein surface markers on red blood cells. • Type A has A markers; type B has B markers. • Type AB has both markers; type O has neither marker. • Depending on ABO blood type, the body will also possess antibodies to other blood types; ABO blood typing is done to prevent incompatible blood types from being mixed.

35. Blood Types – Genetically Different Red Blood Cells • Mixing incompatible blood types can cause the clumping called agglutination. • Type A blood types do not have antibodies against A markers, but they do have antibodies to type B; Type B blood types do not have type B antibodies, but they do have type A antibodies, etc. • A type A person cannot donate blood to a type B person because they are incompatible. • When mixed, markers on the surface of red blood cells (not just the ABO markers) that do not match will cause the blood cells to undergo agglutination, a defense response where the blood cells clump.

36. Table 8.1, p.148

37. Table 8.2, p.151

38. Blood Types – Genetically Different Red Blood Cells • Clumped cells can clog small blood vessels, damage tissues, and cause death. compatible blood cells incompatible blood cells Fig. 8.5b, p. 149

39. Fig. 8.5a, p.149 Donor type B blood Recipient with type A blood Antigen A Antigen B Antibody to type A blood Antibody to type B blood Red blood cells from donor agglutinated by antibodies in recipient’s blood Red blood cells usually burst Clumping blocks blood flow in capillaries Side effects disrupt kidney function Oxygen and nutrient flow to cells and tissues is reduced

40. Fig. 8.5a, p.149 Donor type B blood Recipient with type A blood Antigen A Antigen B Antibody to type A blood Antibody to type B blood Red blood cells from donor agglutinated by antibodies in recipient’s blood Red blood cells usually burst Clumping blocks blood flow in capillaries Side effects disrupt kidney function Oxygen and nutrient flow to cells and tissues is reduced Stepped Art

41. Useful References for Section 4 The latest references for topics covered in this section can be found at the book companion website. Log in to the book’s e-resources page at www.thomsonedu.com to access InfoTrac articles. • InfoTrac: Babies Accept Hearts with All Blood Types. UPI NewsTrack, April 5, 2005.

42. Section 5 Rh Blood Typing

43. Rh Blood Typing • Rh blood typing looks for an Rh marker. • Rh blood typing looks for the presence (Rh+) or absence (Rh-) of antigen on red blood cells. • An Rh- person transfused with Rh+ blood will produce antibodies to the Rh marker.

44. Rh Blood Typing • An Rh- mother who bears an Rh+ child can also become sensitized to the Rh antigen; secondary children may be at risk from maternal antibodies. • In hemolytic disease of the newborn, too many cells may be destroyed and the fetus dies. • Medical treatment (RhoGam) given to the mother after the birth of the first Rh+ baby can inactivate the Rh antibodies.

45. Rh Blood Typing • There are also many other markers on red blood cells. • Hundreds of different blood cell markers are known; most are widely scattered in the human population. • To avoid problems with transfusions, blood undergoes cross-matching to exclude incompatible blood types from being used.

46. Useful References for Section 5 The latest references for topics covered in this section can be found at the book companion website. Log in to the book’s e-resources page at www.thomsonedu.com to access InfoTrac articles. • InfoTrac: Rh Disease: It’s Still a Threat. Contemporary OB/GYN, May 2004.

47. Section 6 New Frontiers of Blood Typing

48. New Frontiers of Blood Typing • Blood + DNA: Investigating crimes and identifying mom or dad. • Blood cell markers can be used to compare evidence from crime scenes to samples taken from possible perpetrators. • Because blood groups are determined by genes, they are a useful source of information about a person’s genetic heritage. • Blood typing can also be used to help determine the identity of a child’s father or mother.

49. New Frontiers of Blood Typing • For safety’s sake, some people bank their own blood. • Even with screening, blood transfusions still carry the risk of being incompatible or potentially contaminated with infectious agents. • In autologous transfusions, individuals pre-donate blood to themselves prior to surgeries in case transfusion is needed. Figure 8.7

50. New Frontiers of Blood Typing • Blood substitutes must also avoid sparking an immune response. • Blood substitutes have potential uses in situations where it is not feasible to perfectly match blood, such as in an ambulance or on the battlefield. • To date, however, substitutes have been difficult to manufacture; OxygentTM is an oxygen carrier that has currently reached the final stages of clinical trials.