1. PowerPoint ® Lecture Slides prepared by Janice Meeking, Mount Royal College C H A P T E R Copyright © 2010 Pearson Education, Inc. 17 Blood Modified by: Olga E. Vazquez

2. Copyright © 2010 Pearson Education, Inc. Cardiovascular System Cardio = heart Vascular = blood vessels Consists of three interrelated components: Blood Heart Blood vessels We will now examine the blood.

3. Copyright © 2010 Pearson Education, Inc. Topics Discussed Today Blood as connective tissue Physical characteristics and volume of blood Functions of blood Blood components Plasma Formed elements Hematopoiesis

4. Copyright © 2010 Pearson Education, Inc. Blood Blood is unique from person to person Health care professionals routinely examine and analyze its differences through various blood tests to determine the causes of different diseases. Hematology = study of blood

5. Copyright © 2010 Pearson Education, Inc. Blood: An Overview Blood is the only fluid tissue in the body. Even though it might seem like a homogeneous liquid, the microscope reveals 2 components: Cellular component Liquid component What type of tissue is blood classified as?

6. Copyright © 2010 Pearson Education, Inc. Blood: An Overview Blood is a specialized type of connective tissue in which living blood cells, the formed elements (cells), are suspended in a nonliving fluid matrix called plasma.

7. Copyright © 2010 Pearson Education, Inc. Blood: An Overview Blood cells carry oxygen and nutrients to our body’s tissues, and remove Carbon Dioxide and other wastes, and take them to places to be removed from the body.

8. Copyright © 2010 Pearson Education, Inc. Physical Characteristics and Volume Total blood volume: 8% of body weight Average volume in healthy males: 5-6 L (~ 1.5 gallons) Average volume in healthy females: 4-5 L (1.05 to 1.32 gallons)

9. Copyright © 2010 Pearson Education, Inc. Physical Characteristics and Volume Blood is more dense than water and about 5 times more viscous. Why?

10. Copyright © 2010 Pearson Education, Inc. Viscosity Although plasma is mostly water, it also contains other molecules such as electrolytes, proteins (especially albumin and fibrinogen), and other macromolecules. The addition of formed elements to the plasma (red cells, white cells, and platelets) further increases the viscosity. Of these formed elements, red cells have the greatest effect on viscosity under normal conditions. Temperature

11. Copyright © 2010 Pearson Education, Inc. Functions Blood performs a number of functions, all concerned in one way or another with: Distribution Regulation Protection

12. Copyright © 2010 Pearson Education, Inc. Functions There are six functions: 1. Transportation O 2 lungs → cells CO 2 cells → lungs Nutrients → cells waste from cells → kidneys (excretion!)

13. Copyright © 2010 Pearson Education, Inc. Functions 2. Defense White blood cells – fight disease blood proteins – antibodies (identification)

14. Copyright © 2010 Pearson Education, Inc. Functions 3. Temperature regulation - absorbs and distribute heat throughout body and skin 4. Prevents loss of blood – blood clots 5. Hormone movement – endocrine gland → cells 6. Regulates pH (our acid/base balance in our bodies) – through buffers

15. Copyright © 2010 Pearson Education, Inc. Components of Blood If a sample of blood is spun in a centrifuge, the heavier formed elements are packed down by centrifugal force and the less dense plasma remains at the top.

16. Copyright © 2010 Pearson Education, Inc. Components Bottom – erythrocytes (what are they?) Erythro = red Buffy coat – whitish layer present at the erythrocyte- plasma junction Contains platelets and leukocytes (white blood cells) Plasma

17. Copyright © 2010 Pearson Education, Inc. Plasma Makes up 55% of blood Although is made up of about 90% water, plasma contains over 100 different dissolved solutes including gases, hormones, waste, etc.

18. Copyright © 2010 Pearson Education, Inc. Plasma Contains proteins Contains electrolytes Contains wastes to be taken away Contains water

19. Copyright © 2010 Pearson Education, Inc. Components of Whole Blood

20. Copyright © 2010 Pearson Education, Inc. Formed Elements The formed elements are present in the buffy coat and the bottom red layer. In other words the formed elements are the red blood cells, white blood cells, and platelets (platelets help form clots)

21. Copyright © 2010 Pearson Education, Inc. Components of Whole Blood Figure 17.2

22. Copyright © 2010 Pearson Education, Inc. Formed Elements These cells have unusual features. Two of the three are not even true cells. Why? RBC’s have no nuclei or organelles, and platelets are cell fragments. Only leukocytes are true cells Most of the formed elements survive in the bloodstream for only a few days. Most blood cells do not divide.

23. Copyright © 2010 Pearson Education, Inc. Formed Elements Erythrocytes normally constitute 45% of the total volume of blood. This percentage is known as hematocrit (“blood fraction”). In males and females, this percentage might differ: males: 47% ± 5% females: 42% ± 5%

24. Copyright © 2010 Pearson Education, Inc. Formed Elements RBC or erythrocytes are involved in gas transport Carry O 2 Carry 20% of CO 2

25. Copyright © 2010 Pearson Education, Inc. Formed Elements WBC or leukocytes have many specialized functions. Together with platelets, leukocytes contribute less than 1% of blood volume. Immunity T cells, B cells, neutrophils, macrophages Most abundant – neutrophils

26. Copyright © 2010 Pearson Education, Inc. Formed Elements Platelets Cell fragments Encourage clot formation

27. Copyright © 2010 Pearson Education, Inc. Formed Elements Formation Hematopoiesis (hemato = blood, poiesis = to make) Process in which formed elements of the blood develop Erythropoiesis Leukopoiesis Before birth it occurs Yolk sac Later in the liver, spleen, thymus and lymph nodes Last 3 months of gestation in the red bone marrow

28. Copyright © 2010 Pearson Education, Inc. Hematopoiesis During childhood (up to 5 years) occurs in the epiphysis of almost all long bones. In adults it occurs also in flat and irregular bones such as the skull, sternum, hip bone, ribs, and vertebra. Formed element production in adult’s long bones occurs in the humerus and femur.

29. Copyright © 2010 Pearson Education, Inc. Checking Understanding Explain why blood is classified as a connective tissue What is the average blood volume in human adult? What are the two components of the blood? Why blood is more viscous than water? List three major functions of blood and provide an example of each. Name the formed elements. Why are they elements instead of cells? What is the hematocrit? What is the normal value?

30. Copyright © 2010 Pearson Education, Inc. Red Blood Cells Erythrocytes Erythro = Cyte = The erythrocyte is an excellent example of complementarity of structure and function. Each structural characteristic contributes to its gas transport functions.

31. Copyright © 2010 Pearson Education, Inc. Structural Characterstics Its small size and biconcave shape provides 30% more surface area than other spherical cells. Why is this important?

32. Copyright © 2010 Pearson Education, Inc. Structural Characteristics No nucleus (anucleate) or organelles The red blood cell carries a protein called “hemoglobin” that carries the oxygen to our body parts. Hemoglobin is made partly with iron.

33. Copyright © 2010 Pearson Education, Inc. Structural Characteristics Major function of RBC is to transport hemoglobin. Erythrocytes are over 97% hemoglobin. This is why RBC could be called “bags” of hemoglobin.

34. Copyright © 2010 Pearson Education, Inc. Hemoglobin It’s the protein that makes RBC red. Binds easily and reversibly to oxygen Oxygen moves in the blood bound to hemoglobin Normal values of hemoglobin 14-20 g/100ml in infants 13-18 g/100ml in adult males 12-16 g/100ml in adult females

35. Copyright © 2010 Pearson Education, Inc. Hemoglobin A single RBC contains about 250 million hemoglobin molecules. So, each RBC can hold about 1 billion molecules of O 2.

36. Copyright © 2010 Pearson Education, Inc. Erythropoiesis Erythropoiesis needs to be controlled so there is a balance between RBC production and destruction. New cells are made at a rate of more than 2 million per second in healthy people.

37. Copyright © 2010 Pearson Education, Inc. Erythropoietin Hormone effects: Hormones produced in the kidney and liver Stimulates red bone marrow to increase rate of cells

38. Copyright © 2010 Pearson Education, Inc. Figure 17.6, step 1 Homeostasis: Normal blood oxygen levels Stimulus: Hypoxia (low blood O 2 - carrying ability) due to Decreased RBC count Decreased amount of hemoglobin Decreased availability of O 2 1 IMBALANCE

39. Copyright © 2010 Pearson Education, Inc. Figure 17.6, step 2 Kidney (and liver to a smaller extent) releases erythropoietin. Homeostasis: Normal blood oxygen levels Stimulus: Hypoxia (low blood O 2 - carrying ability) due to Decreased RBC count Decreased amount of hemoglobin Decreased availability of O 2 1 2 IMBALANCE

40. Copyright © 2010 Pearson Education, Inc. Figure 17.6, step 3 Kidney (and liver to a smaller extent) releases erythropoietin. Erythropoietin stimulates red bone marrow. Homeostasis: Normal blood oxygen levels Stimulus: Hypoxia (low blood O 2 - carrying ability) due to Decreased RBC count Decreased amount of hemoglobin Decreased availability of O 2 1 2 3 IMBALANCE

41. Copyright © 2010 Pearson Education, Inc. Figure 17.6, step 4 Kidney (and liver to a smaller extent) releases erythropoietin. Erythropoietin stimulates red bone marrow. Enhanced erythropoiesis increases RBC count. Homeostasis: Normal blood oxygen levels Stimulus: Hypoxia (low blood O 2 - carrying ability) due to Decreased RBC count Decreased amount of hemoglobin Decreased availability of O 2 1 2 3 4 IMBALANCE

42. Copyright © 2010 Pearson Education, Inc. Figure 17.6, step 5 Kidney (and liver to a smaller extent) releases erythropoietin. Erythropoietin stimulates red bone marrow. Enhanced erythropoiesis increases RBC count. O 2 - carrying ability of blood increases. Homeostasis: Normal blood oxygen levels Stimulus: Hypoxia (low blood O 2 - carrying ability) due to Decreased RBC count Decreased amount of hemoglobin Decreased availability of O 2 1 2 3 4 5 IMBALANCE

43. Copyright © 2010 Pearson Education, Inc. Analyzing How might your hematocrit change if you move from a town at sea level to a high mountain village?

44. Copyright © 2010 Pearson Education, Inc. Destruction of Erythrocytes Red blood cells have a useful life span of 100 to 120 days, after which they become trapped and fragment in smaller circulatory channels, particularly in those of the spleen. In the red pulp of the spleen, RBC rupture when they try to squeeze through because of their fragile old membrane. For this reason, the spleen is sometimes called the “red blood cell graveyard

45. Copyright © 2010 Pearson Education, Inc. Anemia Any decrease in blood’s oxygen-carrying capacity is known as anemia. Causes: Insufficient number of RBC Low hemoglobin content Abnormal hemoglobin One of the major effects of anemia is the greatly increased work load on the heart.

46. Copyright © 2010 Pearson Education, Inc. RBC’s have antigens (identifiers) on them. The presence or absence of these antigens tell us what blood type we have. Human Blood Groups

47. Copyright © 2010 Pearson Education, Inc. Markers on RBC If there are no blood type antigens, you have type O blood. If you have B type antigens, you have type B blood. If you have A type antigens, you have A type blood. What about people with type AB blood? People that carry the “D” antigen are Rh +. If they do not have the antigen, they are Rh-

48. Copyright © 2010 Pearson Education, Inc. ABO Markers

49. Copyright © 2010 Pearson Education, Inc. Rh Factor There are 45 different types of Rh agglutinogens. Three of which (C, D, and E) are common About 85% of Americans are Rh positive, which means they carry the D antigen. Presence of the Rh agglutinogens on RBCs is indicated as Rh + As a rule, a person’s ABO and Rh blood groups are reported together, for example, O +, A -, and so on.

50. Copyright © 2010 Pearson Education, Inc.

51. Rh Factor and Pregnancy Rho GAM Injection of anti-Rh antibodies given soon after every delivery, miscarriage, abortion-binds Inactivates fetal Rh antigens so mother’s immune system doesn’t respond

52. Copyright © 2010 Pearson Education, Inc. Checking Your Understanding What is the main function of RBC? What organ is the red blood cell graveyard? Mrs. D has type A blood and is Rh+. So, she has A+ blood. What antigens (ID markers) are carried on her blood? Mrs. D’s husband has type A- blood. What does this mean?