1. Unit 10: Blood

2. Composition of blood Only fluid connective tissue It has both solid and liquid components

3. Living components of blood Living blood cells are called formed elements 45% of blood

4. Non-living components of blood Nonliving fluid matrix is called plasma 55% of blood

5. Physical characteristics of blood Sticky opaque fluid Metallic taste due to the salts The brighter the color the more oxygen-rich pH of 7.35 to 7.45 8% of human body weight

6. Plasma The non-living aspect of blood 90% water 10% salts and proteins

7. Function of plasma Transport various substances around the body Helps distribute body heat evenly throughout the body

8. Plasma continued DO NOT WRITE: There are various constituents of plasma (things that make plasma up) The following section is the list of key constituents within plasma, and their specific role in the body

9. Water Solvent for carrying other substances

10. Salts (electrolytes) Osmotic balance pH buffering Regulation of membrane permeability

11. Plasma Proteins Osmotic balance pH buffering Blood clotting Defense Lipid transport

12. Substances transported by blood Nutrients Waste products from metabolism Respiratory gases

13. Formed Elements

14. What are formed elements? Blood cells and platelets LIVING constituents of blood

15. Erythrocytes Aka: Red Blood Cells ~ 4-6 million per mm 3 Function: carry oxygen to all cells in the body

16. Anatomy of Erythrocytes Lack a nucleus and contains very few organelles sacs of hemoglobin, an iron containing protein More hemoglobin = better oxygen transport

17. Shape of erythrocytes Bulky outer ring with a depressed center biconcave This depression helps carry oxygen

18. Leukocytes Aka: White Blood Cells ~4,000 to 11,000 per mm 3 Critical to body defenses against disease caused by bacteria, viruses, parasites, and tumors

19. Anatomy of Leukocytes Only blood cell to contain nuclei and organelles Because there are various types of WBC, there is no general shape

20. How do they function in the blood? WBC’s can jump from the blood stream to the other organs in order to carry out their function They use this method for inflammatory and immune responses

21. How do WBC’s know where to go? By a process is called positive chemotaxis When cells are damaged or destroyed, they release the chemicals within them The WBC’s are able to locate this chemical and seek it out

22. Neutrophils: 40-70% of WBC Active phagocytes # increases rapidly during acute infections

23. Eosinophils: 1-4% of WBC Kill parasitic worms, increase during allergy attacks

24. Basophils: 0-1% of WBC Contains histamine, discharged at sites of inflammation

25. Lymphocytes: 20-40% of WBC B-lymphocytes – produce antibodies T-lymphocytes- graft rejection, fighting tumors & viruses

26. Monocytes 4-8% of WBC Become macrophages Long term “clean-up team”

27. Platelets ~300,000 per mm 3 They are actually incomplete pieces of cells They function in blood clotting

28. What are platelets made out of? A complex, multinucleate cell ruptures and releases thousands of fragments of itself Once they explode, they attempt to reattach to each other Forms a net that blood may clot onto

29. Hematopoiesis blood cell formation Occurs in bone marrow of long bones Once finished, the new blood cells are released into the surrounding blood vessels

30. What causes hematopoiesis? Each blood type is produced in response to changing stimuli Effects for each blood cell type and platelets will be looked at

31. Before hematopoiesis: Stem cells* called hemocytoblasts are found in the bone marrow of bones These cells are activated by specific hormones which determine what type of cell it will become *A stem cell is a cell that can become any type of cell initially. Once its path is set, however, it MUST become what has been determined. For example, a hemocytoblast is activated to become a RBC, once this happens, it can never be a WBC or platelet

32. Hematopoiesis of Erythrocytes

33. Why cant RBC’s just split to make new cells? RBC’s are anucleate, so they cannot repair, grow, or divide As they age, they become rigid and fall apart Life expectancy of RBC: 100-120 days

34. What happens to old RBC’s? Remains of old and broken RBC’s are eliminated by phagocytes in the body

35. How does the body replace the old RBC’s? Hematopoiesis This replaces the RBC’s continuously throughout life This occurs over a 4-step process

36. Step 1: stimulus Decreased RBC count Decreased availability of O 2 to blood Increased tissue demands for O 2 all these lead to decreased O 2 levels in blood

37. Step 2: Kidneys release the hormone erythropoietin

38. Step 3 Increased levels of erythropoietin stimulates the bone marrow to increase production of RBC’s

39. Step 4 The increased RBC count raises the amount of O 2 distributed to the blood and tissues Homeostasis is restored

40. Hematopoiesis of Leukocytes

41. How does hematopoiesis of WBC’s occur? The exact same way as for RBC’s, with only 2 changes:

42. WBC hematopoiesis 1. The new stimuli are chemicals released when cells are inflamed or destroyed, as well as exposure to bacteria and toxins

43. WBC hematopoiesis continued 2. The hormones that stimulate the bone marrow to produce WBC’s are called interleukins

44. What is hemostasis? stoppage of blood flow It occurs after a blood vessel is broken

45. Phases of Hemostasis 3 phase process that completely stops blood loss and fills the hole in the blood vessel

46. phase 1: Vascular Spasms Damage occurs which spreads platelets out. Once platelets spread, they become sticky and attach to the damage site The platelets then release chemicals to attract other platelets, and to induce spasms of the blood vessel Constricts the blood vessels and reduces blood loss

47. phase 2: Platelet Plug Formation Once the platelets have attracted enough of each other onto the damaged tissue, a plug of platelets is formed This prevents blood loss, but is very weak and easily broken

48. phase 3: Coagulation Threadlike proteins called fibrin then connect the edges of the ruptured blood vessel to begin the healing process. This occurs OVER the platelet plug

49. How long does this process take? Blood clotting usually takes only 3-6 minutes

50. What happens after the clot is formed? Immediately after the clot forms, the healing factors are disabled This prevents too much blood from clotting, which can lead to strokes The extra clot is then broken down

51. Blood Types

52. Why do we have different blood types? Our RBCs have different molecules attached to them Each person’s molecules are unique These molecules are called antigens

53. Antigens o Molecules that, when introduced into the body, triggers the immune system to kill the new antigen Our bodies naturally produce some antigens, they are found on our RBCs

54. Since we all have different antigens on our RBCs, our bodies can tolerate our own blood, but certain blood types are lethal to other people.

55. Are all foreign antigens lethal to us then? There are only 3 main RBC antigens that are lethal to us: Antigen A Antigen B Rh antigen The occurrence of these antigens in our blood determine what blood type we are

56. How does our body fight the antigens? Anti-A and Anti-B antibodies are located in the plasma Anti-A antibodies will destroy RBCs with A antigens Anti-B antibodies will destroy RBCs with B antigens

57. Blood group types 4 types based off the A and B antigens located on the RBCs

58. Type 1: AB This blood type has both A and B antigens Therefore, there are NO antibodies in the plasma This blood type may receive A, B, AB, and O type blood Universal reciever

59. Type 2: B This blood type has only B antigens Therefore, there are anti-A antibodies in the plasma This blood type may receive B and O type blood

60. Type 3: A This blood type has only A antigens Therefore, there are anti-B antibodies in the plasma This blood type may receive A and O type blood

61. Type 4: O This blood type has NO antigens Therefore, there are anti-A and anti-B antibodies in the plasma This blood type may receive only O blood type Universal donor

62. Rh factor Rh is a different type of antigen that is NOT produced naturally by the blood of Rh negative people The immune system produces Rh antibodies only when exposed to the Rh antigen

63. How do we receive the Rh antigen? The Rh antigens are passed down genetically Rh antibodies are made by our immune system when exposed to the Rh antigen This is the + or – sign you see in your blood type