بنام خدا

1. بنام خدا

2. Blood physiology

3. Components of Whole Blood Plasma(55% of whole blood) Buffy coat:leukocyctes and platelets(<1% of whole blood) Formed elements Erythrocytes(45% of whole blood) Withdraw blood and place in tube Centrifuge 1 2 Figure 17.1

4. Blood Components: Plasma Transports Solutes • Water, ions, trace elements • Gasses: O2 & CO2 • Organic Molecules • Glucose • N–wastes • Proteins • Antibodies • Hormones

6. Blood • Plasma proteins • Albumin: • - Major-Accounts for 60-80% of plasma proteins. • -Provides the osmotic pressure needed to draw H20 from interstitial fluid into capillaries. • .: Maintains blood pressure.

7. Blood • Plasma proteins • Globulins • a globulins and b globulins: • transport lipids and fat soluble vitamins. • g globulins: • antibodies.

8. Blood • Plasma proteins • Fibrinogen: • clotting factor.

9. Blood • Plasma proteins • - liver makes plasma proteins, except for: • - B cells (lympocytes) secrete antibodies

11. Blood Components: Plasma Transports Solutes Figure 16-1: Composition of blood

12. Blood Components: "Blood Count" – % of Each Component Figure 16-2: The blood count

13. Functions • Transportation: • 02 and C02, nutrients, waste • Regulation: • hormones, body temperature • Protection: • blood clotting, immune system

14. Distribution • Blood transports: • Oxygen from the lungs and nutrients from the digestive tract • Metabolic wastes from cells to the lungs and kidneys for elimination • Hormones from endocrine glands to target organs

15. Regulation • Blood maintains: • Appropriate body temperature by absorbing and distributing heat • Normal pH in body tissues using buffer systems • Adequate fluid volume in the circulatory system

16. Protection • Blood prevents blood loss by: • Activating plasma proteins and platelets • Initiating clot formation when a vessel is broken • Blood prevents infection by: • Synthesizing and utilizing antibodies • Activating complement proteins • Activating WBCs to defend the body against foreign invaders

17. Hematopoiesis: Blood Cell Formation • Mostly in bone marrow from stem cells • Rate regulated by cytokines & growth factors

18. Hematopoiesis • Hematopoiesis • - differentiation process which forms blood cells. • - much mitosis, differential gene expression. • - occurs in myeloid tissue (bone marrow of long bones). • Erythropoiesis: formation of RBCs. • Leukopoiesis: formation of WBCs.

20. Hematopoiesis

23. Formation of Leukocytes Figure 17.11

24. 1

25. Fig 2 : Erythropoiesis, the development and maturation of the red blood cells 2

28. Production of Erythrocytes: Erythropoiesis Figure 17.5

30. Hematopoiesis: Blood Cell Formation Figure 16-3: Hematopoiesis

31. Focus on RBCs: • Loose their nucleus • Cytoskeleton – shape • Hemoglobin • Binds O2 in heme group • Binds some CO2 on globulin

32. Erythrocytes (RBCs) Figure 17.3

33. 11a

34. 11b

35. Focus on RBCs: Figure 16-5c: Bone marrow

36. Focus on RBCs: Figure 16-7a, b: Bone marrow

38. Iron Metabolism: Key to Hemoglobin O2 Transport Figure 16-8: Iron metabolism

41. Dietary Requirements of Erythropoiesis • Erythropoiesis requires: • Proteins, lipids, and carbohydrates • Iron, vitamin B12, and folic acid • The body stores iron in Hb (65%), the liver, spleen, and bone marrow • Intracellular iron is stored in protein-iron complexes such as ferritin and hemosiderin • Circulating iron is loosely bound to the transport protein transferrin

42. Erythropoietin Mechanism Imbalance Start Normal blood oxygen levels Stimulus: Hypoxia due to decreased RBC count, decreased availability of O2 to blood, or increased tissue demands for O2 Imbalance Increases O2-carrying ability of blood Reduces O2 levels in blood Erythropoietin stimulates red bone marrow Kidney (and liver to a smaller extent) releases erythropoietin Enhanced erythropoiesis increases RBC count Figure 17.6

45. Erythrocyte Disorders • Anemia – blood has abnormally low oxygen-carrying capacity • It is a symptom rather than a disease itself • Blood oxygen levels cannot support normal metabolism • Signs/symptoms include fatigue, paleness, shortness of breath, and chills

46. Anemia: Insufficient Erythrocytes • Hemorrhagic anemia – result of acute or chronic loss of blood • Hemolytic anemia – prematurely ruptured erythrocytes • Aplastic anemia – destruction or inhibition of red bone marrow

47. Anemia: Decreased Hemoglobin Content • Iron-deficiency anemia results from: • A secondary result of hemorrhagic anemia • Inadequate intake of iron-containing foods • Impaired iron absorption • Pernicious anemia results from: • Deficiency of vitamin B12 • Lack of intrinsic factor needed for absorption of B12 • Treatment is intramuscular injection of B12; application of Nascobal

48. Anemia: Abnormal Hemoglobin • Thalassemias – absent or faulty globin chain in hemoglobin • Erythrocytes are thin, delicate, and deficient in hemoglobin • Sickle-cell anemia – results from a defective gene coding for an abnormal hemoglobin called hemoglobinS (HbS) • HbS has a single amino acid substitution in the beta chain • This defect causes RBCs to become sickle-shaped in low oxygen situations

49. Polycythemia • Polycythemia – excess RBCs that increase blood viscosity • Two main polycythemias are: • Polycythemia vera • Secondary polycythemia