1. Human Anatomy and Physiology Blood and hemodynamics

2. Blood composition • Plasma and formed elements • Formed elements • Erythrocytes, leukocytes, platelets

3. Blood composition • Hematocrit • <45% anemia (O2 delivery problems) • >45% polycythemia (circulation problem)

4. Plasma • Contents • 90% water • Protein (albumin acts as a buffer) • Fats, amino acids, salts, gases, enzymes, hormones • Narrow osmolality range

5. Erythrocytes • Manufactured by erythropoiesis • Committed cell: will form a specific cell type • Erythroblasts undergo rapid mitosis • Reticulocytes enter blood stream (2% of blood)

6. Erythropoiesis

7. Erythrocytes • Function: gas exchange Oxy- and deoxyhemoglobin

8. Erythrocytes • Destruction (3 - 4 months) • Trapped in spleen and destroyed by macrophages • Globin is recycled into amino acids • Iron is used to make new RBC’s • Rest of heme group converted to bilirubin • Bilirubin appears in urine and feces

9. Erythrocyte disorders • Athlete’s anemia • Thalassemia Sickle-cell anemia Blood doping among athletes

10. Leukocytes • The only complete cells • Protect against invasion • Move out of blood by diapedesis Move through tissues by amoeboid motion Follow chemical trails by chemotaxis

11. Leukocytes • Types • Granulocytes: contain cytoplasmic granules • Neutrophils, eosinophils basophils • Agranulocytes: without cytoplasmic granules • Lymphocytes, monocytes • Abundance: Never Let Monkeys Eat Bananas

12. Neutrophils • Characteristics • Multilobed (3 - 6 lobes) nucleus • Twice the size of RBC’s • Phagocytose bacteria

13. Eosinophils • Characteristics • Bilobed nucleus • Course granules stain deep red to crimson • Twice the size of RBC’s • Release digestive enzymes to kill worms (too large to be phagocytosed)

14. Basophils • Characteristics • Course, dark purple, black granules • Twice the size of RBC’s • Release histamine (inflammatory chemical), attract other WBC’s to the area

15. Lymphocytes • Characteristics • Large, dark purple nucleus • About the size of RBC’s • Act in immune response

16. Monocytes • Characteristics • Large, dark purple nucleus • Three times the size of RBC’s • Leave blood stream acting to phagocytose viruses and bacteria

17. Platelets • Megakaryocytes (bone) rupture through sinusoid capillaries • Enucleate, age quickly (10 days) • Hemostasis

18. Hemostasis • Phases • Vascular spasm • Vasconstriction reduces blood flow • Platelet plug formation • Platelets swell, and adhere to each other • Coagulation • Blood transformed from liquid to a gel

19. Hemostasis • Phases • Prothrombin activatorformed • Conversion into thrombin • Fibrin seals the hole RBCs and fibrin mesh

20. Blood typing • RBC plasma membranes bear specific glycoproteins recognized by the body • Glycoproteins called agglutinogens • ABO blood group (A, B, AB or O) • O (common), AB (least common)

21. Blood typing

22. Rh blood group • Rh factor: 8 Rh agglutinogens • C, D, E antigens most common • Carrying Rh symbolized by + • Blood groups reported together (i.e., O+)

23. Rheology • The study of blood flow • Viscosity (i.e., polycythemia)

24. Rheology • Flow rate = 1/viscosity

25. Rheology • Flow rate is directly proportional to differences in pressure • F ∞ P1 - P2 or (∆P)

26. Rheology • Flow rate is indirectly proportional to vessel length (F = 1/L)

27. Rheology • Flow rate is directly proportional to the fourth power of the radius of the vessel • F ∞ r4

28. Hemodynamics • Rate of blood flow highest in smallest cross sectional areas • Functional significance Total area Velocity

29. Blood flow • Laminar flow • Continuous (small vessels) • Pulsatile (large vessels)

30. Blood flow • Turbulent flow • Definition (obstruction, sharp turns, high flow rate) • Occurs after aortic and pulmonary valves or valves in veins

31. Compliance • Tendency of blood vessel volume to increase as pressure increases C = ∆V/∆P P1=160 mmHg, P2=120 mmHg, V1=5 l/min. V2=3 l/min. C = 0.05 kPa-1 • Are veins or arteries more compliant ?

32. Compliance 8X more blood 3X more elasticity 24X more compliant