The disorder of local circulation

1. The disorder of local circulation Dr. Philip S.L. Beh Email: philipbeh@pathology.hku.hk

2. Lecture Outline • Overview and revisit basic concepts • Circulatory system • Structure of blood vessels • Components of blood • Oedema • Generalised • Local • Effects on Brain and Lungs • Hemostasis – Normal physiological response • Thrombosis – Abnormal pathological response • Other forms of obstruction • Infarction – Abnormal pathological outcome

3. Overview and Revisit • Circulatory System • Structure of blood vessels • Components of Blood

4. Circulatory System • Heart – Pump • Blood Vessels – Pipes • Artery, Vein, Capillary • Lymphatics – Drainage pipes

5. Properties of circulatory system • Ensure smooth and adequate flow of blood. • Delivers nutrients and oxygen • Removes waste and carbon dioxide

6. Properties of arteries • Aorta • Comes off the heart • Sustains high blood pressures • Elastic but rigid wall • Arteries • Lower blood pressures • Often have muscular wall and can contract

7. Structure of artery Taken from www.sirinet.net/~jgjohnso/ circulation.html

8. Thin wall Some have valves to prevent back-flow of blood Weak ability to contract even if there are muscle fibers in the wall. Dependant on “pumping action of surrounding muscles – particularly of the limbs. Properties of veins

9. Structure of vein Taken from www.sirinet.net/~jgjohnso/ circulation.html

10. Properties of capillary bed • Very thin wall often only one cell-thick and can change to allow blood to pass through into the interstitial space.

11. Taken from Underwood – General and Systemic Pathology

12. Taken from Guyton & Hall – Human Physiology and Mechanisms of Disease

13. Properties of lymphatic channels • Tube-like • Numerous valves • Drains fluid back to blood-stream – passes through at least one lymph-node. • Present in all tissues except • CNS, Eyeballs, Internal Ear, Epidermis of the skin, cartilage and bone.

14. Taken from Guyton & Hall – Human Physiology and Mechanisms of Disease

15. Systemic circulation vs. Pulmonary circulation Taken from Robbins Pathologic Basis of Disease

16. Schematic of lymphatic channels Taken from Colour Atlas of Anatomy – Roden, Yokochi and Lutjen-Drecoll

17. Components of Blood • Plasma – proteins, electrolytes and water • Cells – red blood cells, white blood cells and platelets.

18. Disorders of the Circulatory System • Congestion • Hemostasis • Thrombosis • Emboli • Other obstruction • Ischaemia and infarction

19. Congestion • Distension of blood vessels • May be an active or passive process • Reversible condition

20. Oedema

21. Oedema • Water compartments • Movement of water between the compartments • Causes of oedema • Pulmonary oedema • Cerebral oedema

22. Taken from Guyton & Hall – Human Physiology and Mechanisms of Disease

23. Taken from Underwood – General and Systemic Pathology

24. Taken from Guyton & Hall – Human Physiology and Mechanisms of Disease

25. Taken from Guyton & Hall – Human Physiology and Mechanisms of Disease

26. Taken from Guyton & Hall – Human Physiology and Mechanisms of Disease

27. Taken from Guyton & Hall – Human Physiology and Mechanisms of Disease

28. Taken from Guyton & Hall – Human Physiology and Mechanisms of Disease

29. Taken from Guyton & Hall – Human Physiology and Mechanisms of Disease

30. Taken from Guyton & Hall – Human Physiology and Mechanisms of Disease

31. Taken from Underwood – General and Systemic Pathology

32. Taken from Underwood – General and Systemic Pathology

33. Taken from Underwood – General and Systemic Pathology

34. Taken from Sternberg`s HISTOLOGY for PATHOLOGISTS

35. Taken from Sternberg`s HISTOLOGY for PATHOLOGISTS

36. Taken from Colour Atlas of Anatomy – Roden, Yokochi and Lutjen-Drecoll

37. Taken from Colour Atlas of Anatomy – Roden, Yokochi and Lutjen-Drecoll

38. Taken from Colour Atlas of Anatomy – Roden, Yokochi and Lutjen-Drecoll

39. Taken from Colour Atlas of Anatomy – Roden, Yokochi and Lutjen-Drecoll

40. Hemostasis Diagram from Robbins Pathologic Basis of Diseases

41. Platelet adhesion to von Willebrand’s factor Diagram from Robbins Pathologic Basis of Diseases

42. Hemostasis – Adhesion and Recruitment Diagram from Robbins Pathologic Basis of Diseases

43. Hemostasis – Thrombin activation Diagram from Robbins Pathologic Basis of Diseases

44. Diagram from Robbins Pathologic Basis of Diseases

45. Hemostasis - Plug Diagram from Robbins Pathologic Basis of Diseases

46. Opposing actions Diagram from Robbins Pathologic Basis of Diseases

47. Thrombosis

48. Definition • Thrombus – a blood clot. • Thrombosis – a pathological process whereby there is formation of a blood clot in uninjured vasculature or after relatively minor injury.

49. Definition • Embolus – A detached intravascular solid, liquid or gaseous mass that is carried by the blood to a site distant from its point of origin.

50. Virchow’s Triad • Pathogenesis of a Thrombus Endothelial injury Abnormal blood flow Hypercoagulability • Primary (genetic) • Secondary (acquired)