1. 血管功能 夏强， PhD 浙江大学基础医学系

2. 学习目标 学生在学完本部分后，能够： – 列出三种类型的血管，并描述它们的结构与功 能 – 说出循环系统的两个环路，追溯血液从心脏出 发到任意器官、以及回到心脏的路径 – 定义脉搏 – 描述影响动、静脉及毛细血管血压和血流的因 素 – 定义高血压，区分收缩压与舒张压 – 描述淋巴系统的结构与功能

4. ?

5. Functional parts of blood vessels

6. Hemodynamics Blood flow Q=  P/R = (P1-P2)/R Poiseuille Law: Q=  Pr 4 /8  L  : viscosity r: radius of the vessel L: length of the vessel Q=  P/R R = 8  L /  r 4

7. Decreasing the radius of a vessel by one-half its original radius will have what effect upon blood flow to distal portion? A Blood flow will decrease to 50% of original flow. B Blood flow will decrease by 25% of original flow. C Blood flow will decrease to 10% of original flow. D Blood flow will decrease to 6% of original flow.

8. Arterial blood pressure

9. Systolic pressure (SP ，收缩压 ): the maximum arterial pressure reached during peak ventricular ejection Diastolic pressure (DP ，舒张压 ): the minimum arterial pressure just before ventricular ejection begins Pulse pressure (PP ，脉压 ): the difference between SP and DP Mean arterial pressure (MAP ，平均动 脉压 ): the average pressure in the cardiac cycle (=DP+1/3PP)

10. To estimate systolic and diastolic pressures, pressure is released from an inflatable cuff on the upper arm while listening as blood flow returns to the lower arm. 查 DynaMed

11. Blood Pressure Classification Chart CategorySystolic (mm Hg)Diastolic (mm Hg) NormalLower than 120Lower than 80 Prehypertension120 - 13980 - 89 Hypertension Stage 1140-15990-99 Stage 2160 or higher100 or higher Adapted from The Seventh Report on the joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC 7), NIH Publication No. 03-5233, May 2003 The classification chart is based on adults, aged 18 and older, who are not taking high blood pressure medicines and who are not acutely ill. If systolic and diastolic measurements fall into different categories, the higher category should be used to classify the person's blood pressure status. Classification of blood pressure for adults age 18 years and older 中国高血压防治指南 ?

12. 1 2 3 5 4

13. Arterial Pulse

14. In response to the pulsatile contraction of the heart: pulses of pressure move throughout the vasculature, decreasing in amplitude with distance

15. Systematic examination of pulses: Which and what order?Where and how?Why? 1. Radial arteryRadial side of wrist. With tips of index and middle fingers. To assess rate and rhythm. Simultaneously with femoral to detect delay. Not good for pulse character. 2. Brachial arteryMedial border of humerus at elbow medial to biceps tendon. Either with thumb of examiner's right hand or index and middle of left hand. To assess pulse character. To confirm rhythm. 3. Carotid arteryPress examiner's left thumb against patient's larynx. Press back to feel carotid artery against precervical muscles. Alternatively from behind, curling fingers around side of neck. Best for pulse character and, to some extent, left ventricular function. To detect carotid stenosis.carotid stenosis At resuscitation (CPR). 4. Femoral arteryPatient lying flat and undressed. Place finger directly above pubic ramus and midway between pubic tubercle and anterior superior iliac spine. To assess cardiac output. To detect radiofemoral delay. To assessperipheral vascular disease.peripheral vascular disease 5. Popliteal arteryDeep within the popliteal fossa. Compress against posterior of distal femur with knee slightly flexed. Mainly to assess peripheral vascular disease. In diabetics. 6. Dorsalis pedis (DP) and tibialis posterior (TP) arteries (foot) Lateral to extensor hallucis longus (DP). Posterior to medial malleolus (TP). As above. 7. The abdominal aortaWith the flat of the hand per abdomen, as body habitus allows. In peripheral vascular disease. To detect aneurysmal swelling. From: http://www.patient.co.uk/

16. Microcirculation A-V shunt 1 2 3 4 5

17. Arterioles （微动脉） Two major roles: To be responsible for determining the relative blood flow in individual organs at any given MAP To be a major factor in determining MAP

18. Dynamic adjustments in the blood distribution to the organs is accomplished by relaxation and contraction of circular smooth muscle in the arterioles.

19. Local Control of Blood Flow The mechanism independent of nerves or hormones by which organs and tissues alter their own arteriolar resistances, thereby self-regulating their blood flows –Active hyperemia （主动充血） –Flow autoregulation （血流自身调节） –Reactive hyperemia （反应性充血） –Local response to injury （对损伤的局部反应）

20. Active hyperemia and flow autoregulation differ in their cause but both result in the production of the same local signals that provoke vasodilation. Local control of organ blood flow

21. Extrinsic Control Sympathetic nerves （交感神经） Parasympathetic nerves （副交感神经） Noncholinergic, nonradrenergic autonomic neurons (NO or other noncholinergic vasodilator substances) （ NANC ） Hormones (epinephrine, angiotensin II, vasopressin, atrial natriuretic peptide)

22. Sympathetic stimulation of alpha-adrenergic receptors cause vasoconstriction to decrease blood flow to that location. Sympathetic stimulation of beta-adrenergic receptors lead to vasodilation to cause an increase in blood flow to that location.

23. Renin-angiotensin system （肾素 - 血管紧张素系统）

24. ANGII can be produced directly by conversion of angiotensinogen by the tissue plasminogen activator (tPA), cathepsin G and tonin or by hydrolysis of angiotensin I by chymase and cathepsin G. CAGE = chymostatin-sensitive angiotensin II-generating enzyme

25. Vasopressin （血管升压素）

26. Vasodilator factors PGI 2 – prostacyclin （前列环素） EDRF ( endothelium-derived relaxing factor, nitric oxide) EDHF ( endothelium-dependent hyperpolarizing factor) Endothelium-derived vasoactive substances

28. Vasoconstrictor factors – Endothelin-1 （内皮素 -1 ）

29. Diversity among signals that influence contraction/relaxation in vascular circular smooth muscle implies a diversity of receptors and transduction mechanisms. Major factors affecting arteriolar radius

30. From the biologically active substances produced from arachidonic acid which are listed below, select which is a vasodilator and platelet aggregation inhibitor produced by endothelial and smooth muscle cells A Thromboxane A2 B Lipoxin A C Lipoxin B D Leukotriene C4 E Leukotriene D4 F Leukotriene B4 G Leukotriene F4 H Leukotriene E4 I Thromboxane B2 J Prostacyclin (PGI2)

31. Capillaries

32. Six balls in per minute mandates six balls out per minute. Therefore, the velocity of the balls in the smaller tubes is slower. Relationship between total cross-sectional area and flow velocity

33. The capillary is the primary point exchange between the blood and the interstitial fluid (ISF). Intercellular clefts assist the exchange. Capillary walls are a single endothelial cell in thickness.

34. There are many, many capillaries, each with slow-moving blood in it, resulting in adequate time and surface area for exchange between the capillary blood and the ISF.

35. Movement of fluid and solutes into the blood is called absorption. Absorption Filtration Movement of fluid and solutes out of the blood is called filtration.

36. Net filtration pressure (or Effective filtration pressure)

37. Dynamic changes in vasodilation/vasoconstriction in the arterioles regulate downstream pressures and flow rates. Effects of arteriolar vasodilation or vasoconstriction on capillary blood pressure

38. In which of the following lists of blood vessels is the sequence of vessels arranged from highest to lowest total cross-sectional area in the body? A Arteries, arterioles, capillaries, veins B Arterioles, capillaries, arteries, veins C Capillaries, arterioles, veins, arteries D Veins, capillaries, arterioles, arteries E Arteries, veins, arterioles, capillaries

39. Venous pressure and venous return Venous pressure –Peripheral venous pressure （外周静脉压） --the pressure in the peripheral veins –Central venous pressure (CVP ， 中心静脉压 ) -- the pressure in the thoracic vena cava & the right atrium 4~12cmH 2 O

40. Determinants of venous pressure Contraction of venous smooth muscle –Sympathetic neurons –Hormonal and paracrine vasodilators and vasoconstrictors Skeletal muscle pump Respiratory pump

41. Varicose vein （曲张静脉）

42. Skeletal muscle pump Respiratory pump

43. Alterations in “venous return” alter end-diastolic volume (EDV); increased EDV directly increases stroke volume and cardiac output.

44. The Lymphatic System

45. Lymphatic pump

46. Elephantiasis Also known as lymphatic filariasis, this condition occurs when parasitic worms (any of several types of filaria worms) infest the lymphatic system. The filaria are transmitted by mosquitoes to the blood and can build a population in the lymph nodes, blocking fluid drainage from arms, legs, genitals, or breasts. It is called elephantiasis (literally, "elephant condition") because in extreme cases, the arms and legs look like the limbs of an elephant. Elephantiasis affects over a 100 million people around the world. However, most cases are not as extreme as in this photo!

47. Lymph flow from the foot is: A Increased when an individual rises from the supine to the standing position. B Increased when the foot is massaged. C Increased when capillary permeability is decreased. D Decreased when the valves of the leg veins are incompetent. E Decreased in exercise.

48. A summary of dynamic changes in MAP and TPR.

49. Regulation of Cardiovascular Activities 夏强， PhD 浙江大学基础医学系

50. Control of Cardiovascular Activities Nervous Regulation Humoral Regulation Autoregulation

52. Innervation of the heart Cardiac sympathetic nerve Cardiac vagus nerve 1. 起源 origin 2. 节前纤维 preganglionic fiber 3. 外周神经节 ganglion 4. 节后纤维 postganglionic fiber 5. 支配 distribution 6. 递质 neurotransmitter

53. Cardiac autonomic actions Cardiac sympathetic actions – Positive chronotropic effect 正性变时作用 – Positive dromotropic effect 正性变传导作用 – Positive inotropic effect 正性变力作用 Cardiac parasympathetic actions – Negative chronotropic effect 负性变时作用 – Negative dromotropic effect 负性变传导作用 – Negative inotropic effect 负性变力作用

55. Predominance of autonomic nerves

56. Innervation of the blood vessels Vasoconstrictor nerve 缩血管神经 – Sympathetic vasoconstrictor nerve 交感缩血管神经 Vasodilator nerve 舒血管神经 – Sympathetic vasodilator nerve 交感舒血管神经 – Parasympathetic vasodilator nerve 副交感舒血管神 经 – Dorsal root vasodilator nerve 脊髓背根舒血管神经

57. Vasomotor center Located bilaterally mainly in the reticular substance of the medulla and of the lower third of the pons –Vasoconstrictor area –Vasodilator area –Cardioinhibitor area – dorsal nuclei of the vagus nerves and ambiguous nucleus –Sensory area – tractus solitarius

58. Baroreceptor Reflexes Arterial baroreceptors –Carotid sinus receptor –Aortic arch receptor Afferent nerves (Buffer nerves) Cardiovascular center: medulla Efferent nerves: cardiac sympathetic nerve, sympathetic constrictor nerve, vagus nerve Effector: heart & blood vessels

59. Reflex pathway

60. Baroreceptor neurons deliver MAP information to the medulla oblongata’s cardiovascular control center (CVCC); the CVCC determines autonomic output to the heart. i.e., MAP is above homeostatic set point i.e., reduce cardiac output

61. The End.