CHAPTER 4 CIRCULATI 血液循环 Prof. Wang Ting huai Department of Physiology
SECTION 3 VASCULAR PHYSIOLOGY 血管生理
弹性储器血管:主动脉和大动脉 分配血管:中等动脉 阻力血管:小动脉和微动脉 动脉 毛细血管 交换血管 静脉 容量血管
Ⅰ. Functional properties of different blood vessels 不同血管的功能特征 1 Ⅰ. Functional properties of different blood vessels 不同血管的功能特征 1. Artery: 动脉 A. Aorta and large artery (windkessel vessel ) 主动脉和大动脉,又称弹性贮器血管
pressure reservoir 压力储存器 maintain the continual blood fluid in the artery system. 维持动脉系统内连续的血流 Low resistance vessel 低阻力血管 transport blood to every apparatus of the globle body 运送血液到全身各个器官
B. Middle artery: carry blood to arterioles (distribution vessel) 中动脉 :运送血流至小动脉,又称分配血管。
C. Small artery and arteriole — resistance vessels 小动脉和微动脉-阻力血管 Small artery and arteriole are the main position of organism to regulate the organ blood flow and the redistribution of blood among apparatus. The diameter of resistance vessels are regulated by neurohormonal factors. 小动脉和微动脉是机体调节器官血流量和器官之间血液重新分配的主要部位,其血管的口径受神经体液因素的调节 。
2. Capillary vessels: exchange vessels 毛细血管:交换血管 Blood flow from arteriole to venules by passing capillary to carry out the exchange of substances between blood and interstitial fluid. 血流通过毛细血管从小动脉到小静脉,完成 血液和组织液的物质交换。
Precapillary sphincter 毛细血管前括约肌 Function: Control of inflow of capillaries 作用:控制毛细血管的流入量。 A-V shunt (anastomosis) 动静脉短路(吻合) Function:Blood flows directly from arteriole to veinule through A-V shunt . 作用:血液通过动静脉吻合由微动脉直接到达微静脉。
3. Venous Vessels ( capacitance vessel) 静脉血管(容量血管) Large vein,vena cava,venule,veinule 大静脉,腔静脉,小静脉,微静脉 Blood reservoir 血液储存库(60%~70%) Big compliance 顺应性大 Low mean venous pressure 平均静脉压低(2mmHg) Venous valve 静脉瓣
Ⅱ. Hemodynamics 血流动力学 Blood flow, resistance to blood flow and pressure 血流量,血流阻力和血压 1. Blood flow: Blood volume passing a given section in the cardiovascular system per unit time (ml/s). 血流量:单位时间流过血管某一横截面的 血量(ml/s)。
P1-P2 A. Q = ———— R Q :blood flow(血流量) P1-P2:the dp of the two vessels ends (血管两端压力差) R: resistance of blood flow (血流阻力) B. Poiseulle’s law for laminar flow Δp πΔpr4 F = ———— = ———— 阻力 8ηL L :血管长度 η :血液黏度 r veinule:血管半径
The mode of blood flowing in the blood vessels can be classified into Laminar flow and turbulent flow. 血液在血管内的流动方式可以分为层流和湍流。
Empirical equation(经验公式) Reynold’s number---Reynold数: NR =ρDV/η ρ(rho): density of fluid 液体密度 D: diameter of the tube 管径 V: velocity of flow 流速 NR< 2000 NR>2000 laminar flow turbulent flow 层流 湍流
Laminar flow Turbulent flow 层流 湍流 The same flow direction The different flow direction 流动方向一致 流动方向不一致 no vibration Vibration 无振动 有振动 no sound Sound 无声音 有声音 Wasteful energy less Wasteful energy more 耗能少 耗能多
泊肃叶定律适于层流情况。在湍流情况下,泊肃叶定律不再适用,血流量不是与血管两端的压力差成正比,而是与压力差的平方根成正比。 Poiseulle’s law for laminar flow conforms to laminar flow but turbulent flow.Under turbulent flow, the blood flow is not in direct proportion to the bp of the two ends of vessels, however to its square root. 泊肃叶定律适于层流情况。在湍流情况下,泊肃叶定律不再适用,血流量不是与血管两端的压力差成正比,而是与压力差的平方根成正比。
2. Resistance to blood flow: 血流阻力 P1-P2 8ηL F = ——— R = ——— R πr4 Resistance comes from external friction (L, r) ,internal friction (η). Total peripheral resistance is mainly determined by arterioles(60~70%). 阻力来自外摩擦(L,r)和内摩擦(η), 60-70%的总外周阻力主要来自微动脉。
The blood flow of organ is determined by mean arterial blood pressure and blood resistance. The diameter of arterioles is the determining factor to regulate the redistribution of blood flow of organs. 一个器官血流量的多少主要受平均动脉压和血管半径的影响。小动脉和微动脉口径的变化是调节器官血流量和器官之间血液重新分配的最主要因素。
Blood pressure 血压 Two requirements for blood pressure formation: 血压形成的两个条件: A. Blood filling in cardiovascular system 心血管系统血液充盈 Mean circulatory filling pressure ∽ blood volume ——————— = 7mmHg vascular volume 血液容量 循环系统平均充盈压 ————— = 7mmHg 血管容量
B. Cardiac ejection 心脏射血 kinetic energy: push the blood to flow Cardiac Contraction Energesis potential energy: vessel wall expand Cardiac relaxation:large artery elasticity recovery Percentage potential energy kinetic energy : Push blood to continuously flow forward
动能:推动血液流动 心脏收缩 释放能量 势能:血管壁扩张 心脏舒张:大动脉弹性回缩 部分势能 动能:推动血液继续向前流动
Ⅲ. Arterial Blood Pressure 动脉血压 1. Normal value 正常值
Systolic Pressure 收缩压 100~120 13.3~16 Normal value mmHg kPa Systolic Pressure 收缩压 100~120 13.3~16 Diastolic Pressure 舒张压 60~80 8~10 Pulse Pressure 脉压 30~40 4.0~5.3 MAP 平均动脉压 100 13.3 MAP = DP + 1/3 (pulse P)
A. D n fluctuating rules of blood pressure 血压的昼夜波动 Double peaks and double valley (day rhythm) 双峰双谷(日节律)
Lowest at 2 to 3 o’clock in the morning 凌晨2 ~ 3时最低 One Peak during 6 to 10 in the morning 上午6 ~ 10时高 Another peak during 4 to 8 in the afternoon 下午4 ~ 8时高 Lowing down after 8 o’clock in the evening 晚上8时缓慢下降
B. Diagnosis criteria of hypertension 高血压的诊断标准 Catalogues SP DP Normal <120 <90 prophase 120~139 80~89 1st phase 140~159 90~99 2nd phase ≥160 ≥100 The JNC 7 Report JAMA. 2003;289:(DOI 10.1001/jama.289.19.2560.
高血压分类 收缩压 舒张压 (mmHg) (mmHg) 正常 <120 和 <90 高血压前期 120 ~139 或 80 ~ 89 1 期高血压 140 ~159 或 90 ~ 99 2 期高血压 ≥160 或 ≥100
C. Pressure of different vessels of systemic circulation 体循环不同血管的血压
平均压(mmHg) 主动脉 100 动脉(3mm) 95 微动脉起始端 85 微动脉末端 55 毛细血管起始端 30
Fall of blood pressure is in direct proportion to the resistance of blood flow,and the BP decreases significantly in the arteriole ,where the blood flow resistence is the biggest. 血压降落与血流阻力成正比,在血流阻力最大的微动脉段,血压降落最为显著。
D. Arterial pressure curves recorded from different sites of systemic circulation(dog) 体循环不同部位血压波波形
Arch lower abdomen iliac knee ankle 主动脉弓 下腹部 髂部 膝部 踝部 ascending branch onsets later 升支起始延迟 waveshape sharper 波形变窄 amplitude higher 幅度增高 reentry wave appears 出现折返波
2. Determinants of arterial blood pressure 动脉血压的决定因素 A 2. Determinants of arterial blood pressure 动脉血压的决定因素 A. arterial blood volume 动脉血容量 It is determined by ejection volume and peripheral resistance. 由心脏射血量和外周阻力决定。
B. arterial compliance 动脉顺应性 顺应性=ΔV/Δp In normal condition ,the elasticity of arterial can buffer the fluctuations of BP,and change the blood ejected into arterial to continuous blood flow . 正常时,动脉的弹性对血压起“缓冲”作用,维持 一定的收缩压和舒张压,使心室间断的射入动脉 的血流变成动脉的连续性血流。
If we assume that arterial compliance remains constant arterial blood pressure will depend on arterial blood volume and vascular volume. 假定动脉顺应性保持恒定,则动脉血压取决于动脉血量和血管容量。 Blood volume BP ∽ ———————— vascular volume
Arterial blood volume is determined by the rate of inflow and outflow of arterial system. 动脉血容量取决于动脉系统流入量与流出量 。 Rate of inflow:cardiac output 流入量:心输出量 Rate of outflow: resistance and BP 流出量: 血流阻力和动脉血压
3. Factors affecting arterial pressure 影响动脉血压的因素 A 3. Factors affecting arterial pressure 影响动脉血压的因素 A. stoke volume 每搏输出量 B. heart rate 心率 C. peripheral resistance 外周阻力 D. Compliance of aorta and large artery 主动脉和大动脉的顺应性 E. circulatory blood flow 循环血量
影响动脉血压的因素 影响因素 变化 收缩压 舒张压 脉压 备 注 每搏量 增加 ↑↑ ↑ 增大 收缩压的高低主要反映每搏量多少。 减少 ↓↓ 备 注 每搏量 增加 ↑↑ ↑ 增大 收缩压的高低主要反映每搏量多少。 减少 ↓↓ ↓ 减小 外周阻力 增大 ↑ ↑↑ 减小 舒张压的高低主要反映外周阻力大小。 减小 ↓ ↓↓ 增大 心率(40~180次/分) 加快 ↑ ↑↑ 减小 心率的快慢主要影响舒张压。心率过快或过慢血压都将下降。 减慢 ↓ ↓↓ 增大 大动脉的顺应性 下降 ↑ ↓ 增大 大动脉弹性下降致弹性贮器效应减弱。 循环血量与血管容积的比例 变大 ↑ ↑ 循环血量增加或血管容积减小。 减小 ↓ ↓ 循环血量减少或血管容积增大。
All the above-mentioned factors of influencing BP is deduced when assuming other influencing factor keeping stable.Actually , the fluctuations of BP under certain physiological condition is always the summation of many factors functions mutually. 上述影响动脉血压的各种因素,都是在假定其他影响因素不变的前提下,分析某一因素变化时对动脉血压可能发生的影响。实际上,某种生理情况下动脉血压的变化,往往是各种因素相互作用的总和结果。
IV.Venous pressure and venous return 静脉血压和静脉回流 1. Central venous pressure 中心静脉压 (4-12 cm H2O) Affect factors:影响因素 A. Heart pump action 心脏泵功能 B. Venous return velocity 静脉回流速度
CVP:an index of cardiovascular function 反映心血管功能的一项指标 CVP ↓:输液量不足 CVP ↑:输液过快或心脏射血功能不全
2. Peripheral venous pressure 外周静脉压 Effect of gravity on venous pressure 重力对静脉压的影响 Orthostatic hypotension 直立性低血压
3. Venous return and affecting factors 静脉回流及影响因素 A. Mean circulatory filling pressure 循环系统平均充盈压 B. Cardiac contractility 心肌收缩力 C. Sympathetic nerve 交感神经 D. Muscle pump 肌肉泵 E. Thoracic pump 呼吸泵
影响静脉回心血量因素 影响因素 变化 静脉回心血量 作 用 机 制 体循环平均充盈压 ↑ 外周静脉压与中心静脉压差↑ ↓ 外周静脉压与中心静脉压差↓ 心脏收缩力量 心舒期抽吸力↑ 心舒期抽吸力↓ 交感神经 兴奋 NA释放, 静脉收缩, 静脉压↑ 抑制 NA释放↓, 静脉收缩↓ 骨骼肌的 挤压作用 肌肉运动↑ 肌肉收缩期挤压和舒张期抽吸作用↑。紧张收缩则静脉回流↓ 肌肉运动↓ 呼吸运动 胸内负压↑ 吸气时,胸内负压↑,腔静脉扩张,静脉回流增加;呼气时则↓ 胸内负压↓
V. Microcirculation 微循环
Microcirculation is the blood circulation between arteriole and veinule.The microcirculation is the place where the blood and interstitial fluid to carry out the exchange of substances. 微循环是指微动脉和微静脉之间的血液循环。 微循环是血液和组织之间进行物质交换的场所。
Architecture of microcirculation 微循环的结构 A. Fundamental composition 基本构成 Arteriole →metarteriole → precapillary sphincter →true capillary→ venule 微动脉→后微动脉→毛细血管前括约肌 →真毛细血管→微静脉
B. Preferential channel or thoroughfare 通血毛细血管(直捷通路) Arteriole →metarteriole → Preferential channel →venule 微动脉→后微动脉→通血毛细血管→微静脉 The blood flows into veins quickly through microcirculation ,and it’s can be easily found in skeletal muscle. 血液通过微循环迅速进入静脉,骨骼肌中多见。
C. A-V anastomosis or A-v shunt 动静脉吻合或动静脉短路 Arteriole →venule 微动脉→微静脉 Participate in thermoregulation 参与体温调节 infection or toxic shock open more, and the oxygen deficiency aggravate. 感染或中毒性休克时大量开放,加重组织缺氧。
Hemodynamic of microcirculation 微循环的血流动力学 A Hemodynamic of microcirculation 微循环的血流动力学 A. big cross section area 横截面积大 slow velocity of blood flow 血流速度缓慢 The substances can be thoroughly exchanged between blood and interstitial fluid. 有利于血液与组织液在毛细血管进行物质交换。
B. capillary pressure depends on precapillary resistance / postcapillary resistance. 毛细血管压力取决于毛细血管前阻力与毛细 血管后阻力的比值。 The blood volume of microcirculation is in direct proportion to the dp of arteriole and veinule,and in inverse proportion to the whole resistance of microcirculation. 微循环的血流量与微动脉和微静脉之间的血压差成正比,与微循环中血流总阻力成反比。
C. alternate opening and closing of capillaries. 毛细血管交替性收缩和舒张 vasomotion activity 血管舒缩活动 (5-10次/min) Vasomotion activity is maily concerned with the metabolic activity of regional tissues .The blood flow of microcirculation conforms to the level of metabolic activity. 血管舒缩活动主要与局部组织的代谢活动有关。 微循环的血流量和组织的代谢活动水平相适应。
3. Exchange of substances between blood and interstitial fluid 血液和组织液之间的物质交换 A. Diffusion: the most important way. 扩散:最重要的方式
Lipid soluble substances: O2, CO2 non-lipid soluble substances 非脂溶性物质 Rate of diffusion =(DA/a)(Co-Ci) D: diffusion coefficient D:扩散系数
Filtration and reabsorption play an important role B. Filtration and reabsorption 滤过和重吸收 Filtration and reabsorption play an important role in the generation of interstitial fluid. 在组织液的生成中起重要作用。 C. Pinocytosis 吞饮 The big molecules can carry out the exchange of substances through Pinocytosis. 大的分子可以通过这种方式进行物质交换。
Formation of interstitial fluid 组织液的形成 About 60% of the weight of the health adult is water, in which: 正常人体重中大约60%是水,其中 细胞内液 (5/8) 1/5: 血浆 细胞外液 (3/8) 4/5: 组织液和腔室内液体
A端 ΔPf=(30+15)-(25+10)= +10mmHg V端 ΔPf=(12+15)-(25+10)= - 8 mmHg
Formation of interstitial fluid 组织液的生成 EP= ( Pc +if ) – (p + Pif ) 有效滤过压=(毛细血管血压+组织液胶渗压)- (血浆胶体渗透压+组织液静水压) Pc :毛细血管血压 if :组织液胶体渗透压 p :血浆胶体渗透压 Pif :组织液静水压
The filtration and reabsorption of fluid through the capillary wall is determined by the difference of the strength of filtration and reabsorption. 液体通过毛细血管壁的滤过和重吸收取决于有效 滤过压的大小,即滤过的力量和重吸收的力量之差。 促使滤过: Pc , if 促使重吸收: p ,Pif
The fluid volume filtrating through capillary wall per unit time equals the corss product of effective filtration pressure and Kf. 单位时间内通过毛细血管壁滤过的液体量等于 有效滤过压与滤过系数Kf的乘积。 V = Kf [ ( Pc +if ) – (p + Pif ) ] V:单位时间内通过毛细血管壁滤过的液体量 Kf:滤过系数
2. Factors affecting the formation of interstitial fluid 影响组织液形成的因素 The above-mentioned factors which determines the EP all play a role in the maintenance of the dynamic balance of the formation and reabsorption of the interstitial fluid. 上述决定有效滤过压的各种因素,都参与维持 组织液的生成和重吸收的动态平衡。
毛细血管血压升高↑ 血浆胶体渗透压降低↓ oedema 水肿 淋巴回流受阻 毛细血管壁通透性↑
VII.Formation and return of lymph 淋巴液的生成和回流 About 120ml lymph fluid enters into blood circulation for an health adult in resting state, in which 正常成人安静状态下大约每小时有120ml淋巴液进入 血液循环,其中 100ml 胸导管 进入血液 20ml 右淋巴导管
physiological function 生理功能 1、Reclaiming protein and absorbing nourishment 回收蛋白质、吸收营养物质 2、Cleaning the RBC、bacterium and foreign substance 清除组织中红细胞、细菌、异物 3、Balancing the formation and absorption of interstitial fluid 平衡组织液的生成和吸收
人在罹患丝虫病时虫体有时可以堵塞身体的部分淋巴管道。淋巴回流障碍导致局部组织液积聚而形成膨胀隆起。
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