医学ppt课件器官循环

SECTION 5 ORGAN CIRCULATION 第五节 器官循环,The blood flow of organ denpends on 器官的血流量取决于： The difference between aortic pressure and central venous pressure 主动脉压与中心静脉压之差 The diastolic and systolic state of blood vessel in this organ 该器官阻力血管的舒缩状态,I. Coronary Circulation 冠脉循环 II. Pulmonary Circulation 肺循环 III. Cerebral Circulation 脑循环,I . Coronary Circulation 冠脉循环,左冠状动脉 右冠状动脉 供血区域 左心室前部 左心室后部 和左侧部 和右心室 回流途径 冠状窦 心前静脉 右心房 右心房,Anatomic consideration 解剖特点, The boles and branches of left and right coronary artery often penetrate myocardium in direction perpendicular to cardiac surface. 左右冠状动脉主干分支垂直于心脏表面的方向 穿入心肌 。 Myocardial capillary distribution is extremely abundance . 心肌的毛细血管网分布极为丰富 。 Collateral coincidence between coronary is less . 冠脉动脉之间的侧支吻合少 。,2. Physiological characteristic of coronary circulation 冠脉循环的生理特点, The pathway is short and blood flow is fast 途径短，血流快, Blood pressure is high 血压较高, Blood flow is big and it is 4%5% of cardiac output 血流量大,心输出量的4%5%, Arteriovenous oxygen difference is great during silence period 平静时动-静脉血含氧量差很大, Blood flow fluctuates with cardiac cycle 血流量随心动周期波动,Isovolumic contraction phase rapid ejection phase reduced ejection phase diastolic phase (isovolumic relaxation phase) 等容收缩期快速射血期 减慢射血期 舒张期（等容舒张期）,Level of arterial diastolic pressure and size of diastolic phase are important factors of determining coronary flow . 动脉舒张压高低和舒张期长短是决定冠脉血流量 的重要因素。 Contraction and relaxation impact on right ventricle is not so obvious as to left ventricle. 收缩及舒张对右心室的影响不及对左心室明显。,3. Regulation of coronary blood flow. 冠脉血流量的调节 Normal value: 60-80ml/100g.min. 静息血流量为6080ml/100g.min Exercise 300-400ml/100g.min 运动时血流量为300400ml/100g.min O2 consumption 7-9ml/100g.min. O2 extraction 65-70% 氧耗量为79ml/100g.min，占氧输出量的6570%。,(1) Regulation of metaboilic level of myocardium to coronary flow 心肌代谢水平对冠脉血流量的调节 Metaboilic level of myocardium is an important factor . 心肌本身的代谢水平是最重要因素。, The energy for myocardial contraction nearly all comes from aerobic metabolism. 心肌收缩的能量几乎完全来自有氧代谢。, Consumed oxygen of myocardium is large, oxygen intake much, oxygen uptake potency low. So the demand of myocardium to oxygen increase mainly depends on coronary distension. 心肌耗氧量大，摄氧多，摄氧潜力低。故心肌对氧需求增加主要依赖冠脉扩张。 Myocardium regional metabolic product is the main factor which causes coronary dilation and the function of adenosine is the most important. H+,CO2, ethylidene lactic acid 、BK、PGE also can dilate coronary. 心肌局部代谢产物是导致冠脉扩张的主要因素，其中腺苷作用最为重要。H+、CO2、 乳酸、BK、PGE等亦可舒张冠脉。,Occupy the secondary position 居次要地位 Coronary accepts the domination of cranial nerve and adrenergic nerve . 冠脉接受迷走神经及交感神经支配。 vagus nerve : direct action is to dilate coronary 迷走神经：直接作用是使冠脉舒张,(2) Neural regulation 神经调节,sympathetic nerve : receptor excitation coronary contraction (direct) 交感神经：受体兴奋冠脉收缩（直接） receptor excitation coronary dilatation (indirectdirect) 受体兴奋冠脉舒张（间接直接）,3. Hormone regulation 激素调节 NE, EP, thyroxin，ADM coronary dilation 去甲肾上腺素、肾上腺素、甲状腺素、 肾上腺髓质素 冠脉舒张 ADM:来源于VEC和VSMC的血管活性物质（52肽）。 Angiotensin, vasopression coronary constriction 血管紧张素、血管加压素冠脉收缩,Adrenomedullin 肾上腺髓质素（ADM),One new biologically active peptide found in 1993 by Kitamura . 1993年Kitamura分离出的一种新的生物活性肽。 ADM has an evident expansion effect on the main arteries、coronary artery 、resistance vessel. ADM对大动脉、冠状动脉、周围阻力血管均有明显 的扩张作用。,Coronary heart disease 冠心病 Coronary heart disease results from coronary atherosclerotic ,which leads to ischemic and anoxyaemia of cardiac muscle.It is also called ischemic heart disease. 因冠状动脉粥样硬化使血管腔阻塞导致心肌缺血 缺氧而引起的心脏病。亦称缺血性心脏病。,Pathogenesy 发病机制 The atherosclerotic plaque can cause a local thrombus . The thrombus usually occurs where the plaque has broken through the endothelium ,thus coming in direct contact with the flowing blood .The blood platelets begin to adhere to the plaque, fibrin begins to be deposited, and red blood cells become entrapped to form a blood clot that grows until it occludes the vessel .,动脉粥样硬化斑块可以引发局部血栓。血栓通常发生于斑块已经侵入内皮处，血流的直接冲击使血液中的血小板粘附到斑块之上，血浆纤维蛋白发生降解，红细胞叠连形成血栓。血栓可不断增大直至堵塞血管，从而诱发心肌缺血缺氧的一系列病理性改变。,The occurrence of coronary disease is closely relates to the degree of sclerostenosis and branches. 本病的发生与冠状动脉粥样硬化狭窄的程度和支数 有密切关系。 Occurs most at: the upper and middle part of anterior descending branch、the middle 1/3 part of right coronary artery. 好发部位：前降支上、中1/3，右冠状动脉中1/3。,II Pulmonary Circulation 肺循环,Pulmonary circulation is the blood circulation that venous blood ejected from right ventricle through alveolar Wall ,carrying on gas exchange with alveolar air, turning into arterial blood, returning to left atrium。 肺循环特指右心室射出的静脉血通过肺泡壁与肺泡 气进行气体交换变成动脉血后返回左心房的血液循环。,1. Physiological characteristic of pulmonary circulation 肺循环的生理特点,(1) Short circulatory pathway and small peripheral resistance. 循环途径短，外周阻力小。 (2) Blood pressure is low and it is only 1/61/5 of systemic circulation . 血压较低，仅为体循环的1/61/5。 肺循环毛细血管平均压：7mmHg,Interstitial fluid in lung is negative pressure .The alveolar membrane and capillary wall tightly sticks to each other. It is favorable to gas exchange between alveoli of lung and blood. 肺部组织液为负压，肺泡膜和毛细血管壁紧密相贴， 利于肺泡和血液之间的气体交换。 Left heart failure Edema of lung 左心衰竭 肺水肿,(3) Pneumoangiogram compliance is big , blood volume change of lung is great. 肺血管顺应性大，肺的血容量变化大。 Silence period 平静时：450ml（全身血量的9） Forced expiration 用力呼气：200ml Deep inspiration 深吸气：1000ml Function: “ blood reservoir ” , compensate the deficit of systemic blood volume during blood loss. 作用：“贮血库”，失血时代偿体循环血容量的不足。,The fluid exchange ofcapillaries of pulmonary circulation 肺循环毛细血管处的液体交换,Intrapleural negative pressure：reabsorb filtration fluid to keep pulmonary alveoli dry ,thus prompts the process of gas change. 胸膜腔负压：重吸收滤过液，保持肺泡干燥，利于 气体交换。 平静呼气末：5mmHg 3mmHg left heart failure、mitral stenosis：pneumonedema 左心衰、二尖瓣狭窄：肺水肿,Respiratory wave of arterial blood pressure 动脉血压的呼吸波 Blood volume of pulmonary circulation is influenced by breathing cycle. 肺循环的血容量受呼吸周期的影响。 The start of inspiration: blood pressure descends. 吸气开始：动脉血压下降 Latter half period of inspiratory phase :descents to minimum ,then begin to go up. 吸气相的后半期：降至最低点，并开始回升。 Expiratory phase : peak value 呼气相的后半期：最高点,2. Regulation of Pulmonary flow 肺循环血流量的调节 (1) Neural regulation 神经调节 In general , systemic circulation contracts and lung blood volume increases when sympathetic nerve excites. Stimulating vagus nerve can cause vasodilatation and pulmonary vascular resistance increases. 整体情况下，交感神经兴奋时体循环收缩肺血容量 增加。刺激迷走神经则引起轻度舒血管作用，肺血 管阻力稍有降低。,(2) Oxygen partial pressure of alveolar air 肺泡气的氧分压 Both acute or chronic hypoxia can cause vasoconstriction and vasoconstriction increase . 急性或慢性的低氧都能使肺血管收缩，血流阻力增大。 Significance: hypoxic perialveolar arteriole contracts, more blood flows through sufficient ventilation alveolar and carries on effective gas exchange. 意义：氧分压低的肺泡周围微动脉收缩，较多的血液流经通气充足的肺泡进行有效的气体交换。,(3) Impact on pneumoangiogram of vasoactivesubstance 血管活性物质对肺血管的影响 Contract arteriole : adnephrin ,noradrenaline , Angiotensin II, thromboxane A2, prostaglandin F2 收缩微动脉：肾上腺素、去甲肾上腺素、 血管紧张素II 、血栓素A2，前列腺素F2 Relax arteriole : histamine , 5-HT 舒张微动脉：组胺、5羟色胺,III Cerebral Circulation 脑循环,blood supply of cerebral circulation 脑循环血液供应 Frontal 2/3 part of cerebral hemisphere: internal carotid 大脑半球前2/3脑区：颈内动脉 Post 1/3 part of cerebral hemisphere, cerebellum and brain stem: cone artery 大脑半球的后1/3脑区，小脑，脑干：椎动脉,脑静脉颈内静脉腔静脉 vena encephali internal jugular vein vena cava Function：Providing brain with oxygen, energy while discarding its metabolic products to maintain homeostasis . 功能：为脑组织供氧、供能、排出代谢产物以维持 内环境稳定。,1. Characteristic of cerebral circulation 脑循环的特点,(1) Plentiful cerebral blood flow and oxygen consumption 脑血流量大，耗氧量多 The weight of brain is about 20 percent of body weight and its blood flow is 15 percent of cardiac output，oxygen consumption is about 20 percent of whole body oxygen consumption. 脑的重量约占体重的20，血流量占心输出量的15。耗氧量约占全身耗氧量的20。,2. Little change of cerebral blood flow 脑血流量变化小 Brain tissue cant compress in bony cranial cavity. 骨性颅腔，脑组织不可压缩。 3. Great influence of regional chemical circumstance on systaltic activity of cerebral vessels 局部化学环境对脑血管舒缩活动影响大 Oxygen and carbon dioxide partial pressure have obvious influence on cerebral blood flow . 血液中CO2和O2分压对脑血流量影响明显。,4. Little function of neural factor to cerebral vascular activity 神经因素对脑血管活动的调节作用小 5. Blood brain barrier existing in cerebral circulation 脑循环中存在血脑屏障,2. Regulation of cerebral blood flow 脑血流量的调节,（1）Autoregulation of cerebral vascular 脑血管的自身调节 Cerebral blood flow mainly depends on pressure difference between cerebral artery and cerebral vein and resistance of blood flow of cerebral vessels . The BP of arteria carotis is the main factor of influencing cerebral blood flow. 脑的血流量主要取决于脑的动脉和静脉的压力差和 脑血管的血流阻力。 影响脑血流量的主要因素是颈动脉压。,When MAP changes within 60 140mmHg, the cerebral vessels can keep the cerebral blood flow at a constant level through autoregulation. 当MAP在60 140mmHg之内变动时，脑血管可通过 自身调节机制使脑血流量保持恒定。,2. Impact of Oxygen and carbon dioxide partial pressure on cerebral blood flow CO2和O2分压对脑血流量的影响 PCO2H2CO3H+cerebral vascular diastoles cerebral blood flow H+ homeostasis recovers 乳酸，丙酮酸，酸性代谢产物 PCO2 H2CO3 H+脑血管舒张 脑血流量增多 H+ 恢复内环境稳态,hypoxia Po2 cerebral vessel relaxing brain blood flow O2 supply 缺氧氧分压 脑血管舒张 脑血流量 氧供应 Function: avoiding decrease of neuron activity and any damage to brain in local regulation of brain blood flow. 作用： 在脑血流量的局部调节中防止神经元活性 下降和防止脑功能损害的保护性反应。,(3) The effect of cerebral Metabolism to brain blood flow 脑的代谢对脑血流的影响 Mechanism: cerebral vessels relax due to metabolic product of H+、K+、adenosine, PO2. 机制：通过代谢产物如H+、K+、腺苷、PO2 降低 引发脑血管舒张。,4. Neural regulation 神经调节 Neural factors do little to regulate vasomotion. when doing violent sports, the sympathetic excitation leads to increase in BP, and large artery and medium-sized artery constrict to prevent high pressure in little vessels, which may cause apoplexy. 神经因素在脑血管活动调节中所起的作用很小。激烈运动时，交感神经兴奋血压显著升高，脑大动脉和中动脉收缩，防止高压传递至脑部小血管致使脑出血。,3. Blood-cerebrospinal fluid barrier and blood-brainbarrier 血-脑脊液屏障和血-脑屏障,（1）Blood-cerebrospinal fluid barrier 血-脑脊液屏障 (2) Blood-brain barrier 血脑屏障,（1）Blood-cerebrospinal fluid barrier 血-脑脊液屏障,A special barrier existing between blood and CSF is called blood cerebrospinal fluid barrier. 在血液和脑脊液之间存在一种特殊屏障，称为血 脑脊液屏障。