blood-brainbarrier血－脑屏障.ppt

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： ⒈ The difference between aortic pressure and central venous pressure 主动脉压与中心静脉压之差 ⒉ 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 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60～80ml/100g.min Exercise 300-400ml/100g.min 运动时血流量为300～400ml/100g.min O2 consumption 7-9ml/100g.min. O2 extraction 65-70% 氧耗量为7～9ml/100g.min，占氧输出量的65～70%。 ② 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。 ③ 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。 sympathetic nerv