第五节 特殊器官循环2017幻灯片.pptx

CHAPTER 4 CIRCULATION 血 液 循 环; SECTION 5  ORGAN CIRCULATION 第五节 器官循环; 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 和右心室 回流途径 冠状窦→ 心前静脉→ 右心房 右心房 ;7;① 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 。 ② Myocardial capillary distribution is extremely abundant .The proportion of capillary and myocardial fiber is 1:1. 心肌的毛细血管网分布极为丰富 ,毛细血管数和心肌纤维数的比例为1:1。 ③ Collateral coincidence between coronary is less . 冠脉动脉之间的侧支吻合少 。; 2. Physiological characteristics of coronarycirculation 冠脉循环的生理特点;Blood flow fluctuates with cardiac cycle 血流量随心动周期 波动 ; Level of arterial diastolic pressure and size of diastolic phase are important factors in determiningcoronary 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 do not have such great impact on blood flow of right ventricle as that of left ventricle. 收缩及舒张对右心室血流的影响不及对左心室明显。 ;3. Measurement of coronary blood flow 冠脉血流量的测量; 4. 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 ; ; ② Large oxygen consumption of myocardium , much oxygen intake, low oxygen intake potency. So myocardial demand upon increasing oxygen mainly depends on coronary dilation. 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 Local metabolic product of m