7.心的血供PPT参考课件.ppt

单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,*,Blood Supplies of the Heart,Max Song,1,Provide oxygen for body cells,Transport nutrients for body,Transportation of metabolic wastes,Importance of blood supply,2,The four-chambered heart is a dynamic organ.,It works day and night to propel blood flowing,throughout of the body.,Just like other organs of the body,the heart,uses oxygen and nutrients derived from blood,when it pumps.Therefore,it needs a,continuous blood supply.,Blood flowing through coronary arteries,accounts for,45%,of cardiac output.One,hundred grams of myocardial tissue uses,8-10 ml oxygen,from blood every minutes.,The heart absorbs,70-75%,of oxygen of,blood when it flows through the heart.,So,absorption rate of oxygen of the heart is,highest.,The brain has a high metabolic rate that reflects the energy,requirements of constant neural activity.It receives about,15%,of the cardiac output and utilizes,25%,of the total,oxygen consumption of the body.,The need of the heart to blood supply,3,Although the heart is filled with,blood,however,this contained,blood provides little nourishment,to the heart walls,which are too,thick to obtain much nutrition by,diffusion alone.Instead,the heart,derives its rich blood supply from,two small vessels,the right and,left coronary arteries,.,Myocardial cells are very sensitive to,anoxia,.Insufficient,blood supply to the heart would result in,angina pectoris,even more serious consequence,cardiac infarction,.,Millions of people die every year from coronary disease.,For medical students,knowledge about blood supply of,the heart and distribution of coronary artery branches,therefore,are of the utmost clinical and practical,importance.,4,Origin of blood supplying the heart,Blood contained within the heart chambers,Arteries outside of the heart,Right and left coronary arteries,5,A.Blood contained within the heart chambers,The endocardium and some subendocardial tissues located,immediately external to the endocardium receive oxygen and,nutrients by diffusion or microvasculature directly from the,chambers of the heart.,6,B.Arteries outside of the heart,Branches of the internal thoracic arteries,Bronchial arteries,Pericardiacophrenic arteries,7,The right and left coronary,arteries,the first branches,of the aorta,carry blood to,supply most of the,myocardium.And then,the,cadiac venous blood is,drained to the right atrium.,This circuit of blood,circulation is called the,coronary circulation,the,so-called “,third circulation,”,which is one special part of,systemic circulation,C.Right and left coronary arteries,8,Origin of the,coronary arteries,9,Main course,of coronary,arteries,10,11,Parietal Coronary Artery&Myocardial Bridges,12,Left coronary a.,1.Anterior interventricular a.,13,Types of anterior interventricular branch,14,前室间支的分支,左室前支,左圆锥支,右室前支,前室间隔支,15,2.,旋支,左室前支（斜角支）,2.,左房前支,16,3.,左缘支,4.,左房后支,17,右冠状动脉,(Right coronary a.),1.,窦房结支,2.,右圆锥支,3.,右室前支,4.,右缘支,5.,右房支,18,6.,右室后支,7.,左室后支,8.,房室结支,9.,后室间支,19,10.,房间隔前动脉（耳大吻合动脉）,(Kugel artery),20,房间隔前动脉（耳大吻合动脉）,(Kugel artery),21,房间隔前动脉,（耳大吻合动脉）,(Kugel artery),22,冠状动脉的分布类型,(Dominance of the coronary arteries),Dominance of the,coronary arterial,system is defined,by which artery,gives rise to the,posterior,interventricular,artery.,Dominance of the,right coronary,artery is typical,with the right,coronary artery supplying,most of the diaphragmatic,surface.The left coronary,artery is dominant in,approximately 10%of,people,and there is,codominance in 15%of,people.,23,冠状动脉分支,在心室壁内的,分支类型,24,在心肌层内，微动脉（直径,0.3mm,）与肌束平行，然后,发出分支穿过肌束膜再分成毛细血管包绕每一条心肌纤维。,婴儿时期每,4,6,条心肌纤维约有一条毛细血管包绕，在成,人平均每一条心肌纤维有一条毛细血管包绕。,心肌肥大时，心肌纤维和毛细血管数的绝对值均增加，二,者的比例并无改变。肥大心肌缺氧，主要原因并非是由于,心肌纤维增粗导致毛细血管向心肌纤维内部氧的弥散困难，,而是由于冠状动脉管径与增粗的心肌纤维本身相比相对变,小,，因此导致整个心的供血不足而致心肌缺氧。,25,心局部的血液供应,室间隔,乳头肌,心传导系,A,窦房结,B,房室结,C,房室束及左、右束支,26,室间隔的血液供应,27,乳头肌的血液供应,乳头肌分为三型,:,指状型,、,结合型,、,中间型,。,乳头肌的动脉由冠状动脉的分支在心外膜下分出，并穿过,心肌层，是冠状动脉的终末支，行程较长。,28,指状型乳头肌,通常从其基,底接受一大的中央动脉，,此动脉起于该处心外膜,下的冠状动脉动脉分支，,是一个长的终末支，沿,乳头肌纵轴从根部穿肌,层走向乳头肌的顶端，,经过,45,次分支，并互,相吻合形成网状，以供,应整个乳头肌，但与乳,头肌以外的心内膜下血,管丛之间很少有或没有,吻合。因此,营养指状型,乳头肌的血管一旦发生,梗阻，将导致整个指状,型乳头肌的缺血坏死,。,29,结合型乳头肌,的动脉与乳头肌纵轴垂直，且有几条动脉分,节段型地进入乳头肌，这些血管的分支不仅彼此互相吻,合，而且与乳头肌以外的心内膜下血管丛相连接。,中间型乳头肌,的血管配,布为混合型，即上述,两型配布皆有。,营养这两类乳头肌的血,管由于和心内膜下的,血管之间有吻合，所,以即使发生梗阻，这,两类乳头肌也可以从,心内膜下的血管获得,营养,，这有助于保持,乳头肌结构和功能的,完整性。,30,前外侧组乳头肌,由左冠状动脉的,前室间支,及,旋支,分支供血。,后内侧组乳头肌,通常由右冠状动脉的,左室后支,及左冠状动脉的,旋支,供血，,少数亦可来自前室间支绕至心脏下面的终末支供血。,由于两个乳头肌恒定地由多个来源动脉供血，因此单一的一个大的冠,状动脉支的梗阻，很少使乳头肌的血供完全阻断。临床上乳头肌断裂常,常是由于一个以上动脉支梗阻所致。,1.,左心室乳头肌的血供,31,前组乳头肌,血供来自前降支的,室间隔支,、,右室前支,或右,冠状动脉的,右缘支,。在乳头肌内均为纵行分布。,后组乳头肌,和,隔侧组乳头肌,则由附近的动脉分支供血。,2.,右心室乳头肌的血供,32,心传导系的血供,冠状动脉分支栓塞或损,伤时，可引起相应部位,的心肌缺血或坏死，同,时也会产生心传导系的,供血障碍，导致心律失,常。,33,窦房结的血供,(Blood supply of SA node),窦房结由冠状动脉的,窦房结动脉,供血。,该动脉在国人约,66.76,起于右冠状动脉，,31.9,起于左冠状动脉，,另有,1.34,的人窦房结动脉有两支，分别起于左、右冠状动脉。,34,是右冠状动脉第一个,分支。,此动脉起始后，在主,动脉和右心耳之间，,右房内侧壁向后上行，,至上腔静脉根部，多,以逆时针方向从后方,绕上腔静脉口，形成,一个围绕上腔静脉的,动脉环，故该动脉有,时亦称为,上腔静脉口,支,。该动脉从窦房结,尾端穿经窦房结的中,央，此时改称为,窦房,结中央动脉,。,少数以顺时针方向从,窦房结的头端入窦房,结。,起于,右冠状动脉,的窦房结动脉,(Sinoatrial artery originated from,the right coronary artery),35,起于,左冠状动脉,的窦房结动脉,(Sinoatrial artery originated from,the left coronary artery),多起于左冠状动脉的旋支，在升主动脉后方横过左心房前面至上腔静脉,根部，或绕经左心房后面至上腔静脉根部，然后从窦房结后端穿经窦房,结，营养窦房结。,36,37,窦房结动脉的解剖学特点,1.,其起点接近冠状动脉口；,2.,沿途分支供应心房肌和房间隔的,大部分，并与其它心房支形成许,多吻合；,3.,穿经窦房结并完全被窦房结组织,包裹；,4.,穿经窦房结时管径变化不大。,窦房结供血不足可以产生窦性,心动过缓、窦性停搏或心房颤,动等各种房性心律失常。近年,来将这些由窦房结缺血引起的,临床症状，统称为,病态窦房结,综合征,。,无论是起于右冠状动脉还是起,于左冠状动脉的窦房结动脉，,它们在进入窦房结之前，都和其它心房支形成许多吻合。,由于窦房结动脉的起点和行径常有变化，且窦房结供血不,足又常常引起房性心律失常，因此在心脏手术切开心房时，,应尽量避免损伤窦房结动脉。,38,2.,房室结的血供,(Blood supply of the AV node),1.,房室结动脉,2.,房间隔前动脉,(Kugel artery),3.,左房后支,39,1.,房室结动脉,绝大多数起始于右冠状动脉。少数从左冠状动脉旋支发出，左右冠状动脉各,发一支者极为少见。房室结动脉起始于右冠状动脉或是左冠状动脉，取决于,后室间支从哪条动脉发出。,房室结动脉起始处的右或左冠状动脉多呈,U,型弯曲，房室结动脉由此弯曲的,顶点发出，然后向前上至深部到达房室结和房室束。,40,41,2.,房间隔前动脉,(Kugel artery),起于右冠状动脉或或左冠状动脉起始部分，自房间隔向后下，至房室结。,42,3.,左房后动脉,常起于旋支，由冠状窦口的前方进入房室交界区,43,房室结动脉，房间隔前动脉,(Kugel artery),和左房后支三条动脉之间互相,吻合，营养房室结区（包括房室结和房室束）。三条动脉有互相消长的,关系，即一条动脉粗大，其它动脉则细小。,由于房室结区这种多支多源的血液供应特点，故房室结动脉栓塞只会出,现房室结区的暂时性血供障碍，所导致的房室传导阻滞也是暂时性的。,房室结血液供应的特点,44,房室结可分为浅层和深层。,尚有部分深层的房室结细,胞位于中心纤维体内，形,成结细胞岛。,房室结内有多条房室结动,脉，但不形成中央动脉。,1.,心内膜,2.,房室结浅部,3.,房室结深部,4.,中心纤维体,5.,室间隔肌部,房室结动脉,房室结动脉,45,3.,房室束及左、右束支的血供,房室束和左、右束支的起始部，主要由,房室结动脉,和左冠状动脉前室间支的,室间隔支,供血。,46,左束支主干前半部、左束支的前组和间隔支、后组分支的前半均由左冠状动脉,前室间支的室间隔支,供血；左束支主干的后半部和左束支后组的后半部则由右,冠状动脉发出的,房室结动脉,和,后室间支的室间隔支,供应。,由于左束支的前组仅由前室间隔支供血，故左冠状动脉的前室间支栓塞时，易,引起左束,支前组阻,滞。左束,支的后组,由于是双,重供血，,故左束支,的后组的,传导阻滞,比较少见。,47,右束支的,上段,位于室间隔的上,1,3,，主要由,房室结动脉,和前室间支的,室间隔支,供血；,中段,位于圆锥乳头肌的后方，仅由前室间支的,前室间隔支,供血；,下段,行,于隔缘肉柱内，由,前室间隔支,和,右室前支,供应。,由于右束支主要由前室间隔支供应，故左冠状动脉的前室间支梗塞可引起右束,支传导阻滞，并多为永久性阻滞。,48,49,心传导系各部位均有特定的血液供应。即：,窦房结,主要由窦房结动脉供血；,房室结,及,房室束,主要由房室结动脉供血；,左,、,右束支,则主要由前、后室间动脉的室间隔支供血。,窦房结动脉和房室结动脉栓塞造成窦房结和房室结缺血是暂时,性的，其功能可逐渐恢复。其原因主要是由于窦房结动脉与心,房动脉分支间有丰富的吻合，而房室结区则由多条动脉供血。,右冠状动脉除营养两个结,(,房室结动脉,92,、窦房结动脉,66.76,起于右冠状动脉,),，还供给心下壁,(,即膈面,),大部分的血液，因此,心下壁的急性梗塞比其它任何部位的梗塞都危险。如果右冠状,动脉特别是在其,起始段,(,窦房结动脉起始以前,),发生急性阻塞，,则对传导系统的功能将有严重影响。因此，从这个角度上讲，,也有人把右冠状动脉称为“,猝死动脉,”。,小结,50,由于右束支是一个单一的束，左束支起始呈片状，并分为,前、后两支或前、隔、后三支，因此，,右束支比左束支更,易受到由血管栓塞所引起的损伤,。,下壁,心肌梗塞多发生房室传导阻滞，但常为暂时性的。这,是由于累及了房室结、房室束和束支的起始部分，,一般为,暂时性的缺血所致，很少引起病理形态的改变,。同时，由,于这些结构均有多个来源的血管供应，某一血管阻塞了，,另一血管尚有一定的代偿作用。,前壁,梗塞多发生束支传导阻滞，这是由于累及了左束支,(,部分,),或右束支，因其系单一来源的血管供血，一旦该来,源血管的主干阻塞，即易发生坏死性病变，,故前壁梗塞引,起的束支传导阻滞多为永久性的,。,51,The coronary arteries are readily subject to damage,especially,occlusion because of coronary atherosclerosis,and therefore,it is important to consider the collateral circulation,both,cardiac,and,extracardiac anastomoses,.,The branches of coronary arteries are considered to be end,arteries,ones that supply regions of the myocardium without,overlap or anastomoses from other large branches.,However,anastomoses do exist between branches of the coronary arteries,subepicardial or myocardial,and between these cardiac arteries,and extracardiac vessels such as internal thoracic vessels,.,Clinical studies show that,anastomoses,cannot,provide collateral,routes quickly enough to prevent the effects of sudden coronary,artery occlusion.,The functional value of these anastomoses,appears to be more effective in slowly progressive coronary,artery disease.,Collateral Circulation of the Heart,（心的侧副循环）,52,The right and left coronary arteries meet on the surface,but clinically there is a very poor anastomosis between,these two arteries,and this is probably because the,blood flow is occluded or even reversed in the coronary,arteries in ventricular systole.,In the myocardium there are very rich anastomoses,between the right and left coronary arteries,but the,vessels taking part are small.These anastomoses are,genetically determined and it has been shown that they,can enlarge if the occlusion of one vessel is gradual.,If,however,there is sudden occlusion there is no time,for these vessels to enlarge and there is death of a,segment of cardiac muscle.,53,心的血管吻合,1.,冠状动脉间的侧副吻合,2.,心外的侧副吻合,A,升主动脉壁动脉网,B,心房动脉网,C,心包动脉网,54,1.,冠状动脉间的侧副吻合,右冠状动脉的右圆锥支与,左冠状动脉的前室间支,房室结区,窦房结动脉与,心房的动脉,55,A.,升主动脉壁动脉网,2.,心外的侧副吻合,56,B.,心房动脉网,57,C.,心包动脉网,58,冠状动脉吻合管的直径和长度随年龄增长而增加，至,18,20,岁时,达正常大小。正常人吻合管直径一般大于,100,m,。,一般认为人的冠状动脉如发生栓塞，发展具有保护性的侧副循环,比实验动物需要数倍的时间。有证据表明，虽然在急性冠状动脉,栓塞后几天就能见到较大的血管吻合，但要使这些吻合丰富起来，,却需要几个星期，如要它们充分发挥作用，甚至需要几个月时间。,吻合的存在并不能说明就有侧副循环的功能，关键是哪些因素影,响吻合形成有效的侧副循环。影响,吻合形成有效的侧副循环,因素,包括：动脉栓塞发展的速度、栓塞的部位、过去有无血管栓塞史,以及病人的年龄等。青年人侧副循环还未很好的发育，一旦主要,血管栓塞易发生心肌梗塞。随着年龄的增长和局部缺血的影响，,吻合血管的数目增多，管径变粗，如仅一条动脉栓塞则不易发生,心肌梗塞。,59,冠状动脉侧副循环的建立及影响因素,冠状动脉侧支循环的建立是一个长期的过程,冠状动脉侧支循环的血流量有限,冠状动脉侧支循环的建立对于梗塞区心肌的,形态和功能具有一定程度的改善,梗塞区近侧和远侧血管床之间的压力差,缺氧,贫血,运动,血管扩张剂,60,Atherosclerosis,61,诊断：冠状动脉造影,62,诊断：冠状动脉造影,63,A triple coronary bypass surgery.,Several vessels may be used in the,autotransplant,including the,internal thoracic artery and the,greater saphenous vein.,治疗：搭桥术,64,治疗：支架置入,65,冠状动脉三维重建,66,心的静脉,(veins of heart),Tributaries:,Great cardiac v.,Middle cardiac v.,Small cardiac v.,1.,冠状窦,(Coronary,sinus),67,68,2.,心前静脉,(Anterior Cardiac v.),69,3.,心最小静脉,(Smallest Cardiac vv.),70,心的静脉三维重建,71,