Chapter 26 Development of cardiovascular system

Ⅰ. Establishment of the primitive cardiovascular system Blood island Primitive blood vessels Hemopoietic stem cells Extraembryonic capillary networks Intraembryonic capillary networks

capillary networks fuse or disappear to form primitive cardiovascular system

Primitive cardiovascular system a pair of heart tubes a pair of ventral aortae a pair of dorsal aortae the first pair of aortic arches Vitelline arteries Vitelline veins Sinus venosus allantoic( umbilical) A allantoic ( umbilical) V

Aortic sac intersegmental artery anterior cardinal veins posterior cardinal veins common cardinal veins 2nd~6th pairs of aortic arches

vitelline circulation allantoic(umbilical ) circulation embryonic circulation

组 成 20天 4周初 4周末 心 管 原始心脏 心管：1对  并成1条  原始心脏 动脉 静脉

20天 4周初 4周末 背主A 弓A 脐A 卵黄A 心管 动脉： 静脉 1对背主A  并成1条，许多分支 数对卵黄A 1对脐A 6对弓A

心管 动脉： 静脉 1对卵黄V 1对脐V 1对前主V 1对后主V 总主V，开口于心管尾端的V窦 20天 4周初 4周末 前主V 后主V 脐V

Ⅱ.Development of the heart 1. Development of the Cardiac tube Cardiogenic area Cardiogenic plate (cord) Pericardiac coelom Cardiac tube

生心区 （ Cardiogenic area）： 口咽膜前方的中胚层

生心区出现的空腔－围心腔 pericardiac coelom 其腹侧出现的1对细胞索－－－－生心板cardiaogenic plate 口咽膜 生心板 生心区出现的空腔－围心腔 pericardiac coelom 其腹侧出现的1对细胞索－－－－生心板cardiaogenic plate

围心腔 心 管 板中央变空－ 心 管 cardiac tube

心 管 围心腔 胚体头端向腹侧卷曲－－围心腔, 心管旋转180°

心 管 围心腔 心管融合成 1 条，陷入围心腔内

---lateral folds of the embryo make the two cardiac tube approach and fuse with each other

心背系膜 dorsal mesocardium: cardiac tube invaginate into pericardiac coelom and connect to it by dorsal mesocardium

心包横窦 Pericardial sinus Myoepicardial mantle myocardium epicardium cardiac jelly Subendothelium subendocardium 心包横窦 心肌膜 心胶貭 heart wall: endocardium ，myocardium and epicardium

围心腔 心 管 横 窦 心管头端 A，心管尾端 V

2. Establishment of the external appearance of the heart 心脏外形的演变 动脉端 心 管 静脉端

心室 Primitive ventircle 心房 Primitive atrium 出现三个膨大 three dilatations 心球 bulbus cordis 心室 Primitive ventircle 心房 Primitive atrium 心 球 心 室 心 房

bulboventricular loop 静脉窦 sinus venosus 动脉干 truncus arteriosus 心管扭曲成“U”型 球室袢 bulboventricular loop 动脉干 心 球 心 室 心 房 静脉窦

进一步扭曲成“S”型 动脉干 球室袢 静脉窦

atrioventricular canal 心 房 弓动脉 心 室 atrioventricular canal 心脏初具成体心脏外形!!!

3. Formation of the cardiac septa (1)房室管的分隔 Separation of the atrioventricular canal 心内膜垫 endocardiac cushion Left atrioventricular canal Right atrioventricular canal

Separation of the atrioventricular canal 心内膜垫 腹、背心内膜垫融合 左房室孔 右房室孔

二尖瓣 三尖瓣 心内膜垫 左右房室孔间充质增生 左 右 Mitral valves Tricuspid valves

(2) 心房的分隔 Separation of the atrium 心房顶壁出现半月形隔——原发隔 Septum primum 心内膜垫与原发隔之间——原发孔 Foramen primum 第1房间隔 第1房间孔 心内膜垫

Separation of the atrium 小穿孔 第1房间孔 心内膜垫

Separation of the atrium 第2房间隔 小穿孔融合成大孔——继发孔 Foramen secundum 原发孔闭合 心房顶壁又出现新月形隔---继发隔 Septum secundum appears in the right of the septum primum 第2房间孔 第1房间隔 心内膜垫

Separation of the atrium 第2房间隔 第2房间隔上留有一 卵圆形孔 ——卵圆孔 第2房间孔 卵圆孔瓣 卵圆孔 oval passage --foramen ovale 心内膜垫 覆盖卵圆孔的第1房间 隔部分---卵圆孔瓣 Valve of foramen ovale

two septums fuse to separate atrium completely Separation of the atrium blood can flow from right atrium toward the left atrium before birth 血液经右房 左房 左房 右房 after birth 卵圆孔关闭 左、右心房完全分隔 two septums fuse to separate atrium completely

(3) Separation of the ventricles 心室底壁出现肌性嵴 -------室间隔肌部 Muscular part of interventricular septum 心内膜垫 左心室 右心室 室间隔肌部

Separation of the ventricles 第2房间隔 第2房间孔 肌部与心内膜垫间 ------室间孔 Interventricular foramen 心内膜垫 室间孔 室间隔肌部

Separation of the ventricles 肌部与心内膜垫间形 成隔膜---室间隔膜部 Membranous part of interventricular septum —— made up of bulbar ridge ,endocardial cushion and muscular part of interventricular septum 心内膜垫 室间隔膜部 室间隔肌部

Separation of the ventricles

（4）静脉窦的演变和永久性左、右心房的形成Evolution of the sinus venosus and formation of the permanent atrium right sinus horns left sinus horns vitelline vein umbilical vein common cardinal vein

proximal portion: coronary sinus distal part: oblique vein left sinus horn proximal portion: coronary sinus right sinus horn: right atrium right auricle

left auricle

(5) 动脉干与心球的分隔 Separation of the truncus arteriosus & bulbus cordis 第5周 动脉干嵴 动脉干 心球嵴 心球 动脉干嵴 truncal ridge 心球嵴 bulbar ridge

aortico-pulmonary septum two spiral ridges grow ， twist around each other and fuse to form a spiral aortico-pulmonary septum 主动脉 肺动脉 主动脉 肺动脉隔 嵴融合------主动脉肺动脉隔 aortico-pulmonary septum

Pulmonary trunk Ascending aorta

aortic valves pulmonary valves 半月瓣 隆起 半月瓣 aortic valves pulmonary valves

Ⅳ. Development and derivative of the aortic arches

3rd 4th Left: arch of the aorta 6th common carotid artery internal carotid artery 4th Left: arch of the aorta (7th intersegmental A ---left subclavian A) Right: brachiocephalic trunk (with 7th intersegmental A) subclavian artery 6th Proximal part: pulmonary artery Distal part: Right: disappear Left: ductus arteriosus

Ⅴ. Blood circulation of fetus and its changes after birth 1.Fetal circulation umbilical V→ducts venosus →inferior vena cava → right atrium →foramen ovale →left atrium →left ventricle → Ascending aorta → head and neck region →superior vena cava →right atrium →right ventrical → ductus arteriosus → descending aorta gut and lower region of the body placenta umbilical A

head L subclavian A ductus venosus portal V V from digestive tract veins from neck A L common carotid A upper limb innominate A superior vena cava aorta right atrium oval foramen left atrium left ventricle right ventricle pulmonary A pulmonary V ductus arteriosus descending aorta trunk inferior vena cava V from lower limb A of abdomen, pelvis,lower limb hepatic V ductus venosus portal V V from digestive tract liver   umbilical vein placenta umbilical A

胎儿血液循环 静脉导管

2.Circulatory changes after birth: (1)Umbilical A: lateral umbilical ligaments Umbilical V: ligamentum teres hepatis (2)Ductus venosus: ligamentus venosum (3) Ductus arteriosus: ligamentum arteriosum (4) Oval foramen: oval pit

Ⅴ.Congenital malformations of the cardiovascular system Atrial septal defect patency of the foramen ovale

2. Ventricular septal defect

3.Abnormal division of the truncus arteriosus and bulbus cordis (1)Transposition of aortic & pulmonary arteries 主 A 肺 A 右心室 左心室

(2) Stenosis of Aorta or Pulmonary Atery unequal division of aortico-pulmonary septum

(3) Persistent truncus arteriosus

(4)Tetralogy of Fallot pulmonary stenosis Overriding aorta ventricular septal defect hypertrophy of the right ventricle 肺A狭窄 主A骑跨 室间隔缺损 右心室肥大

4. Patent ductus arteriosus 正常 异常