The Cardiovascular System (Part I) 黃敏銓
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The Cardiovascular System (Part I) 黃敏銓 [email protected] 德國敏斯特大學 細胞生物學/遺傳學 博士 解剖學暨細胞生物學研究所 助理教授 1 The Cardiovascular System 1. The first major system to function 2. The primordial heart and vascular system appear in the middle of the third week 3. The heart starts to function at the beginning of the fourth week 2 The cardiovascular system is derived mainly from: • Splanchnic mesoderm • Paraxial and lateral mesoderm • Neural crest cells 3 Development of heart 4 Eraly development of heart Heart primordium Angioblastic cord 18 days Angioblastic cord 5 Development of veins Three paired veins drain into the tubular heart of a 4-week embryo • Vitelline veins: poorly oxygenated blood from yolk sac • Umbilical veins: oxygenated blood from the primordial placenta • Common cardinal veins: poorly oxygenated blood from the body of the embryo 6 Three paired veins Cardinal veins 26 days Sinus venosus Blue color Vitelline vein Umbilical vein 7 Three paired veins enter into the sinus venosus Left Right Dorsal view 24 days 8 Vitelline veins Hepatic vein and portal vein Left Right Hepatic vein: right vitelline vein Liver Portal vein: vitelline veins 9 Dorsal view (7 weeks) Duodenum Umbilical veins Umbilical vein & ductus venosus: left umbilical vein Left Right 7th week (Ligamentum venosum) 10 Dorsal view Anterior cardinal veins 1. Brachiocephalic veins 7 weeks Anastomosis between anterior cardinal veins Left Right 8 weeks Left brachiocephalic vein Right brachiocephalic vein 11 Dorsal view Superior vena cava Dorsal view Superior vena cava Right anterior cardinal vein Right common cardinal vein 12 Left Right Posterior cardinal veins: root of azygos v. and common iliac veins 6 weeks Adult Azygos v. Posterior cardinal vein (mesonephroi) Common iliac v. 13 Right Left Subcardinal veins and supracardinal veins replace and supplement posterior cardinal veins Supracardinal v. Posterior cardinal v. Subcardinal v. Right Left 6 weeks 7 weeks 14 Subcardinal veins IVC (prerenal seg.) Stem of L. renal v. R. suprarenal v. L. suprarenal v. Subcardinal vein R. gonadal v. L. gonadal v. 6 weeks Adult 15 Right Left Supracardinal veins Azygos v. Hemiazygos v. IVC (postrenal seg.) degeneration 8 weeks Right Adult Left 16 Supracardinal vein Inferior vena cava (IVC) IVC (hepatic segment): hepatic v. and sinusoids IVC (prerenal segment): R. subcardinal v. IVC (renal segment): Subcardinal-supracardinal anastomosis IVC (postrenal segment): R. supracardinal v. 17 Right Adult Left Dorsal intersegmental arteries Aortic arches Dorsal aorta Pharyngeal arches Aortic sac 4th-5th week (26 days) 18 Dorsal intersegmental arteries •Neck: vertebral arteries •Thorax: intercostal arteries • Abdomen: – lumbar arteries – 5th pair: common iliac arteries •Sacrum: lateral sacral arteries • Caudal end of dorsal aorta: median sacral artery. 19 Vitelline arteries • Celiac trunk: foregut • Superior mesenteric artery: midgut • Inferior mesenteric artery: hindgut 20 Umbilical arteries • Proximal parts – Internal iliac arteries – Superior vesical arteries • Distal parts – Medial umbilical ligments 21 Further development of heart 22 Fusion of endocardial heart tubes Ventral views 23 Fusion of endocardial heart tubes Pericardial coelom 20-day Dorsal mesocardium Epicardium Cardiac jelly 22-day Primordial myocardium 24 (from splanchnic mesoderm) Formation of heart wall and transverse pericardial sinus Endocardium Sinus venosus Myocardium Epicardium 28 days 25 Transverse pericardial sinus 26 Relative position of human embryo during the 4th week Head fold Oropharyngeal membrane foregut Tubular heart formation Septum transversum Pericardial cavity 27 U-shaped bulboventricular loop Primordial atrium Sinus venosus Truncus arteriosus Bulbus cordis Primordial ventricle 24 days 28 Lateral expansions of the sinus venosus Left horn of sinus venosus Right horn of sinus venosus Dorsal view of the heart (about 26 days) 29 Circulation through primordial heart 6 Sinus venosus 1 2 3 5 4 30 End of 4th week: unidirectional flow 休息10分鐘 31 Partitioning of primordial heart • begins around middle of the 4th week. •is completed by the end of the 5th week. • includes partitioning of: – Atrioventricular canal – Primordial atrium – Primordial ventricle 32 Partitioning of Atrioventricular Canal 5th week Fused endocardial canal End of 4th week Endocardial cushions (from cardiac Left AV canal jelly) Transformed endocardial cushions contribute to the 33 formation of valves and membranous septa of the heart. AV endocardial cushions the primordia of the valves and membranous septa Bone morphogenetic protein (BMP2) 34 Partitioning of primordial atrium • begins at the end of the 4th week. • is divided into right and left atria by: – Septum primum – Septum secundum 35 Septum primum Septum primum Endocardial cushion Septum secundum Foramen secundum Foramen primum 36 Septum primum Septum primum Foramum primum Foramum primum Foramum secundum Foramum primum Septum secundum Foramum secundum Septum primum 37 Septum secundum Septum secundum (upper limb) Foramen secundum Oval foramen Valve of oval foramen (from septum primum) Oval foramen Valve (from septum primum) 38 Valve of oval foramen Septum primum Septum secundum Oval foramen (open) Valve of oval foramen 39 Oval fossa is a remnant of oval foramen Before birth After birth Septum secundum Oval fossa Oval foramen Septum primum (valve of oval foramen) 40 Development of sinus venosus Opening of sinus venosus into primordial atrium Left horn of sinus venosus Right horn of sinus venosus Left Right Dorsal view (4 th week) 41 Progressive enlargement of the right horn results from two left-to-right shunts of blood Dorsal view (7 weeks)42 Left Right Doral view Primordial atrium 26 days Right horn of sinus venosus Left horn of sinus venosus Sinus venarum of right atrium 8 weeks Coronary sinus 43 Left Right Right sinuatrial valve → Left sinuatrial valve → • Crista terminalis fused with septum secundum → • Valve of IVC Interatrial septum • Valve of coronary sinus Crista terminalis Valve of coronary sinus Valve of inferior vena cava 44 Right Left Absorption of pulmonary vein into left atrium 5 weeks 6 weeks Primordial pulmonary vein Primordial left atrium Smooth-walled part of left atrium Left auricle 8 weeks 45 Right Left Myocardial sleeves atrial fibrillation 46 Partitioning of primordial ventricle Fused endocardial cushions Interventricular foramen Expansion Interventricular septum 5th week (muscular part) 47 Right Left Closure of the interventricular foramen Right bulbar ridge Left bulbar IV foramen ridge Fused endocardial cushions Membranous part of IV septum 48 7 weeks Cavitation of the ventricular walls forms a sponge-work of muscular bundles – trabeculae carneae 5 weeks 6 weeks 20 weeks Chordae tendinae 7 weeks Trabeculae carneae Papillary muscle 49 Right Left Partitioning of Bulbus Cordis and Truncus Arteriosus Truncus arteriosus Truncal ridge Bulbus cordis Bulbar ridge 5 weeks Aorta Aorticopulmonary septum Pulmonary trunk 6 weeks 50 Spiral form of Aorticopulmonary Septum 51 Bulbus cordis incorporates into the walls of ventricles Conus arteriosus (infundibulum) Aortic vestibule 52 Development of cardiac valves Swellings of subendothelial tissue Dorsal valve swelling Bulbar ridges Ventral valve swelling 53 Hollowing and thinning of valve swellings Valve swelling 54 Conducting system of heart Sinuatrial node (5 th week) Atrioventricular node Atrioventricular bundle Branches of AV bundle Right Left 55.