Development of the Great Vessels and Conduc6on Tissue

Transcription

1 Development of the Great Vessels and Conduc6on Tissue

2 Development of the heart fields h:p://php.med.unsw.edu.au/embryology/ index.php?6tle=advanced_- _Heart_Fields! 2

3 Septa6on of the Bulbus Cordis Bulbus Cordis AV Canal Ventricle Looking at a sagital sec6on of the heart early in development the bulbus cordis is con6nuous with the ventricle which is con6nuous with the atria. As the AV canal shios to the right the bulbus move to the right as well.

4 Septa6on of the Bulbus Cordis A P A P The next three slides make the point via cross sec6ons that the aorta and pulmonary arteries rotate around each other. This means the septum between them changes posi6on from superior to inferior as well.

5 Septa6on of the Bulbus Cordis A P A P

6 Septa6on of the Bulbus Cordis A P P A

7 Migra6on of neural crest cells Neural crest cells migrate from the 3ed, 4th and 6th pharyngeal arches to form some of the popula6on of cells forming the aor6copulmonary septum.

8 Septa6on of the Bulbus Cordis Truncal (Conal) Swellings Bulbus Cordis The cardiac jelly in the region of the truncus and conus adds the neural crest cells and expands as truncal swellings.

9 Septa6on of the Bulbus Cordis Aorticopulmonary septum These swellings grow toward each other to meet and form the septum between the aorta and pulmonary artery. Aorta Pulmonary

10 Septa6on of the Bulbus Cordis 1 2 Anterior The aor6copulmonary septum then rotates as it moves inferiorly. However, the exact mechanism for that rota6on remains unclear.

11 However, the aor6copulmonary septum must form properly for the IV septum to be completed. Septa6on of the Bulbus Cordis Aorta Pulmonary Conal Ridges IV Foramen Membranous Interventricular Septum Endocarial Cushion Muscular IV Septum

12 Embryonic Circula6on Common Cardinal Vein Dorsal Aorta Anterior Cardinal Vein Brain and Spinal Cord Posterior Cardinal Vein Umbilical Aor6c Arches Yolk Sac Umbilical Vein Ventricle Atria Vitelline & Vein Blood leaves the truncus and moves to the aor6c arches. There is an aor6c arch for each pharyngeal arch.

13 Development of the Arteries Aor6c Sac Dorsal Aorta Ventral Aorta 1 st Aor6c Arch 2 nd Aor6c Arch 3 rd Aor6c Arch 4 th Aor6c Arch 5 th Aor6c Arch 6 th Aor6c Arch Internal External R. Common R. Pulmonary Pulmonary Trunk R. Subclavian L. Pulmonary Ductus Arteriosus 7 th Intersegmental Descending Aorta L. Subclavian They can be depicted this way for descrip6ve purposed explaining the fate of the arches.

14 Development of the Arteries Dorsal Aorta Ventral Aorta 1 st Aor6c Arch 2 nd Aor6c Arch 3 rd Aor6c Arch 4 th Aor6c Arch 5 th Aor6c Arch 6 th Aor6c Arch Aor6c Sac 7 th Intersegmental The first arch degenerates shortly aoer the second arch develops.

15 Development of the Arteries Dorsal Aorta Ventral Aorta 1 st Aor6c Arch 2 nd Aor6c Arch 3 rd Aor6c Arch 4 th Aor6c Arch 5 th Aor6c Arch 6 th Aor6c Arch Aor6c Sac 7 th Intersegmental The second arch degenerates shortly aoer the third arch develops

16 The distal third arch and the distal dorsal aorta form the internal caro6d artery on both sides of the body. Development of the Arteries Aor6c Sac Dorsal Aorta Ventral Aorta 1 st Aor6c Arch 2 nd Aor6c Arch 3 rd Aor6c Arch 4 th Aor6c Arch 5 th Aor6c Arch 6 th Aor6c Arch Internal External R. Common R. Pulmonary Pulmonary Trunk R. Subclavian L. Pulmonary Ductus Arteriosus 7 th Intersegmental Descending Aorta L. Subclavian

17 The proximal third arch and the ventral aorta between the 3rd and 4th arches forms the common caro6d artery on both sides of the body. Development of the Arteries Aor6c Sac Dorsal Aorta Ventral Aorta 1 st Aor6c Arch 2 nd Aor6c Arch 3 rd Aor6c Arch 4 th Aor6c Arch 5 th Aor6c Arch 6 th Aor6c Arch Internal External R. Common R. Pulmonary Pulmonary Trunk R. Subclavian L. Pulmonary Ductus Arteriosus 7 th Intersegmental Descending Aorta L. Subclavian

18 Development of the Arteries Aor6c Sac Dorsal Aorta Ventral Aorta 1 st Aor6c Arch 2 nd Aor6c Arch 3 rd Aor6c Arch 4 th Aor6c Arch 5 th Aor6c Arch 6 th Aor6c Arch Internal External R. Common R. Pulmonary Pulmonary Trunk R. Subclavian L. Pulmonary Ductus Arteriosus 7 th Intersegmental Descending Aorta L. Subclavian New vessels arise in the middle of the 3rd arch and form the external caro6d arteries.

19 Development of the Arteries Aor6c Sac Dorsal Aorta Ventral Aorta 1 st Aor6c Arch 2 nd Aor6c Arch 3 rd Aor6c Arch 4 th Aor6c Arch 5 th Aor6c Arch 6 th Aor6c Arch Internal External R. Common R. Pulmonary Pulmonary Trunk R. Subclavian L. Pulmonary Ductus Arteriosus 7 th Intersegmental Descending Aorta L. Subclavian The truncus and thefourth arch on the leo along with the dorsal aorta form the ascending aorta, the arch of the aorta and the descending aorta respec6vely.

20 Development of the Arteries Aor6c Sac Dorsal Aorta Ventral Aorta 1 st Aor6c Arch 2 nd Aor6c Arch 3 rd Aor6c Arch 4 th Aor6c Arch 5 th Aor6c Arch 6 th Aor6c Arch Internal External R. Common R. Pulmonary Pulmonary Trunk R. Subclavian L. Pulmonary Ductus Arteriosus 7 th Intersegmental Descending Aorta L. Subclavian ON the right the 4th arch and the dorsal aorta and 7th intersegmental artery form the right subclavian artery.

21 Development of the Arteries Aor6c Sac Dorsal Aorta Ventral Aorta 1 st Aor6c Arch 2 nd Aor6c Arch 3 rd Aor6c Arch 4 th Aor6c Arch 5 th Aor6c Arch 6 th Aor6c Arch Internal External R. Common R. Pulmonary Pulmonary Trunk R. Subclavian L. Pulmonary Ductus Arteriosus 7 th Intersegmental Descending Aorta L. Subclavian The 7th intersegmental artery gives rise to the leo subclavian artery.

22 Development of the Arteries Aor6c Sac Dorsal Aorta Ventral Aorta 1 st Aor6c Arch 2 nd Aor6c Arch 3 rd Aor6c Arch 4 th Aor6c Arch 5 th Aor6c Arch 6 th Aor6c Arch Internal External R. Common R. Pulmonary Pulmonary Trunk R. Subclavian L. Pulmonary Ductus Arteriosus 7 th Intersegmental Descending Aorta L. Subclavian The right ventral aorta between the 4th and 6th arches forms the brachiocephalic artery. Which then connects the aorta to the right common caro6d artery and the right subclavian artery.

23 Development of the Arteries Aor6c Sac Dorsal Aorta Ventral Aorta 1 st Aor6c Arch 2 nd Aor6c Arch 3 rd Aor6c Arch 4 th Aor6c Arch 5 th Aor6c Arch 6 th Aor6c Arch Internal External R. Common R. Pulmonary Pulmonary Trunk R. Subclavian L. Pulmonary Ductus Arteriosus 7 th Intersegmental Descending Aorta L. Subclavian The proximal sixth arch forms the right and leo pulmonary arteries along with some of the main pulmonary trunk.

24 Development of the Arteries Aor6c Sac Dorsal Aorta Ventral Aorta 1 st Aor6c Arch 2 nd Aor6c Arch 3 rd Aor6c Arch 4 th Aor6c Arch 5 th Aor6c Arch 6 th Aor6c Arch Internal External R. Common Brachiocephalic R. Pulmonary Pulmonary Trunk R. Subclavian L. Pulmonary Ductus Arteriosus 7 th Intersegmental Descending Aorta L. Subclavian On the right the distal sixth arch degenerates while on the right it remains as a shunt to take blood from the pulmonary system to the systemic system in the fetus.

25 Embryonic Circula6on Common Cardinal Vein Dorsal Aorta Anterior Cardinal Vein Brain and Spinal Cord Posterior Cardinal Vein Umbilical Aor6c Arches Yolk Sac Umbilical Vein Ventricle Atria Vitelline & Vein

26 Development of Veins anterior cardinal vein subclavian vein internal jugular vein r. & l. brachio- cephalic veins sinus venosus external jugular vein coronary sinus common cardinal vein SVC posterior cardinal vein thymicothyroid anastomosis azygos vein In terms of the veins there are the systemic veins ini6ally. They are the common cardinal veins, the anterior cardinal veins and the posterior cardinal veins.

27 Development of Veins anterior cardinal vein subclavian vein internal jugular vein r. & l. brachio- cephalic veins sinus venosus external jugular vein coronary sinus common cardinal vein SVC posterior cardinal vein thymicothyroid anastomosis azygos vein The brachiocephalic veins form from the anterior cardinal on the right and a new system of veins called the thymicothyroid anastomosis on the leo which then drains all the blood from the leo side of the head and neck to the superior vena cava.

28 Development of Veins anterior cardinal vein subclavian vein internal jugular vein r. & l. brachio- cephalic veins sinus venosus external jugular vein coronary sinus common cardinal vein SVC posterior cardinal vein thymicothyroid anastomosis azygos vein The superior vena cava develops from the right anterior cardinal vein and the right common cardinal vein.

29 Development of Veins anterior cardinal vein subclavian vein internal jugular vein r. & l. brachio- cephalic veins sinus venosus external jugular vein coronary sinus common cardinal vein SVC posterior cardinal vein thymicothyroid anastomosis azygos vein The azygos vein develops from the right posterior cardinal vein and runs posterior to the lung root before arching anteriorly to enter the SVC.

30 Development of Veins anterior cardinal vein subclavian vein internal jugular vein r. & l. brachio- cephalic veins sinus venosus external jugular vein coronary sinus common cardinal vein SVC posterior cardinal vein thymicothyroid anastomosis azygos vein The coronary sinus develops from the leo common cardinal vein.

31 Because of the development of many abdominal organs several new vessels appear. Ini6ally there is a posterior cardinal vein. Then there appears a set of subcardinal veins and supracardinal veins. These all contribute to the abdominal and pelvic vasculature. anterior cardinal v. 7 th intersegmental v. right vitelline v. sinus venosus right brachiocephalic SVC hepaac IVC internal jugular v. external jugular v. subclavian v. le? brachiocephalic right umbilical v. azygos v. hemiazygos v. right subcardinal v. subcardinal anastomosis supracardinal v. posterior cardinal anastomosis suprarenal v. renal v. postrenal IVC common iliac veins renal IVC gonadal veins

32 Development of Inferior Vena Cava The inferior vena cava develops from several sources. The renal segment develops from the right subcardinal vein (purple). anterior cardinal v. 7 th intersegmental v. right vitelline v. sinus venosus right brachiocephalic SVC hepaac IVC internal jugular v. external jugular v. subclavian v. le? brachiocephalic right umbilical v. azygos v. hemiazygos v. right subcardinal v. subcardinal anastomosis supracardinal v. posterior cardinal anastomosis suprarenal v. renal v. postrenal IVC common iliac veins renal IVC gonadal veins

33 Development of Inferior Vena Cava The inferior vena cava develops from several sources. The hepa6c segment develops from a new vessel called the hepato- subcardinal anastomosis (yellow). anterior cardinal v. 7 th intersegmental v. right vitelline v. sinus venosus right brachiocephalic SVC hepaac IVC internal jugular v. external jugular v. subclavian v. le? brachiocephalic right umbilical v. azygos v. hemiazygos v. right subcardinal v. subcardinal anastomosis supracardinal v. posterior cardinal anastomosis suprarenal v. renal v. postrenal IVC common iliac veins renal IVC gonadal veins

34 Development of Inferior Vena Cava The most proximal por6on of the inferior vena cava develops from the right vitelline vein (red). anterior cardinal v. 7 th intersegmental v. right vitelline v. sinus venosus right brachiocephalic SVC hepaac IVC internal jugular v. external jugular v. subclavian v. le? brachiocephalic right umbilical v. azygos v. hemiazygos v. right subcardinal v. subcardinal anastomosis supracardinal v. posterior cardinal anastomosis suprarenal v. renal v. postrenal IVC common iliac veins renal IVC gonadal veins

35 Development of Inferior Vena Cava The distal por6on of the inferior vena cava develops from the distal supracardinal vein and perhaps the distal posterior subcardinal vein (navy blue). anterior cardinal v. 7 th intersegmental v. right vitelline v. sinus venosus right brachiocephalic SVC hepaac IVC internal jugular v. external jugular v. subclavian v. le? brachiocephalic right umbilical v. azygos v. hemiazygos v. right subcardinal v. subcardinal anastomosis supracardinal v. posterior cardinal anastomosis suprarenal v. renal v. postrenal IVC common iliac veins renal IVC gonadal veins

36 Development of Portal Vein foregut liver umbilical veins vitelline veins The vitelline and umbilical veins arelocated on either side oof the foregut (yellow).

37 The distal vitelline veins are going to develop anastomoses between the vessels and eventually form the portal vein (and perhaps the superior mesenteric vein) (green). Development of Portal Vein foregut liver umbilical veins vitelline veins

38 Development of Veins foregut hepatic veins liver vitelline veins umbilical veins The proximal vitelline veins will form the main hepa6c veins that empty into the inferior vena cava (orange).

39 Development of Veins foregut inferior vena cava liver vitelline veins umbilical veins The proximal part of the inferior vena cava was derived from the right vitelline vein (red).

40 Development of Veins foregut ductus venosus liver umbilical veins vitelline veins As the liver and kidneys grow they obliterate the right umbilical vein. It degenerates and blood from the placenta flows through the leo umbilical vein. However, as the liver enlarges a new vessel develops so that placental blood will bypass the liver. This is the ductus venosus (blue).

41 Development of Veins foregut ductus venosus ligamentum venosum liver umbilical veins vitelline veins umbilical vein ligamentum teres A birth the umbilical vein and the ductus venosus are no longer patent and become connec6ve 6ssue cords called the ligamentum teres (purple) and the ligamentum venosum (blue) respec6vely.

42 Conversion of fetal circula6on to newborn circula6on Fetal Circula6on Umbilical vein Ductus venosus Inferior vena cava Pulmonary v. Right atrium FO LeO atrium Right ventricle LeO Ventricle Pulmonary A. DA Aorta R & L Pulmonary A Aorta Newborn circula6on Inferior vena cava Right atrium Right ventricle Pulmonary artery Lungs Pulmonary Veins LeO atrium LeO ventricle Aorta

43 At birth there is: Closure of the umbilical vein Closure of the ductus venosus Closure of the foramen ovale Closure of the ductus arteriosus. Increased O 2 par6al pressure. Bradykinins are released from the lungs. Prior to birth prostaglandins keep fetal vasculature dialated.

44 Conduc6on 6ssue!!!!! Ini6al heart myocardium From second heart field The ini6al myocardial mantle gives rise to three rings of 6ssue.

45 SA Node SA node cells develop from mesenchymal cells that are precursors of the sinus venosus 6ssue. Cells Tbx18 posi6ve. Then Tbx3 posi6ve Leads to ac6va6on of CX40 Cx43 Nppa Scn5a All SA node genes mesenchyme

46 AV Node and bundle AV Node cells Cx45 posi6ve Cx30 posi6ve Tbx3 posi6ve AV ring gives rise to AV node cells AV bundle develops from crest of muscular IV septum Rest of AV canal 6ssue becomes annulus fibrosus. Insulates atria from ventricles Otherwise accessory pathways. AV canal 6ssue

47 Mesoderm gives rise to cardiac muscle cells and endocardial cells. Neural crest cells develop into smooth muscle of ouklow tract and cardiac ganglia. Proepicardium epicardium and coronary vessels.

48 TABLE 1 Mean Heart Rates for Embryos at 6 8 Weeks GestaAon! Group Gesta6onal Age (days) Mean Heart Rate ±SD (beats/min)* 1 (n = 456) ± 14 2 (n = 522) ± 15 3 (n = 558) ± 14 4 (n = 628) ± 13 J Clin Ultrasound Jan;26(1):33-6. Embryonic heart rate in early pregnancy. Stefos TI, Lolis DE, So6riadis AJ, Ziakas GV.

49 Early Fetal Heart Rates 6 weeks 7 weeks 8 weeks 9 weeks 10 weeks FHR (bpm) 117 ± ± ± ± ± 6 Włoch A, Rozmus- Warcholinska W, Czuba B, Borowski D, Włoch S, Cnota W, Sodowski K, Szaflik K, Huhta JC. J Matern Fetal Neonatal Med Jul;20(7):533-9.

50 Normal fetal heart rate is between 110 and 160 beats per minute (bpm) throughout pregnancy. Later in pregnancy the heart rate may slow as the vagal innerva6on matures.

51 h:p://php.med.unsw.edu.au/embryology/index.php? 6tle=File:Advanced_Heart_Development_Timeline.jpg 51