Development of the Great Vessels and Conduction Tissue new...Aug 06, 2014 · Pulmonary* Trunk...

Development of the Great Vessels and Conduc6on Tissue

Development of the heart fields

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Septa6on of the Bulbus Cordis

Bulbus Cordis

Ventricle

AV Canal

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.


AP 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.


A PA P


PA

AP

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.


Bulbus Cordis

Truncal (Conal) Swellings

The cardiac jelly in the region of the truncus and conus adds the neural crest cells and expands as truncal swellings.


Aorticopulmonary septum

Aorta Pulmonary

Artery

These swellings grow toward each other to meet and form the septum between the aorta and pulmonary artery.

1

2

3

31 2


Anterior

The aor6copulmonary septum then rotates as it moves inferiorly. However, the exact mechanism for that rota6on remains unclear.

Pulmonary ArteryAorta

Conal Ridges

IV Foramen

Muscular IV SeptumEndocarial

Cushion


Membranous Interventricular

SeptumHowever, the aor6copulmonary septum must form properly for the IV septum to be completed.

Embryonic Circula6onBrain and Spinal CordDorsal Aorta

Aor6c Arches

Ventricle

Atria

Anterior Cardinal Vein

Posterior Cardinal Vein

Umbilical Vein

Umbilical Artery

Yolk Sac

Vitelline Artery & Vein

Common Cardinal Vein

Blood leaves the truncus and moves to the aor6c arches. There is an aor6c arch for each pharyngeal arch.

Development of the Arteries

Internal Caro6d

External Caro6d

Pulmonary Trunk

R. Common Caro6d

Ductus Arteriosus

L. Subclavian Artery

Descending Aorta

R. Pulmonary Artery

R. Subclavian Artery

L. Pulmonary Artery

Dorsal AortaVentral Aorta1st Aor6c Arch

3rd Aor6c Arch

4th Aor6c Arch5th Aor6c Arch6th Aor6c Arch

2nd Aor6c Arch

7th Intersegmental Artery

Aor6c Sac

They can be depicted this way for descrip6ve purposed explaining the fate of the arches.



3rd Aor6c Arch


2nd Aor6c Arch


Aor6c Sac

The first arch degenerates shortly aOer the second arch develops.



3rd Aor6c Arch


2nd Aor6c Arch


Aor6c Sac

The second arch degenerates shortly aOer the third arch develops



3rd Aor6c Arch


2nd Aor6c Arch


Aor6c Sac

Internal Caro6d

External Caro6d

Pulmonary Trunk

R. Common Caro6d

Ductus Arteriosus


Descending Aorta

R. Pulmonary Artery


L. Pulmonary Artery


3rd Aor6c Arch


2nd Aor6c Arch


Aor6c Sac

The distal third arch and the distal dorsal aorta form the internal caro6d artery on both sides of the body.



3rd Aor6c Arch


2nd Aor6c Arch


Aor6c Sac

Internal Caro6d

External Caro6d

Pulmonary Trunk

R. Common Caro6d

Ductus Arteriosus


Descending Aorta

R. Pulmonary Artery


L. Pulmonary Artery


3rd Aor6c Arch


2nd Aor6c Arch


Aor6c Sac

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.



3rd Aor6c Arch


2nd Aor6c Arch


Aor6c Sac

Internal Caro6d

External Caro6d

Pulmonary Trunk

R. Common Caro6d

Ductus Arteriosus


Descending Aorta

R. Pulmonary Artery


L. Pulmonary Artery


3rd Aor6c Arch


2nd Aor6c Arch


Aor6c Sac

New vessels arise in the middle of the 3rd arch and form the external caro6d arteries.



3rd Aor6c Arch


2nd Aor6c Arch


Aor6c Sac

Internal Caro6d

External Caro6d

Pulmonary Trunk

R. Common Caro6d

Ductus Arteriosus


Descending Aorta

R. Pulmonary Artery


L. Pulmonary Artery


3rd Aor6c Arch


2nd Aor6c Arch


Aor6c Sac

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.



3rd Aor6c Arch


2nd Aor6c Arch


Aor6c Sac

Internal Caro6d

External Caro6d

Pulmonary Trunk

R. Common Caro6d

Ductus Arteriosus


Descending Aorta

R. Pulmonary Artery


L. Pulmonary Artery


3rd Aor6c Arch


2nd Aor6c Arch


Aor6c Sac

ON the right the 4th arch and the dorsal aorta and 7th intersegmental artery form the right subclavian artery.



3rd Aor6c Arch


2nd Aor6c Arch


Aor6c Sac

Internal Caro6d

External Caro6d

Pulmonary Trunk

R. Common Caro6d

Ductus Arteriosus


Descending Aorta

R. Pulmonary Artery


L. Pulmonary Artery


3rd Aor6c Arch


2nd Aor6c Arch


Aor6c Sac

The 7th intersegmental artery gives rise to the leO subclavian artery.



3rd Aor6c Arch


2nd Aor6c Arch


Aor6c Sac

Internal Caro6d

External Caro6d

Pulmonary Trunk

R. Common Caro6d

Ductus Arteriosus


Descending Aorta

R. Pulmonary Artery


L. Pulmonary Artery


3rd Aor6c Arch


2nd Aor6c Arch


Aor6c Sac

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.



3rd Aor6c Arch


2nd Aor6c Arch


Aor6c Sac

Internal Caro6d

External Caro6d

Pulmonary Trunk

R. Common Caro6d

Ductus Arteriosus


Descending Aorta

R. Pulmonary Artery


L. Pulmonary Artery


3rd Aor6c Arch


2nd Aor6c Arch


Aor6c Sac

The proximal sixth arch forms the right and leO pulmonary arteries along with some of the main pulmonary trunk.



3rd Aor6c Arch


2nd Aor6c Arch


Aor6c Sac

Internal Caro6d

External Caro6d

Pulmonary Trunk

R. Common Caro6d

Ductus Arteriosus


Descending Aorta

R. Pulmonary Artery


L. Pulmonary Artery


3rd Aor6c Arch


2nd Aor6c Arch


Aor6c Sac

Brachiocephalic Artery

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.

Embryonic Circula6onBrain and Spinal CordDorsal Aorta

Aor6c Arches

Ventricle

Atria

Anterior Cardinal Vein

Posterior Cardinal Vein

Umbilical Vein

Umbilical Artery

Yolk Sac

Vitelline Artery & Vein

Common Cardinal Vein

Development of Veinsanterior

cardinal veininternal

jugular vein

posterior cardinal vein

common cardinal vein

thymicothyroid anastomosis

subclavian vein

external jugular vein

azygos vein

coronary sinus

r. & l. brachio-‐cephalic veins

SVC

sinus venosus

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.



jugular vein




subclavian vein


azygos vein

coronary sinus


SVC

sinus venosus

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.



jugular vein




subclavian vein


azygos vein

coronary sinus


SVC

sinus venosus

The superior vena cava develops from the right anterior cardinal vein and the right common cardinal vein.



jugular vein




subclavian vein


azygos vein

coronary sinus


SVC

sinus venosus

The azygos vein develops from the right posterior cardinal vein and runs posterior to the lung root before arching anteriorly to enter the SVC.



jugular vein




subclavian vein


azygos vein

coronary sinus


SVC

sinus venosus

The coronary sinus develops from the leO common cardinal vein.

anterior cardinal v.

7th intersegmental v.

right vitelline v.

right umbilical v.

right subcardinal v.

subcardinal anastomosis

supracardinal v.

subclavian v.le? brachiocephalic

right brachiocephalic

hemiazygos v.

gonadal veins

common iliac veins

postrenal IVC

internal jugular v.

external jugular v.

SVC

azygos v.

hepaAc IVC

renal IVCsuprarenal v.

renal v.

posterior cardinal anastomosis

sinus venosus

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.

Development of Inferior Vena Cava



right vitelline v.

right umbilical v.



supracardinal v.



hemiazygos v.

gonadal veins

common iliac veins

postrenal IVC

internal jugular v.

external jugular v.

SVC

azygos v.

hepaAc IVC


renal v.


sinus venosus

The inferior vena cava develops from several sources. The renal segment develops from the right subcardinal vein (purple).



right vitelline v.

right umbilical v.



supracardinal v.



hemiazygos v.

gonadal veins

common iliac veins

postrenal IVC

internal jugular v.

external jugular v.

SVC

azygos v.

hepaAc IVC


renal v.


sinus venosus

Development of Inferior Vena CavaThe inferior vena cava develops from several sources. The hepa6c segment develops from a new vessel called the hepato-‐subcardinal anastomosis (yellow).



right vitelline v.

right umbilical v.



supracardinal v.



hemiazygos v.

gonadal veins

common iliac veins

postrenal IVC

internal jugular v.

external jugular v.

SVC

azygos v.

hepaAc IVC


renal v.


sinus venosus

Development of Inferior Vena CavaThe most proximal por6on of the inferior vena cava develops from the right vitelline vein (red).



right vitelline v.

right umbilical v.



supracardinal v.



hemiazygos v.

gonadal veins

common iliac veins

postrenal IVC

internal jugular v.

external jugular v.

SVC

azygos v.

hepaAc IVC


renal v.


sinus venosus

Development of Inferior Vena CavaThe distal por6on of the inferior vena cava develops from the distal supracardinal vein and perhaps the distal posterior subcardinal vein (navy blue).

Development of Portal Vein

foregut

vitelline veins

umbilical veins

liver

The vitelline and umbilical veins arelocated on either side oof the foregut (yellow).

Development of Portal Vein

foregut

vitelline veins

umbilical veins

liver

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 Veins

foregut

vitelline veins

umbilical veins

liver

hepatic veins

The proximal vitelline veins will form the main hepa6c veins that empty into the inferior vena cava (orange).


foregut

vitelline veins

umbilical veins

liver

inferior vena cava

The proximal part of the inferior vena cava was derived from the right vitelline vein (red).


foregut

vitelline veins

umbilical veins

liver

ductus venosus

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).


foregut

vitelline veins

umbilical veins

liver

ductus venosus

umbilical vein

ligamentum venosum

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.

• 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

Conversion of fetal circula6on to newborn circula6on

Fetal Circula6on Newborn circula6on• Inferior vena cava • Right atrium • Right ventricle • Pulmonary artery • Lungs • Pulmonary Veins • LeO atrium • LeO ventricle • Aorta

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 O2 par6al pressure.

– Bradykinins are released from the lungs. – Prior to birth prostaglandins keep fetal vasculature dialated.

!!!!!

Ini6al heart myocardium From second heart field

Conduc6on 6ssue

The ini6al myocardial mantle gives rise to three rings of 6ssue.

SA NodeSA 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

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

• 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.

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) 42–45 111 ± 14 2 (n = 522) 46–49 125 ± 15 3 (n = 558) 50–52 145 ± 14 4 (n = 628) 53–56 157 ± 13

J Clin Ultrasound. 1998 Jan;26(1):33-‐6. Embryonic heart rate in early pregnancy. Stefos TI, Lolis DE, So6riadis AJ, Ziakas GV.

http://www.ncbi.nlm.nih.gov/pubmed?term=%2522Stefos%2520TI%2522%255BAuthor%255D&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVAbstract

http://www.ncbi.nlm.nih.gov/pubmed?term=%2522Lolis%2520DE%2522%255BAuthor%255D&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVAbstract

http://www.ncbi.nlm.nih.gov/pubmed?term=%2522Sotiriadis%2520AJ%2522%255BAuthor%255D&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVAbstract

http://www.ncbi.nlm.nih.gov/pubmed?term=%2522Ziakas%2520GV%2522%255BAuthor%255D&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVAbstract

Early Fetal Heart Rates

6 weeks 7 weeks 8 weeks 9 weeks 10 weeks

FHR (bpm) 117 ± 6 129 ± 18 154 ± 16 169 ± 12 171 ± 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. 2007 Jul;20(7):533-‐9.

• 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.

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

http://php.med.unsw.edu.au/embryology/index.php?title=File:Advanced_Heart_Development_Timeline.jpg

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Development of the Great Vessels and Conduction Tissue new...Aug 06, 2014 · Pulmonary* Trunk...

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