UNSW Embryology

Cardiovascular System Development- Stage 22

© Dr Mark Hill (2008)

Acknowledgements

Introduction

This page shows the Carnegie stage 22 embryo images that relate to cardiac development. The small image excerpts show specific features, which can then be observed in the linked complete sections.

Page Links: Introduction | Serial Sections | Serial Section table (Stage 22) |

Stage 22 Cardiovascular 3D Model

The individual serial slices have also been incorporated into a 3D model of this embryo Cardiovasular System.

Stage 22 Embryo

These are scaled image excerpts, click on image or section name to see full size section for details.

	E4: In centre of picture, portion of left ventricle wall. Righthandside- body wall. Lefthand side- diaphragm and liver. Centre bottom- oseophagus, thoracic aorta, and inferior vena cava.
	E3: Section through all four chambers of heart. Ventricles. Diaphragm and liver. Pericardium and cavity. R atrium and two cusps of the atrioventricular valve. L atrium and its auricle. Thoracic aorta. Inferior vena cava. Coronary sinus.
	E2: Section through all four chambers of heart. Ventricles. Right venous valve. Between the tiny ridge of the septum secundum of the R atrium and the R venous valve. right atrium- drainage of the inferior vena cava (cf. E3). R atrioventricular canal. Septum primum. left atrium- drainage sites of R and L pulmonary veins.
	E1: Section through all four chambers of heart. left ventricle- outflow tract close to origin of ascending aorta. Deep coronary sulcus and transverse pericardial sinus. right atrium- R venous valve of the inferior vena cava, the small septum secundum, the aperture in the dorsal part of septum primum (ostium secundum). (The foramen ovale arises later with the elongation of the septum secundum). left atrium- entrance of the L and R pulmonary veins and the auricle.
	D7: R atrium with R venous valve. R ventricle close to origin of pulmonary trunk. L.ventricular wall and three semilunar valves of aortic ostium.
	D6: Superior vena cava. Ascending aorta with transverse pericardial sinus behind. Semilunar valve at origin of pulmonary trunk. L. atrium and auricle. Thoracic aorta.
	D5: Superior vena cava. Ascending arch of aorta. Pulmonary trunk with the other two semilunar valves. Sinus above one valve and branching of pulmonary trunk into L and R pulmonary arteries.
	D4: Ascending aorta. Pulmonary trunk and arteries. Thoracic aorta. Oesophagus. Bronchi. Note azygos vein on right, and precursor of hemiazygos vein on left side. (Image excerpt different scale from previous images)
	D3: Ascending aorta attached cranial to transverse pericardial sinus. Superior vena cava expanding into R jugular vein. Trachea (bifurcation). Oesophagus. Azygos (R) and hemiazygos (L) veins.
	D2: Aortic arch. L jugular lymph sac lying laterally with hemiazygos joining it. Trachea. Oesophagus. Draining of azygos vein into R jugular vein.
	Dl: Aortic arch. Thymus (retrosternal). Trachea. Oesophagus. Large L and R jugular veins.
	C7: L brachiocephalic vein (transverse anastomosis of L, R jugular veins). L common carotid artery. Brachiocephalic trunk.
	C6: L and R common carotid arteries. L and R internal jugular veins.