The bulbus cordis lies ventral to the primitive ventricle

Primitive ventricle

The embryonic ventricle or primitive ventricle of the developing heart gives rise to the trabeculated parts of the left and right ventricles...

 after the developing heart

Heart

The heart is a myogenic muscular organ found in all animals with a circulatory system , that is responsible for pumping blood throughout the blood vessels by repeated, rhythmic contractions...

 assumes its S-shaped form. Together, the bulbus cordis and the primitive ventricle give rise to the ventricle

Ventricle (heart)

In the heart, a ventricle is one of two large chambers that collect and expel blood received from an atrium towards the peripheral beds within the body and lungs. The Atria primes the Pump...

 of the formed heart

Heart

The heart is a myogenic muscular organ found in all animals with a circulatory system , that is responsible for pumping blood throughout the blood vessels by repeated, rhythmic contractions...

.

The adjacent walls of the bulbus cordis and ventricle approximate, fuse, and finally disappear, and the bulbus cordis now communicates freely with the right ventricle

Right ventricle

The right ventricle is one of four chambers in the human heart. It receives deoxygenated blood from the right atrium via the tricuspid valve, and pumps it into the pulmonary artery via the pulmonary valve and pulmonary trunk....

, while the junction of the bulbus with the truncus arteriosus

Truncus arteriosus (embryology)

The truncus arteriosus and bulbus cordis are divided by the aorticopulmonary septum. The truncus arteriosus gives rise to the ascending aorta and the pulmonary trunk. The caudal end of the bulbus cordis gives rise to the smooth parts of the left and right ventricles...

 is brought directly ventral to and applied to the atrial canal

Atrial canal

In the developing heart, the constriction between the atrium and ventricle constitutes the atrioventricular canal or atrial canal, and indicates the site of the future atrioventricular valves.-External links:*...

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By the upgrowth of the ventricular septum the bulbus cordis is in great measure separated from the left ventricle

Left ventricle

The left ventricle is one of four chambers in the human heart. It receives oxygenated blood from the left atrium via the mitral valve, and pumps it into the aorta via the aortic valve.-Shape:...

, but remains an integral part of the right ventricle, of which it forms the infundibulum

Conus arteriosus

The conus arteriosus is a conical pouch formed from the upper and left angle of the right ventricle in the chordate heart, from which the pulmonary trunk arises....

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