The bulbus cordis (the bulb of the heart) is a part of the developing heart that lies ventral to the

primitive ventricle The primitive ventricle or embryonic ventricle of the developing heart, together with the bulbus cordis that lies in front of it, gives rise to the left and right ventricles. The primitive ventricle provides the trabeculated parts of the walls, a ...

after the

heart The heart is a muscular organ in most animals. This organ pumps blood through the blood vessels of the circulatory system. The pumped blood carries oxygen and nutrients to the body, while carrying metabolic waste such as carbon dioxide to t ...

assumes its S-shaped form. The superior end of the bulbus cordis is also called the conotruncus.

Structure

In the early tubular heart, the bulbus cordis is the major outflow pathway. It receives blood from the

, and passes it to the

truncus arteriosus The truncus arteriosus is a structure that is present during embryonic development. It is an arterial trunk that originates from both ventricles of the heart that later divides into the aorta and the pulmonary trunk. Structure The truncus arterio ...

. After heart looping, it is located slightly to the left of the ventricle.

Development

The early bulbus cordis is formed by the fifth week of

development Development or developing may refer to: Arts *Development hell, when a project is stuck in development *Filmmaking, development phase, including finance and budgeting *Development (music), the process thematic material is reshaped * Photograph ...

. The truncus arteriosus is derived from it later. 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 A ventricle is one of two large chambers toward the bottom of the heart that collect and expel blood towards the peripheral beds within the body and lungs. The blood pumped by a ventricle is supplied by an atrium, an adjacent chamber in the uppe ...

, while the junction of the bulbus with the

is brought directly ventral to and applied to the

atrial canal The proper development of the atrioventricular canal into its prospective components (The heart septum and associated Heart valve, valves) to create a clear division between the four compartments of the heart and ensure proper blood movement throug ...

. By the upgrowth of the

ventricular septum The interventricular septum (IVS, or ventricular septum, or during development septum inferius) is the stout wall separating the ventricles, the lower chambers of the heart, from one another. The ventricular septum is directed obliquely backwar ...

the bulbus cordis is separated from the

left ventricle A ventricle is one of two large chambers toward the bottom of the heart that collect and expel blood towards the peripheral beds within the body and lungs. The blood pumped by a ventricle is supplied by an atrium, an adjacent chamber in the uppe ...

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

infundibulum An infundibulum (Latin for ''funnel''; plural, ''infundibula'') is a funnel-shaped cavity or organ. Anatomy * Brain: the pituitary stalk, also known as the ''infundibulum'' and ''infundibular stalk'', is the connection between the hypothalamus an ...

. Together, the bulbus cordis and the primitive ventricle give rise to the ventricles of the formed heart.

Other animals

The bulbus cordis is shared in the development of many animals, including

frogs A frog is any member of a diverse and largely carnivorous group of short-bodied, tailless amphibians composing the order Anura (ανοὐρά, literally ''without tail'' in Ancient Greek). The oldest fossil "proto-frog" '' Triadobatrachus'' is ...

and

fish Fish are aquatic, craniate, gill-bearing animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish as well as various extinct related groups. Approximately 95% of ...

Additional images

File:Gray460.png, Head of chick embryo of about thirty-eight hours’ incubation, viewed from the ventral surface. X 26 File:Gray461.png, Diagram to illustrate the simple tubular condition of the heart. File:Gray462.png, Heart of human embryo of about fourteen days. File:Gray977.png, Human embryo about fifteen days old. Brain and heart represented from right side. Digestive tube and yolk sac in median section.

References

External links

* * * * {{Anatomy-stub Embryology of cardiovascular system