Section 19.5: Development of the Heart - Terms

Mesoderm

One of the three primary germ layers in the embryo that gives rise to the heart and other tissues and organs.

Cardiogenic area

The region near the head of the embryo where the heart begins to develop.

Cardiogenic cords

Strands that form in the cardiogenic area and develop into endocardial tubes.

Endocardial tubes

Structures formed from the cardiogenic cords that fuse to create the primitive heart tube.

Primitive heart tube

A single tube formed from the fusion of endocardial tubes, which develops into the heart.

Truncus arteriosus

The region of the primitive heart tube that develops into the ascending aorta and pulmonary trunk.

Bulbus cordis

The region of the primitive heart tube that develops into the right ventricle.

Primitive ventricle

The region of the primitive heart tube that forms the left ventricle.

Primitive atrium

The region of the primitive heart tube that becomes the anterior portions of both the right and left atria and the auricles.

Sinus venosus

The region of the primitive heart tube that develops into the posterior portion of the right atrium, the SA node, and the coronary sinus.

Interatrial septum

A structure that partitions the atria during heart development.

Interventricular septum

A structure that partitions the ventricles during heart development.

Atrioventricular septum

A structure that partitions the atria and ventricles during heart development.

Atrioventricular valves

Valves that form between weeks five and eight of heart development.

Semilunar valves

Valves that form between weeks five and nine of heart development.