endocardial heart tube

endocardial heart tube

connection at which two tubes come together and fuse in an embryo's midthoracic region to form the primordial cardiac (or heart) tube, which is the primordium of the heart.

en·do·car·di·al heart tube

(en'dō-kahr'dē-ăl hahrt tūb)
The two endothelial tubes that meet in the midthoracic region of the embryo and fuse to form the primordial cardiac or heart tube, the primordium of the heart.