This portion of Figure 10-6A from Developmental Stages in Human Embryos shows an outline of the myocardial mantle and endocardial tube at the plexiform phase of cardiac development.
Label Key:
* - Left Interventricular Sulcus
Ao.1 - Aortic Arch 1
C-T - Conotruncus
RV - Right Ventricle
LV - Left Ventricle
RA - Right Atrium
LA - Left Atrium
Fig. 10-6A. O'Rahilly and Müller, 1987.
Keywords: aortic arch 1, conotruncus, endocardial tube, interventricular sulcus, left atrium, left ventricle, myocardial mantle, plexiform phase of cardiac development, right atrium, right ventricle
Source: The Virtual Human Embryo.