Muhlenberg college

FIGURE 1
Left view of a three-day-old chicken embryo. The front of the head is at the top of the picture – you can see the left nostril right above the right ventricle (RV)! The heart is looping so the atrium (A) has moved anterior to the ventricle. The conotruncus (CT), which is attached and anterior to the ventricle, is hidden in the shadow of the head.
 
 

FIGURE 2
A front/ventral view of a two day old chicken embryo. The heart has just begun to loop, moving the atrium (A) into a more anterior position. The head, actually the nose, is hanging right over the conotruncus (CT). Bar = 95 um.
 

FIGURE 3
Three day old chicken heart, seen from a right/front view. The atrium (A) has begun to differentiate into the left and right chambers, as evidence by the fact that the left atrium is bulging outwards. Bar = 100 um.
 
 
 

FIGURE 4
Two to three day old chicken heart which has had part of its atrial and ventricular wall ripped off (on purpose!). You can see the thick myocardium in the left ventricle (LV) and the early development of the trabeculae (T). In some areas you can also see the thin endocardium and epicardium. Also, the cardiac jelly between the atrium (A) and left ventricle (LV) may be visible.
Bar = 100um.

FIGURE 5
This two to three day old chicken heart had the ventral half of the ventricle removed. The early trabeculae are visible (arrows) and the epicardium at the top of the atrium and ventricle is visible.