Rat Heart Anatomical Photo Atlas
ATRIA DISSECTION:
Both Auricles and Atria Removed - Dorsal View
In the bottom picture, the Pulmonary Trunk has been cut before it splits into the 2 Pulmonary Arteries. The Left Coronary Artery can be seen originating from an ostium of an aortic valve cusp sinus - the sinus (*) is also filled with rubber in the aorta. Additionally, the researcher's gloves are visible in the lower left and right sections of the picture.

Closer Look From Above
