This image shows a ventral view of the heart of a preserved bullfrog. The heart of all amphibians contains three chambers – a muscular ventricle and two thin-walled atria. Although there is some mixing of oxygenated and de-oxygenated blood, this problem is reduced considerably due to the presence of a spiral valve that shunts oxygenated blood to the body and poorly oxygenated blood to the lungs and skin. For a more detailed view of the major structures and vessels of the heart, see the images of the frog heart model.

On the image above observe the large ventricle (1), the left atrium (2) and right atrium (3). Note that the conus arteriosus (4) coming off the ventricle divides into two great vessels, the left truncus arteriosus (5) and right truncus arteriosus (6). Each truncus arteriosus give rise in turn to three vessels called the aortic arches, which consist of the common carotid artery (which goes to the head region), the pulmocutaneous artery (which goes to the lungs and skin) and the systemic arch (which goes to the rest of the body).  Also note that two of the three lobes of the liver (7), which is the largest organ in the body cavity, are shown on the image.