Below are autopsy pictures of rat hearts.
This heart looks very normal, except that it is twisted a little clockwise. But it shows a good view of the right atrium at the top left of the heart in the picture, and the left atrium at the bottom left, which would normally be at the top right-hand side of the heart in a picture.
This is a normal appearing heart showing a good view of the right and left atria (plural of atrium) on either side at the top of the heart.
This picture shows a massively enlarged right atrium.
This heart is showing a fairly typical abnormality: right-side enlargement. This is caused by high blood pressure in the lungs that makes it difficult for the heart to pump blood through them, which results in the blood backing up in the right side of the heart. The right ventricle, which is on the left side of the heart in the picture, is blown up like a balloon, and the right atrium, on the left in the picture, is slightly larger than normal.
This heart also shows a moderate enlargement of the right ventricle, but the right atrium is not as enlarged.
This heart shows a grossly enlarged right atrium, which is also lighter than usual, maybe because it is thickened, and a moderately enlarged right ventricle.
This heart has a massively enlarged and unusually purple right ventricle.
This is the cross-section of a normal rat heart. This is the cross-section of a heart with hypertrophic cardiomypathy, where the walls of the left ventricle become thickened and the left ventricle itself is reduced in size. Hypertrophic cardiomyopathy is the most common form of heart failure in rats.
This picture shows the cross-section of a heart with an enlarged right ventricle (full of clotted blood) on the left and hypertrophic changes of the left ventricle.
Although this picture is dark, it shows a heart with massively thickened walls of the left ventricle, and a small narrow left ventricle, a bad case of hypertrophic cardiomyopathy.
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