my heart only beats for you

Today in Physiology, we had the opportunity of dissecting cow hearts. The cows were slaughtered at four in the morning and we got to handle them at one in the afternoon. They were a bit stinky and gross, but after taking a few pictures, I dove right in with the scalpel and sliced that bad boy up. We started off by cutting the apex of the heart off. Located in the apex are the inferior vena cava and the left and right ventricles.

Slicing of the apex.

Left ventricle is on the left
Right ventricle is on the right.

And then I put the camera down. But, the heart was about six or seven pounds in weight and maybe thirteen inches in circumference, at its widest point. Lengthwise is was about a foot and a half. These things were huge!!! We then sliced the right ventricle open and found a blood clot the size of a silver dollar resting in the right atrium. Just below the right atrium was the rest of the right ventricle and the heartstrings. The heart strings are so tough that you can hook your finger underneath them and hold the entire heart by the strings. Just below the heartstrings was the pulmonary muscle, smooth brown tissue that held the heartstrings in place. So gnarly. Libby, Megan, Colby and I proceeded to stick our fingers into every hole we could find; the aortic arch, pulmonary trunk, left and right pulmonary arteries and veins, the rubber band ball of the heart and the heart bone.
In a human, the heart is small enough to be encased in the pericardial sack and be just fine. However, in a cow, the heart is so large that it needs extra support to stay in one place. Fixed in the lower half of the aorta and in the left atrium was the heart bone. About three inches long, we broke out the scalpel and tried to pry it out. It took all of us pulling on it to finally loose it from the tissue.
Our heart was encased in a thick layer of fat. We concluded that our cow, named Harry, was an overweight cow with very very high cholesterol.

Thanks Harry the Cow
for lending us your most vital organ.