Heart Breaker

We dissected a heart this past valentines day, a bit ironic i know. In this lab, we had to measure some of the more...important parts of the heart. We measured the diameter of the Aorta, Pulmonary Trunk, right and left atrium, right and left ventricles, and the outer walls. We measured all of those things on 3 different species' hearts. There was the Sheep heart, Pig heart, and the Cow heart. Though the basic structure of these hearts were pretty much the same, the major difference in them came in the overall size of the parts we had to measure. For instance, the Sheep heart was no bigger than ones hand, where as the cow heart was massive! So you could conclude that it was easier to find things like the Aorta on the cow heart than the sheep heart. The reason for this extreme size difference in the hearts, could be contributed to the amount of blood that needs to be pumped into the body, so a cow needs to have more blood going through their body than a sheep needs to go through theirs. An interesting fact about the pig heart, is that it is about the same size as a human heart. Therefore the human and the pig need about the same amount of blood pushed throughout their bodies.

One of the questions that we were asked to find out by using the microscope and analyzing parts of the veins outer wall, and an arteries outer wall, was what is thicker, the wall of the veins or the walls of the arteries. The answer is the walls of the arteries, because they have more blood flowing through them at a faster rate than veins do. As for the Cardiac muscle (around the heart), it is a striated muscle, where as most other muscles are silky smooth. After viewing that, we went ahead and looked at a coronary artery with atherosclerosis, which is a kind of plaque that builds up in some arteries, which can then restrict the blood flow, and possibly cause a blood clot.

The sheep heart had the largest right side outer wall at 5 cm, and the pig heart has the largest left side outer wall coming in at 4 cm. In terms of overall size, the cow heart is the largest, yet in terms of the part, the cow heart is only the biggest in the left ventricle. I find that to be somewhat...odd.

brain dissection

We did a lab where we got to cut apart a brain and identify the parts that help to give the brain is funky looking form. For safety reasons we had to use rubber gloves, and an optional goggle accessory. We started off the lab by observing the Dura mater, or outer meanings. though not all the brains had them, the one that we had did. se we wound up cutting of this weird looking white layer from the outside of the brain. After that, we had to identify the cerebrum, where we saw the groves that are known as sulci. you should also see the ridges called gyri, which are pretty close to the medial longitudinal fissure, which separates the left and right hemispheres of the cerebral cortex. We then had a little bit to go and identify nearly every part of the brain. from the thalamus to the central canal, and from the spinal cord to the olfactory bulb.

We wound up getting to cut the brain horizontally. Which is the horizontal way to cut the brain, you just put it on its side, and cut through it. It leaves you with some pepperoni looking slices in your dissection tray. The odd clear stuff on the far left side of the picture is the Dura matter, which is a white "casing" that the brain happens to be in...and its pretty grodi.