Sheep Heart Dissection

1. The purpose of the pericardium is to surround and protect the heart. It has two layers- the outer pericardium and the inner peridcardium. The outer pericardium anchors the heart, prevents overstretching, and protects the heart. The inner pericardium has the partiel layer and the visceral layer- and in between that is the pericardial fluid that reduces friction in the heart.

2. Veins are used to carry blood to the heart from the tissues. They have thinner walls that arteries and have one way valves inside of them that block the back flow of blood. Arteries are elastic and contractile to expand when the heart contracts and recoil when it relaxes. Arteries carry blood from the heart to the tissues.

3. The auricle is similar is to an ear like shape, when blood floods into the area, it serves as holding extra blood for the heart, adding extra volume to the heart.

4. The atria seemed to have more fat around it, which may have been the auricle serving as an appendage to the atria, while the ventricles do not have auricles on their external surface.

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7. The chordae tenidae and papillary muscle serve as an anchor of the valves to the heart. This prevents the inversion of the valves with every contraction and relaxation.

8. The bicuspid valve is a dual flap valve. It is between the left atria and the left ventricle and is anchored to the endocardium by the chordae tenidae and papillary muscle that prevent the inversion of the valve.



9. The semi-lunar valves prevent arterial blood from entering the heart. They are two main ones in the heart - the pulmonary semi-lunar valve. and the aortic semi-lunar valves.

10a.  If there was a blockage in the right side of the heart, that means that there would be back flow into the superior and inferior vena cava. The inferior vena cava would be most affected due to gravity, and since it is an artery, it has no one way valves to prevent this back flow either. Gravity would then make the blood flow down to the lower extremities, causing feet and ankles to swell.

10b. The left side of the heart is responsible for pumping oxygenated blood to the body. If there was a blockage on the left side, I would expect to see back flow into the lungs, since blood enters the left side of the body through the pulmonary veins. There would likely be some heaviness in the chest, as well as difficulty breathing from the blood pooling in the lungs.

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12. The left side of the heart deals with oxygenated blood while the right side deals with oxygenated blood. The left side of the heart is also a bit thicker, especially in the left ventricle because it needs to be strong enough to deliver blood up and over the aorta and to the entire body. The right ventricle on the other hand has a thinner myocardium wall since it only needs to deliver blood to the lungs.

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