Heart Dissection

  

External Anatomy

The heart seems to be a maroon and dark purple color, but there is a huge color differential on different parts of the heart. It weighs less than a pound, it is also uneasy to control due to its slippery conditions.  When viewed from the front, the heart is triangular. The base of the heart has a broader top end, from which the vessels enter and leave the heart. The heart narrows down to a rounded point. It was easy to spot the four chambers of the heart, the right and left atria and ventricles. The aorta and pulmonary trunk seemed to be flappy. The inferior and superior vena cava was difficult to spot because it seemed to be much smaller and thinner than expected.

Internal Anatomy

The internal anatomy was awfully sickening. The left ventricle wall seemed much thicker than the right ventricle wall. It was noticeable different because I was able to feel the thick layer of muscle covering the left ventricle while the right ventricle seemed very thin. The semi-lunar valve, aortic valve, left and right valves seemed all similar. They were all glutinous and thin. They felt like pieces of gum, but stronger and a lot more durable.

Questions:

1. What was the most surprising thing about dissecting the heart?  Describe what your expectations were and if they were met.

The most surprising thing about dissecting the heart was being able to see how condensed the parts of the heart actually are. Even though the heart is very compact and much smaller in size then I imagined, it amazed me how something that is comparable to the size of my fist can manage to pump blood throughout my entire body.

2. Why are the atria and ventricles so different (compare their structure to their function)?

The atria are the upper chamber of the heart and the ventricles are the lower chamber. The Atria receive deoxygenated blood while the ventricles receive blood from the atria and force it out to the aorta or the pulmonary artery. The atria have thinner walls due to low blood pressure and the ventricles have thick walls due to high blood pressure.

3. Why is the left ventricle more muscular than the right?

The reason the left ventricle is more muscular than the right ventricle is because the right and left ventricles both have different jobs. The right ventricles job is to send deoxygenated blood to the lungs so the lungs can collect the CO2 and give away 02 to the blood. Meanwhile the left ventricle has to send oxygenated blood throughout our entire bodies which requires a lot more strength, therefore it is more muscular because the left ventricle is doing a lot more work than the right which causes it to enlarge due to its amount of strength building up.

4. What are functions of the heart valves?  Describe how the structure of the valves relates to their function (including chordae tendinae).

When the left ventricle relaxes, the aortic valve closes and the mitral valve opens, to allow blood to flow from the left atrium into the left ventricle. The left atrium contracts, allowing even more blood to flow into the left ventricle, When the left ventricle contracts again, the mitral valve closes and the aortic valve opens, so blood flows into the aorta.