Download 113915_Heart_Disection

Name.
Directions:
Per.
Heart Dissection
Today we will be looking at a whole heart and a cross section of a heart. Due to limited numbers
of hearts, we will be working in fairly large groups. Please make sure that you share. If you are
not interested in touching or working with the heart, please have a group member report the
observations to you.
Whole Heart:
1. Please take a look at the heart. Please try and orientate the heart in to an anatomically
correct position. You can tell it is in the correct position because the apex of the heart
will point down and the base of the heart will be upwards. From there try to locate the
left side and right side by feel and look. (you may need Mr. McDonald’s help)
2. Now please feel the left side of the heart compared to the right side of the heart. Is
there a difference?
3. Next look at the base of the heart. The ones with the tubes coming out of the top. Please
identify each of the tubes coming out of the top. You can do this by the following.
a. You can stick your finger into the tubes,
i. If your finger enters the upper right side of the heart, you are reaching
through the vena cava.
1. Extend your finger and you can push it through the tricuspid valve into
the right ventricle
2. Then you can try to reach up through the pulmonary artery
ii. If your finger is in the lower right side of the heart, you are reaching
through the pulmonary artery.
iii. If your finger enters the lower left side of the heart, you are reaching
through the aorta and are righting in the left ventricle.
iv. If your finger enters the upper left side of the heart, you are reaching
through the pulmonary vein into left atrium.
Cross section of the heart:
1. Please have Mr. McDonald’s help cutting the heart in half.
2. Then please re-trace the blood vessels. (use the patter from above and the visual
reference to confirm which blood vessel is which and where it is heading.
3. Please look for all the heart valves.
a. You should be able to find at least
i. Tricuspid valve
ii. Bicuspid valve
4. Please compare the left side of the heart compared to the right side of the heart. Pinch
the ventricle walls and atrium walls of the heart. Is there a difference between the left
and right side of the heart? Why is there a difference?
5. Similar to the question above. Locate the aorta and the vena cava. Pinch these blood
vessels between your fingers. Is there a difference between the aorta artery and the
vena cava vein? Why is there the difference?
Analysis Questions
1. How can you be sure that your heart is orientated to an anatomical correct positioning?
2. How many chambers are found in the mammalian heart? List these chambers.
3. Which chambers are the pumping chambers of the heart?
4. Which chambers are the receiving chambers of the heart?
7. How do the walls of the atria compare with the walls of the ventricles and why are they different?
8. What is the purpose of heart valves?
9. Vessels that carry blood away from the heart are called __________, while __________ carry blood toward the
heart.
Extra credit. The Left Pulmonary Artery can also be called your Left Coronary Artery. What would happen if this
was blocked by a blood clot?