Question

1. Compare and contrast the images of the left and right sides of the dissected heart. What is one similarity and what is one difference in the muscle tissue?

2. What is the difference between the structure of the atrioventricular valves and the semilunar valves? What is the function of each type of valve?

3. Where are the papillary muscles of the heart, and what do they look like?

Answer 1

1) From an image of a dissected heart, the follwing can be compared and contrasted:

• Ventricles have thicker wall than atria, in which the wall of the left ventricle is thicker than that of the right ventricle.
• The sinus node or the SA node and the AV node can only be seen in the right side of the heart.
• Both sides of the heart have chordae tendineae, also known as the heart strings. They are cord like tendons that connect the papillary muscles to the tricuspid valve and the bicuspid valve in the right and left ventricles of the heart respectively.
• The shape of the left ventricle is longer and more conical than the right with a slightly larger cavity whereas the right ventricle is triangular in shape.