What role do the chordae tendineae play in the functioning of the heart valves?
Solution
Correct Answer: Option A
The chordae tendineae play a crucial role in the proper functioning of the heart valves, particularly the atrioventricular valves (the mitral and tricuspid valves). These are thin, strong, fibrous cords that connect the leaflets of the valves to the papillary muscles located on the inner walls of the ventricles.
When the ventricles contract during systole, the papillary muscles also contract, which pulls on the chordae tendineae. This action prevents the valve leaflets from prolapsing or inverting into the atria, thereby ensuring that the valves close securely. As a result, the chordae tendineae help prevent the backflow of blood from the ventricles to the atria, maintaining one-way blood flow through the heart.
It is important to note that the chordae tendineae do not generate electrical impulses (Option 2), nor do they facilitate blood flow through coronary arteries (Option 3), or regulate the opening of semilunar valves (Option 4). The semilunar valves (pulmonary and aortic valves) operate differently and are not supported by chordae tendineae.
In summary:
- Chordae tendineae anchor the atrioventricular valve leaflets to papillary muscles.
- They prevent valve prolapse during ventricular contraction.
- This ensures that blood flows in only one direction, preventing backflow into the atria.
Reference:
Gray's Anatomy, 41st Edition, Cardiovascular System, Heart Valves Chapter/Page 658-660
When the ventricles contract during systole, the papillary muscles also contract, which pulls on the chordae tendineae. This action prevents the valve leaflets from prolapsing or inverting into the atria, thereby ensuring that the valves close securely. As a result, the chordae tendineae help prevent the backflow of blood from the ventricles to the atria, maintaining one-way blood flow through the heart.
It is important to note that the chordae tendineae do not generate electrical impulses (Option 2), nor do they facilitate blood flow through coronary arteries (Option 3), or regulate the opening of semilunar valves (Option 4). The semilunar valves (pulmonary and aortic valves) operate differently and are not supported by chordae tendineae.
In summary:
- Chordae tendineae anchor the atrioventricular valve leaflets to papillary muscles.
- They prevent valve prolapse during ventricular contraction.
- This ensures that blood flows in only one direction, preventing backflow into the atria.
Reference:
Gray's Anatomy, 41st Edition, Cardiovascular System, Heart Valves Chapter/Page 658-660
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