The free edges of cuspid valves are attached to the papillary muscles of the heart by fibres are called ___________.

Options

A. chordae tendinae
B. columnae carneae
C. connecting fibres
D. autorhythmic fibres

Answer

**Step-by-Step Solution:**

1. **Understanding the Question:** The question asks for the name of the fibers that attach the free edges of cuspid (AV) valves to the papillary muscles in the heart.

2. **Identifying Cuspid Valves:** The cuspid valves, also known as atrioventricular (AV) valves, include the tricuspid valve (right side) and the mitral valve (left side). These valves prevent backflow of blood from the ventricles into the atria during contraction.

3. **Role of Papillary Muscles:** Papillary muscles are located in the ventricles of the heart and are responsible for holding the cuspid valves in place. They contract to prevent the valves from inverting or prolapsing when the ventricles contract.

4. **The Connecting Fibers:** The fibers that connect the free edges of the cuspid valves to the papillary muscles are crucial for the proper functioning of the heart. These fibers ensure that the valves close tightly and do not allow blood to flow backward.

5. **Identifying the Correct Term:** The specific name for these fibers is "Chordae tendineae." They are often referred to as "heart strings" due to their appearance and function.

6. **Conclusion:** Therefore, the answer to the question is that the free edges of cuspid valves are attached to the papillary muscles of the heart by fibers called **Chordae tendineae**.

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