Which is not true about chordae tendineae?

Options

A. (a) They are stripes of muscular tissue
B. (b) They are attached to valves
C. (c) They are attached to papillary muscles
D. (d) They prevent collapsing of valves into atria

Answer

### Step-by-Step Solution:

1. **Understanding Chordae Tendineae**: Chordae tendineae are fibrous cords in the heart that connect the papillary muscles to the atrioventricular valves (the mitral and tricuspid valves). They play a crucial role in the functioning of these valves.

2. **Identifying the Options**: The question asks which statement about chordae tendineae is not true. We need to evaluate each option provided.

3. **Evaluating the Statements**:
- **Option A**: "They are stripes of muscular tissue."
- This statement is incorrect because chordae tendineae are made of connective tissue, not muscular tissue.
- **Option B**: "They are attached to valves."
- This statement is correct as they connect to the mitral and tricuspid valves.
- **Option C**: "They are attached to papillary muscles."
- This statement is also correct since chordae tendineae connect the papillary muscles to the valves.
- **Option D**: "They prevent collapsing of valves into atria."
- This statement is correct as they help maintain the position of the valves during heart contractions.

4. **Conclusion**: The only incorrect statement among the options is Option A, which claims that chordae tendineae are stripes of muscular tissue.

### Final Answer:
The statement that is not true about chordae tendineae is **Option A: They are stripes of muscular tissue.**

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