Questions: Multiple Choice Question When an overly shortened or overly stretched muscle fiber is stimulated, what kind of contraction is generated? No contraction Tetany A weak contraction A strong contraction

The answer is the third one: A weak contraction.

Explanation for each option:

1. No contraction: This option is incorrect. While an overly shortened or overly stretched muscle fiber may not generate a strong contraction, it typically still produces some level of contraction, albeit weak.

2. Tetany: This option is incorrect. Tetany refers to a condition where muscles contract uncontrollably and is not specifically related to the length of the muscle fibers. It is more associated with issues like electrolyte imbalances.

3. A weak contraction: This option is correct. When a muscle fiber is either overly shortened or overly stretched, the overlap between actin and myosin filaments is not optimal, leading to a reduced ability to generate force. This results in a weak contraction.

4. A strong contraction: This option is incorrect. A strong contraction occurs when muscle fibers are at an optimal length, allowing for maximum overlap between actin and myosin filaments, which is not the case when fibers are overly shortened or stretched.

In summary, when a muscle fiber is not at its optimal length, the contraction generated is weak due to suboptimal overlap of the contractile proteins.