The contraction of muscle of shortest duration is seen in

Options

A. Jaws
B. Eyelids
C. Heart
D. Intestine

Answer

**Step-by-Step Solution:**

1. **Identify the Question**: The question asks for the muscle that has the shortest duration of contraction.

2. **Understand Muscle Types**: There are different types of muscles in the human body: voluntary muscles (which can be controlled consciously) and involuntary muscles (which function automatically).

3. **Consider the Options**: The options provided include jaws, eyelids, heart, and intestines. We need to evaluate each option to determine which muscle has the shortest contraction time.

4. **Evaluate the Jaws**: The jaws are voluntary muscles. They can be contracted and relaxed at will, but they do not have the shortest contraction duration. Therefore, this option is incorrect.

5. **Evaluate the Eyelids**: The eyelids are controlled by the orbicularis oculi muscle, which is known to be the fastest reacting muscle in the human body. It can contract in less than 0.01 seconds, making it the muscle with the shortest duration of contraction. This option is correct.

6. **Evaluate the Heart**: The heart muscle beats approximately 72 times per minute. While it is an important muscle, its contraction duration is not the shortest compared to the eyelids. Thus, this option is incorrect.

7. **Evaluate the Intestines**: The intestinal movements, known as peristalsis, occur continuously throughout the day. This is not a rapid contraction, making this option incorrect as well.

8. **Conclusion**: After evaluating all options, the muscle with the shortest duration of contraction is the eyelids, specifically the orbicularis oculi muscle.

**Final Answer**: The contraction of muscle of shortest duration is seen in the eyelids.

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