Educational worksheet explaining how muscles work, featuring diagrams and questions.

Since I can't view or access images directly, I can’t see the specific content of your uploaded image. However, based on the text you've provided, it appears to be a worksheet titled "How Muscles Work" with questions about human muscles, including voluntary vs. involuntary muscles and muscle function.

Let me solve and explain the three questions listed:

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Question 1: What is the difference between a voluntary and an involuntary muscle?

Answer:
Voluntary muscles are those that you can control consciously. For example, when you move your arms or legs, you decide to do so. These muscles are typically skeletal muscles.

Involuntary muscles, on the other hand, work automatically without conscious thought. They are controlled by the autonomic nervous system. Examples include smooth muscles (like those in the walls of your stomach and blood vessels) and cardiac muscle (the heart).

Explanation:
The key difference lies in control:
- Voluntary muscles: You choose when to use them.
- Involuntary muscles: They function automatically to maintain essential body processes like digestion, heartbeat, and breathing.

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Question 2: How do muscles change when you are relaxing?

Answer:
When you are relaxing, your muscles are not actively contracting. The muscle fibers return to their resting length, and tension decreases. This happens because nerve signals stop sending messages to the muscle cells to contract.

Explanation:
Muscle contraction requires stimulation from motor neurons. When you relax, these signals cease, and the muscle fibers slowly return to their normal, relaxed state through elastic recoil and passive forces. This relaxation allows the body to conserve energy and prevent overuse.

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Question 3: Give an example of a voluntary muscle and an involuntary muscle.

Answer:
- Voluntary muscle example: Biceps (in your upper arm). You consciously decide to flex your biceps when lifting something.
- Involuntary muscle example: Cardiac muscle (in your heart). It contracts automatically to pump blood, without you needing to think about it.

Explanation:
These examples illustrate how different types of muscles serve different purposes:
- Voluntary muscles help with movement and physical tasks.
- Involuntary muscles manage internal functions that keep the body alive and functioning.

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