Muscles

Muscles are important tissues in the human body that enable movement, maintain posture, and circulate blood and other substances throughout the body. There are three types of muscles: skeletal, smooth, and cardiac.

Skeletal Muscles

Skeletal muscles are attached to the bones and are responsible for voluntary movements such as walking, running, and lifting objects. These muscles work in pairs - when one muscle contracts (shortens), the other relaxes (lengthens) to produce movement.

Smooth Muscles

Smooth muscles are found in the walls of internal organs, blood vessels, and the digestive system. They are responsible for involuntary movements such as peristalsis (the movement of food through the digestive system) and regulating the diameter of blood vessels.

Cardiac Muscle

Cardiac muscle is found in the heart and is responsible for pumping blood throughout the body. It is also an involuntary muscle, meaning it contracts without conscious effort.

Study Guide

1. What are the three types of muscles?
2. Describe the function of skeletal muscles.
3. Where are smooth muscles found, and what are their functions?
4. Which type of muscle is found in the heart, and what is its function?
5. Explain the difference between voluntary and involuntary muscles.

[Muscles] Related Worksheets and Study Guides:

• Bones, muscles, and skinScience • Eighth Grade
• Moving and Controlling the BodyScience • Sixth Grade