Muscle

High school (ages 12+)
Human Body

Name:

Date:

Step 1 · Read the article

Open the article and read it at the level above. Then answer the questions below in your own words.

https://smallwhale.org/articles/muscle

Write what each word means, using the article.

Do not copy the article. Write two things you learned, the way you would explain them to a friend.

Answers below are taken from the article’s stored facts, so they match what the student read.

1. What is the number of muscles?Approximately 650 skeletal muscles, plus smooth and cardiac muscle
2. What is the primary mechanism?Sliding filament theory involving actin and myosin protein interactions
3. What are the three main types of muscles?There are skeletal muscles that attach to bones and let us move on purpose, smooth muscles that work inside organs like the stomach, and cardiac muscle that keeps the heart beating.
4. How do muscles contract to make us move?A nerve sends a signal to a muscle, releasing a chemical that lets calcium inside the muscle. The calcium lets tiny parts called actin and myosin slide past each other, shortening the muscle and creating a pull.

Sarcomere: The basic contractile unit of striated muscle, composed of actin and myosin filaments.
Neuromuscular Junction: The specialized synapse where a motor neuron communicates with a muscle fiber.
Sarcopenia: Age-related loss of muscle mass, strength, and function.