The Muscles of
Your Body
Vocabulary
Read the vocabulary terms to understand the reading better.
Achilles Tendon
The Achilles tendon is a strong tendon at the back of the heel that joins the calf muscle to the heel bone.
Diaphragm
The diaphragm is a separator in the body that is made up of muscle and connective tissue and that separates the chest cavity from the abdominal cavity.
Joints
Joints are the places where two or more bones meet and where cartilage separates the bones and allows body parts to move.
Muscles
Muscles are body tissues made up of long cells that contract, or shorten, to make body parts move.
Skeletal Muscles
Skeletal muscles are muscles that are connected to a bone to move parts of the skeleton.
Tendons
Tendons are bands of tough, non-stretchy tissue that connect muscles to bones.
Your bones and joints need muscles to help them move. There are about 660 muscles in your body. Skeletal muscles shape the body and hold it upright.
Another important muscle is your diaphragm. It is a dome-shaped muscle below your lungs. This muscle squeezes your lungs when you breathe out. Muscles in your intestines work without you thinking about them.

Pulling in Pairs
Muscles can only pull bones and joints, they cannot push them. So muscles often work in pairs. For example, the biceps muscle bends your arm. Your triceps muscle straightens your arm. It does this by pulling on the back of your elbow. Touch your arm and you will feel them working.

Tough Tendons
Each muscle narrows into a cord at the end. This is dense, tough tissue known as a tendon. Tendons are attached to bones. When the muscle contracts, the tendon pulls on the bone.
The jaw muscle is the strongest muscle in your body. Your tongue is a muscle that helps you communicate and eat. It takes about 16 muscles to smile.

Touch a Tendon
You can feel your Achilles tendon. It is one of the largest tendons in your body. Pinch your lower leg, just above your heel. The tendon feels hard like a bone. But when you press it, it bends slightly. The Achilles tendon joins the muscles in your calf to your heel. This is so you can pull up your foot when you walk.

To learn more about the muscles in your body, watch the video by Smile and Learn on YouTube.
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