Muscle function and antagonistic muscle pairs

In a nutshell

The muscular system works together with the skeletal system to enable the body to move. Muscles are attached to bones via tendons. Antagonistic muscles work in pairs by contracting and relaxing to allow movement of the joints in the body.

Muscles

Definition

A muscle is a group of muscle tissues formed from specialised muscle cells. Muscles contract to produce a force which enables the bones to move.

Types of muscles

There are three different types of muscle.

Skeletal muscle	Muscle attached to bones. When it contracts, it enables the bones to move and the joints to bend.
Cardiac muscle	Muscle of the heart. It enables blood to be pumped around the body.
Smooth muscle	Found in the internal organs and blood vessels. It is also known as involuntary muscle.

Curiosity: There are around $640$ muscles in the human body!

Tendons

Skeletal muscles are not directly connected to bones but are attached to them via tendons. Tendons are strong, tough bands. Tendons allow muscles to pull on the bones to help with movement.

Science; Human skeleton and muscles; KS3 Year 7; Muscle function and antagonistic muscle pairs — 1. Bone, 2. Muscle, 3. Tendon

Antagonistic muscles

Antagonistic muscles are a pair of muscles which act on a joint in opposite ways. One muscle contracts and shortens, whilst the other relaxes and returns to its original length. This enables you to move your joints forwards and backwards.

Example

Some antagonistic muscles include the biceps and triceps muscles in the arm, as well as the hamstrings and quadriceps muscles in the legs.