Antagonistic Muscles and Movement

Flashcards covering antagonistic muscle pairs, arm anatomy, and joint mechanics based on lecture notes.

How do antagonistic muscle pairs work together?

When one muscle contracts, the other muscle relaxes.

What type of muscle pair are the biceps and triceps?

They are an antagonistic pair of muscles.

How do the biceps and triceps move the forearm?

They work oppositely to move the forearm.

What force action can muscles perform, and what can they not do?

Muscles can only contract (pull); they cannot push.

What happens to the biceps when it contracts?

It shortens.

What happens to the triceps when the biceps contracts?

The triceps relaxes.

What joint action occurs when the biceps contracts and shortens?

It flexes the elbow, bringing the forearm upwards.

In which direction does the forearm move when the elbow flexes?

Upwards.

What effect does extending the elbow have on the forearm?

It moves the forearm downwards / straightens the arm.

How are muscles attached to bones?

Muscles are attached to bones by tendons.

Where does movement occur in the lever mechanism of the arm?

Around a joint.

What role do bones play during movement around a joint?

Bones act as levers.

Which bone of the upper arm is labeled in the diagram?

Humerus.

Which two forearm bones are labeled in the diagram?

Radius and Ulna.

Why are pairs of muscles needed to move the forearm up and down?

Because muscles can only contract (pull) and cannot push.

Which muscle contracts to flex the elbow?

The biceps.

What happens to the biceps when the elbow extends?

The biceps relaxes.

What happens to the triceps when the arm straightens?

The triceps contracts and shortens.

What structures attach the biceps and triceps to the bones?

Tendons.

What term describes muscles that work oppositely to produce movement?

Antagonistic muscles.