Question

Flexor and extensor muscles are ___.

• A. antagonistic muscles
• B. complementary muscles
• C. involuntary muscles
• D. voluntary muscles

Answer 1

The correct option is A

antagonistic muscles

A structure which has been moved by a muscle cannot return to its original position without the action of another muscle. Such muscles causing opposing movements are called antagonistic muscles. Antagonist and agonist muscles often occur in pairs, called antagonistic pairs. As one muscle contracts, the other relaxes. An example of an antagonistic pair is the biceps and triceps; the triceps relaxes while the biceps contracts to lift the arm.