Question

Question 2

(06.01 MC)

Why do skeletal muscles work in pairs?

One tightens and the other relaxes to make the bones move.

Multiple muscles have to tighten to make joints move.

They cancel each other out.

Bones are resistant to movement.

Answer 1

Muscles work in pairs to allow for movement at the joints of the body. When one muscle contracts, the other muscle relaxes or elongates.

Step-by-step explanation:

Muscles work in pairs because muscles can only contract and cannot actively extend. To move bones in opposite directions, pairs of muscles work in opposition. When one muscle in the pair contracts, the other muscle relaxes or elongates. This allows for movement at the joints of the body.

For example, the biceps and triceps muscles in the upper arm work as a pair. The biceps muscle contracts to bend the elbow joint, while the triceps muscle contracts to straighten the elbow joint.