What muscle works in a pair with the biceps brachii?Multiple Choicethe triceps brachiithe trapeziusthe masseterthe pectoralis majorthe sartorius

Breakdown of the Problem

To answer the question, we need to identify which muscle works in opposition to the biceps brachii. The biceps brachii is responsible for flexing the elbow, so we are looking for a muscle that extends the elbow.

Relevant Concepts

• Biceps Brachii: A muscle that helps in the flexion of the elbow and supination of the forearm.
• Triceps Brachii: The muscle that extends the elbow and works in opposition to the biceps brachii.

Analysis and Detail

1. The biceps brachii and triceps brachii are antagonistic muscles. When one contracts, the other relaxes.
2. The triceps brachii is located on the posterior side of the upper arm and is primarily responsible for elbow extension.

Verify and Summarize

Among the given options, the triceps brachii is the only muscle that serves as an antagonist to the biceps brachii.

Final Answer

The muscle that works in a pair with the biceps brachii is the triceps brachii.