What is the function of the buccinator muscle?

What is the function of the buccinator muscle?

• A. Elevates the jaw
• B. Closes the eyelids
• C. Contracts the cheeks to narrow the mouth
• D. Depresses the lips

Answer: (C)

This item tests the function of the buccinator, the muscle that forms the cheek and controls how the cheek is pressed toward the teeth. When it contracts, the buccinator tenses the cheek and presses it against the teeth, which narrows the mouth opening and helps keep food between the teeth during chewing while also aiding in blowing or whistling. That’s why contracting the cheeks to narrow the mouth best fits the buccinator’s role. It's not involved in elevating the jaw, closing the eyelids, or depressing the lips—those actions come from other muscles.

This item tests the function of the buccinator, the muscle that forms the cheek and controls how the cheek is pressed toward the teeth. When it contracts, the buccinator tenses the cheek and presses it against the teeth, which narrows the mouth opening and helps keep food between the teeth during chewing while also aiding in blowing or whistling. That’s why contracting the cheeks to narrow the mouth best fits the buccinator’s role. It's not involved in elevating the jaw, closing the eyelids, or depressing the lips—those actions come from other muscles.