The Occipitalis muscle has which primary action?

The Occipitalis muscle has which primary action?

• A. Origin: galea aponeurotica
• B. Insertion: galea aponeurotica
• C. Action: pulls scalp posteriorly
• D. Blood supply: none

Answer: (C)

The main action of the occipitalis muscle is to pull the scalp posteriorly. It runs from the occipital bone up to the galea aponeurotica, the fibrous sheet that covers the top of the skull and connects to the frontal belly. When the occipitalis contracts, it tenses the galea and moves the scalp toward the back of the head. This action can be part of a coordinated movement with the frontalis muscle, which can raise the eyebrows, but the occipitalis itself primarily retracts the scalp. The other options describe where the muscle attaches rather than what it does, and one option is simply inaccurate about blood supply.

The main action of the occipitalis muscle is to pull the scalp posteriorly. It runs from the occipital bone up to the galea aponeurotica, the fibrous sheet that covers the top of the skull and connects to the frontal belly. When the occipitalis contracts, it tenses the galea and moves the scalp toward the back of the head. This action can be part of a coordinated movement with the frontalis muscle, which can raise the eyebrows, but the occipitalis itself primarily retracts the scalp. The other options describe where the muscle attaches rather than what it does, and one option is simply inaccurate about blood supply.