Question

multiple select question

select all that apply

which are actions of the occipital belly of the occipitofrontalis?

wrinkles skin of forehead
retracts scalp
draws scalp forward
elevates eyebrows
fixes galea aponeurotica

Explanation:

Identify muscle anatomy

Using the Occipitofrontalis Muscle knowledge point, we identify that the occipitofrontalis is a bipartite muscle of the scalp consisting of two muscle bellies: the frontal belly (frontalis) and the occipital belly (occipitalis), connected by a broad tendon called the epicranial aponeurosis (galea aponeurotica).

Analyze occipital belly actions

Using the Occipital Belly Action knowledge point:

• The occipital belly originates from the superior nuchal line of the occipital bone and inserts into the galea aponeurotica.
• When it contracts, it pulls the galea aponeurotica posteriorly, which directly retracts scalp.
• By pulling the aponeurosis backward, it also tenses or fixes galea aponeurotica, providing a stable anchor for the frontal belly to act.

Evaluate other options

• "Wrinkles skin of forehead" and "Elevates eyebrows" are actions of the frontal belly (frontalis), not the occipital belly.
• "Draws scalp forward" is also an action associated with the contraction of the frontal belly.

Answer:

• Wrinkles skin of forehead
• Retracts scalp (Correct answer)
• Draws scalp forward
• Elevates eyebrows
• Fixes galea aponeurotica (Correct answer)