ANATOMY

Detailed explanation-1: -Occipitofrontalis muscle has several actions depending on which of its attachments is fixed; When its aponeurotic attachment is fixed, the frontal belly elevates the eyebrows and skin of the forehead, producing a facial expression of shock or surprise.

Detailed explanation-2: -The frontal belly of the occipitofrontalis originates from the epicranial aponeurosis (galea aponeurotica).

Detailed explanation-3: -The frontalis muscle is responsible for elevating the eyebrows, while the corrugator supercilii, orbicularis oculi, and procerus play a role in its depression.

Detailed explanation-4: -Purpose: Occipital belly (OB) of occipitofrontalis muscle (epicranius) is a muscle which covers the occipital part of the skull. The posterior auricular nerve (PAN) is the first extracranial branch of the facial nerve, which supplies the OB.