ANATOMY

Detailed explanation-1: -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-2: -The corrugator supercilii muscle is a small, narrow, pyramidal muscle close to the eye. It arises from the medial end of the superciliary arch, and inserts into the deep surface of the skin of the eyebrow. It draws the eyebrow downward and medially, producing the vertical wrinkles of the forehead.

Detailed explanation-3: -The corrugator supercilii muscles are two small, triangular facial muscles, which contribute to movement of the eyebrows, including frowning. They are located deep to the frontal part of occipitofrontalis and orbicularis oculi muscles, with which they blend 2.

Detailed explanation-4: -The frontalis muscle (from Latin ‘frontal muscle’) is a muscle which covers parts of the forehead of the skull. Some sources consider the frontalis muscle to be a distinct muscle. However, Terminologia Anatomica currently classifies it as part of the occipitofrontalis muscle along with the occipitalis muscle.