The depressor supercilii is a small, narrow muscle located in the eyebrow region of the face, just above the eye. It extends from the eyebrow's medial end to the nose's upper part. The depressor supercilii muscle is responsible for pulling the eyebrow downward and medially, which can create a facial expression of sadness or concern. The muscle also helps to regulate the amount of light entering the eye by narrowing the opening between the eyelids. The depressor supercilii muscle is innervated by the temporal branch of the facial nerve (cranial nerve VII) and works in conjunction with other facial muscles to produce a range of facial expressions. Dysfunction or weakness of the depressor supercilii muscle can lead to difficulties with facial expressions, such as the ability to furrow the eyebrows.