[3] The frontalis muscle is supplied by the facial nerve[4] and receives blood from the supraorbital and supratrochlear arteries.

The frontalis muscle is thin, of a quadrilateral form, and intimately adherent to the superficial fascia.

From these attachments the fibers are directed upward, and join the galea aponeurotica below the coronal suture.

The medial margins of the frontalis muscles are joined together for some distance above the root of the nose; but between the occipitales there is a considerable, though variable, interval, occupied by the galea aponeurotica.

This article incorporates text in the public domain from page 379 of the 20th edition of Gray's Anatomy (1918)