Contraction of the levetor labii superioris, zygomatic minor, and levator labii superioris alaeque nasi elevate the upper lip; contraction of the depressor labii inferioris depress the lower lip.

• 提上唇肌、颧肌、提鼻翼肌的收缩动作会牵动上唇，使之往上移动，而降下唇肌则掌管下唇的收缩及下拉。