ABOVE: The muscles of the upper face include the following:

• Frontalis - pulls the eyebrows up and is the basis of AUs 1 and 2 in FACS
• Procerus or Pyramidalis - pulls the glabella down and is part of the basis of AU 4 in FACS
• Orbicularis oculi - squints the eyes, and consists of two major parts (see below): an outer part, the basis for AU 6 in FACS; the inner part, mostly on the eyelids is the basis for AU 7 in FACS
• Zygomatic - retracts and pulls the lip corners upwards
• Nasalis (transverse or compressor part) - compresses the nostrils
• Quadratus labii superioris - a muscle in the medial cheek and nose are that has multiple strands, including:
• Levator labii superioris alaque nasi or Caput angulare - wrinkles the nose and is the basis for AU 9 in FACS
• Levator labii superioris or Caput infraobitalis - pulls the upper lip upwards and is the basis of AU 10 in FACS
• Caput zygomatic - more lateral strand often not separately distinguished

Other labeled features:

• Galea aponeurotica - tough tissue on the top of the skull
• Sulcus nasolabialis - nasolabial furrow that runs from the nasal wing to the corner of the mouth

Muscles of the right eyelid

Muscles of the right eyelid looking from inside the eye