GEN ANA2 : BONE

• Muscles of the face are embedded in the superficial fascia and arise from the bones of the skull, inserted into the skin
• Muscles of the eyelids:

  • Move skin of face, close eyes, open/close mouth
  • Convey emotions by gestures (e.g. sneering, contempt)
  • Most originate from bones and insert into the skin
  • Many named for action in Latin/Greek
  • Movements elicited in test for Facial Nerve function
• Orbicularis Oculi:

  • Close eye
  • Palpebral part: Close eyelids
  • Orbital part: Buries eyelids, e.g. sandstorm
• Muscles of the nostrils:

  • Compressor nares: Lateral to bridge of nose, compresses nasal cartilage
  • Dilator nares: Lateral to nostrils, dilates
  • Procerus: Wrinkles skin of nose
• Muscles of the lips and cheeks:

  • Orbicularis Oris: Surrounds/closes mouth
• Muscles of upper lip:

  • Levator Labii Superioris: Lifts upper lip
  • Zygomaticus Major & minor: Raise & pull upper lip laterally
• Muscles at angle of mouth:

  • Levator Anguli Oris: Raise corner of mouth
  • Risorius: Smiling
  • Depressor Anguli Oris: Tragedy
• Muscles of lower lip and chin:

  • Depressor Labii Inferioris: Depresses lower lip
  • Mentalis: Wrinkles skin of chin
• Buccinator:

  • Latin for trumpet player
  • Compresses mouth & keeps food between teeth when chewing
• Motor innervation to muscles of facial expression is through the Facial Nerve (Cranial Nerve VII)

  • Leaves skull via stylomastoid foramen
  • Divides in parotid gland into 5 terminal branches:

  1. Temporal

  2. Zygomatic

  3. Buccal

  4. Mandibular

  5. Cervical

  • Note: Buccal Br. VII = Motor; Buccal Br. V = Sensory