Muscles of Facial Expression

Module 10.6: Muscles of Facial Expression

Importance of Facial Muscles

  • Functions:
    • Essential in eating.
    • Valuable for communication.

Origins and Insertions

  • Most muscles of facial expression originate on the surface of the skull, with an exception:
    • Platysma muscle of the neck.
  • At the insertion points:
    • Muscle fibers of the epimysium weave into the fibers of the superficial fascia (subcutaneous layer) and the dermis of the skin.
    • Contraction of these muscles causes movement of the skin, facilitating facial expressions.

Major Muscles of Facial Expression

Overview of Major Muscles:
  • Frontal Belly of Occipitofrontalis
  • Orbicularis Oculi
  • Epicranial Aponeurosis
    • The occipitofrontalis muscle forms the scalp, consisting of two parts (bellies) connected through a collagenous sheet known as the epicranial aponeurosis.
Illustrated Views of Facial Muscles
  • Lateral View: Highlights major facial muscles, showcasing the abundance involved in lip movements.
  • Anterior View: Displays superficial muscles on the right side of the face and deeper muscles visible on the left side, including:
    • Temporalis
    • Corrugator Supercilii
    • Procerus
    • Nasalis
    • Zygomaticus Minor
    • Zygomaticus Major
    • Orbicularis Oris
    • Risorius
    • Levator Labii Superioris
    • Levator Anguli Oris
    • Masseter
    • Buccinator
    • Platysma
    • Mentalis (cut)
    • Frontal Belly
    • Epicranial Aponeurosis
    • Orbicularis Oculi
    • Nasalis

Muscles of the Mouth and Cheek

  • Key Muscles Associated with the Mouth:
    • Levator Labii Superioris
    • Zygomaticus Minor
    • Zygomaticus Major
    • Buccinator
    • Orbicularis Oris
    • Risorius
    • Mentalis (cut)
    • Depressor Labii Inferioris
    • Temporalis
    • Masseter
    • Depressor Anguli Oris
Key Identifications:
  • Identify the muscle involved in whistling: Buccinator.
  • Review Activity: List each muscle associated with the mouth.

Summary

  • Understanding the anatomy and function of facial muscles enhances knowledge in the muscular system, particularly their roles in expression and functional movements critical for human interaction and behavior.
  • Each muscle serves specific purposes in facial mobility, driven by their origins and insertions on the skull and skin.