Understanding Facial Muscles and Expressions

Sep 10, 2024

Facial Muscles and Expressions

Overview

  • Muscles Function: Muscles primarily contract and shorten, generally moving bones, but in the face, they often move skin.
  • Facial Muscles: Used for speech, ingestion, emotional expression, and symbolic gestures.

Evolution and Research

  • Darwin: Facial expressions as residual actions of complete behavioral responses.
  • Sylvan Tompkins: Emotion as the basis of human motivation, rooted in facial expressions.
  • Ekman: Universality of facial expressions, proven with studies in New Guinea.

Emotional Feedback

  • Botox Experiment: Paralyzing frown muscles can affect anger emotions, showing that expressions influence internal feelings.

Universal Facial Expressions

  1. Disgust: Wrinkling of the nose, exposure of canine teeth—like a dog snarling.
  2. Anger: Furrowed brow, raised nostrils, widened eyes, sometimes exposed teeth.
  3. Happiness: Two types of smiles:
    • Polite (corners of the mouth raised).
    • True (eye sockets contracted).
  4. Surprise vs. Fear:
    • Both involve raised eyebrows and eyelids.
    • Surprise: Jaw drops.
    • Fear: Mouth stretches horizontally.
  5. Sadness: Inner eyebrow raised, corners of mouth pulled down.
  6. Contempt: Asymmetric smirk, showing superiority, often a negative indicator.

Muscle Anatomy and Function

  • Origin and Insertion: Terms for where a muscle starts and ends, often bone-related but sometimes involving skin.
  • Action: Muscle contraction results in movement.
  • Innervation: Most facial muscles are innervated by the facial nerve (cranial nerve VII).

Facial Muscles Specifics

  • Frontalis Muscle: Raises eyebrows, wrinkles forehead; located at the front of the head attached to skin of eyebrows and nose.
  • Corrugator Supercilii Muscle: Lowers brows, causing vertical forehead wrinkles; involved in frowning and sun glare prevention.
  • Orbicularis Oculi Muscle: Surrounds the eye; responsible for closing eyelids and creating crow's feet.

Practical Applications

  • Trigger Points: Areas in muscles like the frontalis where pressure can relieve tension-related pain.
  • Botox Use: Can be used for aesthetic and therapeutic reasons (e.g., migraines), affecting muscle activity.

Key Takeaways

  • Facial muscles play a critical role in communication and emotional expression.
  • Understanding muscle anatomy aids in medical and cosmetic fields.
  • Emotional expressions have both external and internal impacts on individuals.