Physiology of Tongue Movements and Articulation

Physiology of Tongue Movements

  • Superior Longitudinal Muscles

    • Function: Elevate the tongue tip.

  • Inferior Longitudinal Muscles

    • Function: Depress the tongue tip.

  • Left and Right Superior & Inferior Longitudinal Muscles

    • Function: Deviate the tongue tip to the left and right.

  • Transverse Intrinsic Muscles

    • Function: Narrow the tongue.

  • Genioglossus

    • Function: Depression of tongue body.

    • Additional Function: Elevates the sides of the tongue, creating a broad groovening effect.

    • Result: Formation of a deep central groove and broad groovening.

Tongue Movement Functions

  • Protrusion of Tongue

    • Primary Muscle: Anterior genioglossus.

    • Supporting Muscles: Superior longitudinal and inferior longitudinal muscles for balancing and pointing the tongue.

  • Retracting Tongue

    • Primary Muscle: Anterior genioglossus.

    • Supporting Muscles: Superior longitudinal and inferior longitudinal muscles to shorten the tongue; styloglossus to retract the tongue into the pharyngeal cavity.

  • Elevation of Posterior Tongue

    • Primary Muscle: Palatoglossus for the elevation of the sides of the tongue.

    • Supporting Muscles: Transverse intrinsic muscles to bunch the tongue.

  • Depression of Tongue Body

    • Primary Muscle: Genioglossus to depress the middle part of the tongue.

    • Supporting Muscle: Hypoglossus to depress the sides of the tongue.

Instruments of Measurements

  • Cineradiography

    • Definition: A technique that produces images of moving objects, specifically articulators in motion.

  • Electrography

    • Definition: A method that plots the movement of articulators in space by placing sensors on structures.

  • Surface Electromyography

    • Definition: A technique that measures muscle activity related to the movements of articulators.

  • Sound Spectrogram

    • Definition: A tool that measures speech and plots data of various speech spectra.

Function of Articulators

  • Lips

    • Lower Lip: Performs closure efficiently with greater velocity and force, doing most of the work in closure.

  • Mandible

    • Function: Assists the lips and changes position for tongue movements; tightly closes when necessary.

    • Importance: Essential for speech intelligibility and carries articulators to their targets.

  • Tongue

    • Function: Most important articulator, responsible for the majority of phoneme production.

    • Extrinsic Muscles: Set the basic position of the tongue.

    • Intrinsic Muscles: Provide the microstructure necessary for articulation.

  • Velum

    • Function: Involved in nasal assimilation; the soft palate opens and closes rapidly.

    • Relevance: Rapid movement is vital during speech and non-speech functions.

Definitions

  • Articulation

    • Definition: The joining of two elements; crucial for shaping speech sounds.

  • Articulatory System

    • Definition: A collection of mobile and immobile articulators interacting to form speech.