Topics

Topic

design image
Posterior part of tongue

The posterior part of the tongue, also known as the base of the tongue, constitutes the posterior one-third of the tongue and lies within the oropharynx. It is separated from the anterior two-thirds by the sulcus terminalis, a V-shaped groove whose apex points posteriorly toward the foramen cecum.

Unlike the anterior tongue, which is primarily involved in articulation and manipulation of food, the posterior tongue has a dominant role in swallowing, airway protection, and immune function. Its surface is irregular and nodular due to the presence of lingual tonsils, which are aggregates of lymphoid tissue forming part of Waldeyer’s ring.

The posterior tongue is composed predominantly of muscle, covered by mucosa, and anchored inferiorly to the hyoid bone and epiglottis, forming a dynamic structure essential for coordinated deglutition.

Synonyms

  • Base of the tongue

  • Posterior third of the tongue

  • Oropharyngeal tongue

Location and Structure

  • Extent: From the sulcus terminalis to the epiglottis

  • Surface: Nodular and irregular due to lingual tonsils

  • Mucosa: Thick, non-keratinized stratified squamous epithelium

  • Muscular core:

    • Intrinsic muscles: Alter tongue shape

    • Extrinsic muscles: Primarily genioglossus, hyoglossus, and styloglossus

  • Midline: Marked by a fibrous lingual septum

Relations

  • Anteriorly: Sulcus terminalis and anterior two-thirds of the tongue

  • Posteriorly: Epiglottis and valleculae

  • Superiorly: Oropharyngeal cavity

  • Inferiorly: Hyoid bone and tongue root

  • Laterally: Palatoglossal arches and tonsillar pillars

Function

  • Swallowing: Propels the bolus posteriorly into the oropharynx

  • Airway protection: Coordinates with epiglottis during deglutition

  • Immune defense: Lingual tonsils participate in mucosal immunity

  • Speech modulation: Contributes to resonance and posterior articulation

MRI Appearance

T1-weighted images:

  • Muscle of the tongue: Intermediate signal intensity

  • Fat planes between muscles: Bright signal

  • Lingual tonsils: Intermediate signal, slightly heterogeneous

  • Mucosal surface: Thin low-to-intermediate signal lining

T2-weighted images:

  • Tongue muscles: Intermediate-to-slightly low signal, darker than fat

  • Lingual tonsils: Mildly hyperintense relative to muscle due to lymphoid tissue

  • Saliva and oropharyngeal lumen: Bright signal

  • Clear delineation of intrinsic and extrinsic muscle planes

STIR:

  • Tongue musculature: Intermediate-to-dark signal

  • Fat planes: Suppressed

  • Lingual tonsillar tissue: Intermediate signal, slightly higher than muscle

  • Provides uniform visualization of muscular architecture

T1 Fat-Saturated Post-Contrast:

  • Tongue muscles: Homogeneous mild enhancement

  • Lingual tonsils: Moderate symmetric enhancement reflecting lymphoid vascularity

  • Mucosal surface: Thin enhancing lining

  • Symmetric enhancement is a normal feature of the posterior tongue

CT Appearance

Non-Contrast CT:

  • Tongue musculature: Homogeneous soft-tissue density

  • Lingual tonsils: Slightly lobulated soft-tissue prominence at tongue base

  • Fat planes: Low attenuation separating muscle groups

  • Valleculae and airway: Air-filled, well delineated

Post-Contrast CT:

  • Tongue muscles: Uniform enhancement

  • Lingual tonsils: Symmetric moderate enhancement

  • Clear depiction of tongue base contour and oropharyngeal airway

  • Useful for anatomical mapping and symmetry assessment

X-ray Appearance

Lateral neck radiograph:

  • Posterior tongue seen as a soft-tissue density anterior to the oropharyngeal air column

  • Vallecula visible as an air-filled space between tongue base and epiglottis

  • Tongue base contour appears smooth and symmetric

  • Limited soft-tissue contrast; primarily useful for assessing airway patency

MRI image

Posterior part of tongue MRI anatomy labelled image-img-00000-00000

CT image

Posterior part of tongue CT anatomy labelled image-img-00000-00000

X Ray image

Posterior part of tongue X RAY anatomy labelled image-img-00000-00000