Location and Topography
The palatine uvula is the central structure of the soft palate (palatum molle or velum palatinum), which has an irregular quadrilateral shape. The uvula projects inferiorly from the middle of the palatine velum.
Boundaries of the Fauces:
- Superior: Soft palate.
- Lateral: Palatoglossal arches.
- Inferior: Dorsum of the tongue (dorsum linguae).
The conical shape of the uvula is due to the gradual tapering of its muscular bundles posteriorly.
Structure: Muscles of the Uvula
The structural core of the uvula is the paired musculus uvulae (m. uvulae), consisting of two muscle bundles converging at the midline.
- Origin: The bundles originate from the posterior nasal spine of the hard bone (spina nasalis posterior) and the palatine aponeurosis.
- Course of fibers: They course medially to insert into the mucous membrane of the uvula. Most bundles attach to the palatine aponeurosis, thickening the midline to form the palatine raphe.
- Function: Shortens and elevates the uvula.
In addition to the m. uvulae in the center, adjacent muscles contribute to the soft palate apparatus: m. palatoglossus (in the palatoglossal arches), m. palatopharyngeus (in the palatopharyngeal arches), as well as the tensor veli palatini and levator veli palatini muscles (m. tensor veli palatini and m. levator veli palatini).
Clinical Significance and Examination
Examination of the palatine uvula is performed during oral cavity assessment: after inspecting the vestibule and oral cavity proper, the clinician evaluates the fauces and pharynx.
Functional Test: The patient is asked to open their mouth and say "Ah". Normally, the soft palate elevates symmetrically, tensing equally on both sides, and the uvula remains strictly in the midline. Swallowing is unimpaired, and there is no nasal tone to the voice.
Pathological Findings:
- Vagus Nerve Lesion: The soft palate sags on the affected side. Due to pharyngeal constrictor muscle paresis, the uvula deviates toward the healthy side. This is accompanied by a diminished gag reflex, dysphagia, and a nasal voice quality (nasal speech/hypernasality) due to impaired separation of the nasal and oral cavities.
- Maxillofacial Trauma: In a Le Fort III fracture of the maxilla, the soft palate may be displaced posteriorly. The uvula can irritate the posterior pharyngeal wall mucosa, causing a foreign body sensation, choking, and periodic gagging.
- Inflammatory Processes: In acute tonsillopharyngitis, the uvula becomes edematous alongside hyperemia of the posterior pharyngeal wall and palatine tonsils.
Do Not Confuse: Cerebellar Uvula
In anatomy, the term "uvula" is also used for central nervous system structures. The uvula of the cerebellar vermis (uvula vermis) is part of the posterior lobe of the cerebellum. Additionally, the lingula of the cerebellum (lingula cerebelli) is located in the anterior lobe. These intracranial structures are unrelated to the oral cavity.