Hard Palate (palatum durum)
The anterior portion of the roof of the oral cavity is represented by the hard palate (palatum durum). Its bony framework (palatum osseum) is formed by the palatine processes of the maxillae anteriorly and the horizontal plates of the palatine bones posteriorly.
The mucosa of this region has an important feature: it is firmly fused to the periosteum. Numerous palatine glands (glandulae palatinae) are located within the submucosa. Viewed from below, the palatine raphe (raphe palati) runs along the exact midline, terminating anteriorly in a small elevation—the incisive papilla (papilla incisiva).
Soft Palate (palatum molle)
The posterior region is the soft palate (palatum molle), also known as the palatine velum (velum palatinum). It is a mobile muscular-fibrous structure. Its structural foundation is the dense palatine aponeurosis (aponeurosis palatina), to which the muscles attach. Externally, this structure is covered by mucous membrane.
The free margin of the velum hangs downward and terminates centrally in the palatine uvula (uvula palatina). Laterally, two mucosal folds diverge from the soft palate:
- Anteriorly—the palatoglossal arch (arcus palatoglossus);
- Posteriorly—the palatopharyngeal arch (arcus palatopharyngeus).
The soft palate plays a critical role in swallowing, isolates the nasopharynx from the oral cavity, and is essential for proper speech articulation. Blood supply is provided by the descending and ascending palatine arteries, while innervation is supplied by the greater and lesser palatine nerves, as well as nasopalatine branches.
Palatine Tonsil (tonsilla palatina)
Located in the tonsillar fossa between the palatoglossal and palatopharyngeal arches is the palatine tonsil (tonsilla palatina). This is a paired, bean-shaped organ that performs an immune function.
From the pharyngeal side, the tonsil is surrounded by a fibrous layer—the tonsillar capsule (capsula tonsillaris)—and is closely related to the superior pharyngeal constrictor muscle (m. constrictor pharyngis superior). The internal surface of the organ is uneven and pitted with tonsillar fossulae (fossulae tonsillares), which lead deeper into the tonsillar crypts (criptae tonsillares). Lymphoid follicles are clustered around these crypts.
The tonsils receive blood from the ascending and descending palatine arteries, as well as the tonsillar branch of the facial artery. Innervation is provided by branches of the glossopharyngeal and vagus nerves via the pharyngeal plexus.
Muscles of the Palate and Fauces
Movements of the soft palate, assistance in swallowing, phonation, and ventilation of the pharyngotympanic (auditory) tube are managed by a specialized muscular apparatus comprising five muscles:
- Tensor veli palatini muscle (m. tensor veli palatini). Originates from the scaphoid fossa of the sphenoid bone and the cartilage of the auditory tube, hooks around the pterygoid hamulus, and inserts into the palatine aponeurosis. It tensions the palate and opens the pharyngeal orifice of the auditory tube.
- Levator veli palatini muscle (m. levator veli palatini). Originates from the inferior surface of the petrous part of the temporal bone. It elevates the soft palate, narrowing the pharyngeal opening of the auditory tube.
- Musculus uvulae (mm. uvulae). Originates from the posterior nasal spine and the palatine aponeurosis. It shortens and elevates the uvula.
- Palatoglossus muscle (m. palatoglossus). Located within the anterior arch, originating from the tongue base. It narrows the fauces by pulling the arches toward the tongue.
- Palatopharyngeus muscle (m. palatopharyngeus). Located within the posterior arch, extending from the pharyngeal wall and thyroid cartilage. It approximates the arches and elevates the larynx and pharynx during swallowing. Some of its fibers form the salpingopharyngeus muscle.
All these muscles receive their blood supply from the palatine arteries.