The Palate - Hard Palate - Soft Palate - Uvula (2024)

The palate (alsoknown as the ‘roof of the mouth’), forms a division between the nasal andoral cavities. It is separated into two distinct parts:

• Hard palate– comprised of bone.
  • It is immobile.
• Soft palate – comprised of muscle fibres covered by a mucous membrane.
  • It can be elevated to close the pharyngeal isthmus during swallowing – this prevents the food bolus from entering the nasopharynx.

In this article, we will look at the anatomy of the palate; its structure, function and neurovascular supply.

Structure

The palate divides the nasal cavity and the oral cavity, with the hard palate positionedanteriorly and the soft palateposteriorly.

It forms both the roof of the mouth and the floor of the nasal cavity. Reflecting this, the superior and inferior palatal surfaces have different mucosal linings:

• Superior aspect of palate (nasal cavity) – respiratory epithelium.
• Inferiorly aspect of palate (oral cavity) – oral mucosa, populated by secretorysalivary glands.

Hard Palate

The hard palate forms theanterior aspectof the palate.

The underlying bony structure is composed of (i) palatine processes of the maxilla; and (ii) horizontal plates of the palatine bones.

There are three main foramina/canals in the hard palate:

• Incisive canal – located in the anterior midline, transmits the nasopalatine nerve and descending palatine artery.
• Greater palatine foramen – located medial to the third molar tooth, transmits the greater palatine nerve and vessels
• Lesser palatine foramina – located in the pyramidal process of the palatine bone, transmits the lesser palatine nerve.

Soft Palate

The soft palateis located posteriorly. It is mobile, and comprised of muscle fibres covered by a mucous membrane.

Anteriorly, it is continuous with the hard palate and with the palatine aponeurosis. The posterior border of the soft palate is free (i.e. not connected to any structure), and has a central process that hangs from the midline – the uvula.

The soft palate also forms the roof of the fauces;an area connecting the oral cavity and the pharynx. Two arches bind the palate to the tongue and pharynx; thepalatoglossal archesanteriorly and thepalatopharyngeal archesposteriorly. Between these two arches lie the palatine tonsils, which reside in the tonsillar fossae of the oropharynx.

Muscles of the Soft Palate

There are five muscles which give the actions of the soft palate.

They are all innervated by thepharyngeal branchof thevagus nerve (CN X)– apart from Tensor veli palatini – which is innervated by the medial pterygoid nerve (a branch of CN V₃).

Tensor Veli Palatini

• Attachments:Originates from the medial pterygoid plate of the sphenoid and inserts into the palatine aponeurosis.
• Function: Tenses the soft palate.

Levator Veli Palatini

• Attachments: Arises from the petrous temporal bone and the eustachian tube, before inserting into the palatine aponeurosis.
• Function: Elevation of the soft palate.

Palatoglossus

• Attachments: Originates from the palatine aponeurosis, and travels anteriorly, laterally and inferiorly to insert into the side of thetongue.
• Function: Pulls the soft palate towards the tongue.

Palatopharyngeus

• Attachments: Arises from the palatine aponeurosis and the hard palate, and inserts into the upper border of the thyroid cartilage.
• Function: Tenses soft palate and draws the pharynx anteriorly on swallowing.

Musculus Uvulae

• Attachments: Arises from the posterior nasal spine and the palatine aponeurosis, and inserts into the mucous membrane of the uvula.
• Function: Shortens the uvula.

Vasculature

The palate receives arterial supply primarily from thegreater palatine arteries, which run anteriorly from the greater palatine foramen.

In addition, the anastomosis between thelesser palatine arteryandascending palatine arteryprovide collateral supply to the palate.

Venous drainage is into thepterygoid venous plexus.

Innervation

Sensory innervation of the palate is derived from themaxillary branch of thetrigeminal nerve (CN V).The greater palatine nerve innervates most of the glandular structures of the hard palate.

The nasopalatine nerve innervates the mucous membrane of the anterior hard palate and the lesser palatine nerves innervate the soft palate.