Nerves of the Palate

• The sensory nerves of the palate, which are branches of the pterygopalatine ganglion, are the greater and lesser palatine nerves.
• They accompany the arteries through the greater and lesser palatine foramina, respectively.

• The greater palatine nerve supplies the gingivae, mucous membrane, and glands of the hard palate.

• The lesser palatine nerve supplies the soft palate.

• Another branch of the pterygopalatine ganglion, the nasopalatine nerve, emerges from the incisive foramen and supplies the mucous membrane of the anterior part of the hard palate.

Vessels of the Palate

• The palate has a rich blood supply from branches of the maxillary artery.

The Nasopharynx

• The nasal part of the pharynx has a respiratory function.
• It lies superior to the soft palate and is a posterior extension of the nasal cavity.
• The nose opens into the nasopharynx via to large posterior apertures called choanae.

• The roof and posterior wall of the nasopharynx form a continuous surface that lies inferior to the body of the sphenoid bone and the basilar part of the occipital bone.
• In the mucous membrane of the roof of the posterior wall of the nasopharynx is a collection of lymphoid tissue, known as the pharyngeal tonsil (commonly known as the adenoids).

• The pharyngeal orifice of the auditory tube is on the lateral wall of the nasopharynx, 1 to 1.5 cm posterior to the inferior concha, and level with the superior border of the palate.
• The orifice is directed inferiorly and has a hood-like tubal elevation over it called the torus of the auditory tube or the torus tubarius (L. torus, swelling).

• Extending inferiorly from the torus is a vertical fold of mucous membrane, known as the salpingopharyngeal fold.

• The collection of lymphoid tissue in the submucosa of the pharynx, posterior to the orifice of the auditory tube, is known as the tubal tonsil.

• Posterior to the torus and the salpingopharyngeal fold, there is a slit-like lateral projection of the pharynx called the pharyngeal recess.
• It extends laterally and posteriorly.

The Soft Palate

• This is the posterior curtain-like part, and has no bony support. It does, however, contain a membranous aponeurosis.
• The soft palate, or velum palatinum (L. velum, veil), is a movable, fibromuscular fold that is attached to the posterior edge of the hard palate.
• It extends posteroinferiorly to a curved free margin from which hangs a conical process, the uvula (L. uva, grape).

• The soft palate separates the nasopharynx superiorly and the oropharynx inferiorly.

• During swallowing the soft palate moves posteriorly against the wall of the pharynx, preventing the regurgitation of food into the nasal cavity.

• Laterally, the soft palate is continuous with the wall of the pharynx and is joined to the tongue and pharynx by the palatoglossal and palatopharyngeal folds.

• The soft palate is strengthened by the palatine aponeurosis, formed by the expanded tendon of the tensor veli palatini muscle.
• This aponeurosis attaches to the posterior margin of the hard palate.

->The two parietal bones (L. paries, wall) form large parts of the walls of the calvaria.
->On the outside of these smooth convex bones, there are slight elevations near the centre called parietal eminences.
->The middle of the lateral surfaces of the parietal bones is crossed by two curved lines, the superior and inferior temporal lines.
->The superior temporal line indicates an attachment of the temporal fascia; the inferior temporal line marks the superior limit of the temporalis muscle.
->The parietal bones articulate with each other in the median plane at the sagittal suture. The medial plane of the body passes through the sagittal suture.
->The inverted V-shaped suture between the parietal bones and the occipital bones is called the lambdoid suture because of its resemblance to the letter lambda in the Greek alphabet.
->The point where the parietal and occipital bones join is a useful reference point called the lambda. It can be felt as a depression in some people.
->In addition to articulation with each other and the frontal and occipital bones, the parietal bones articulate with the temporal bones and the greater wings of the sphenoid bone.
->In foetal and infant skulls, the bones of the calvaria are separated by dense connective tissue membranes at sutures.
->The large fibrous area where several sutures meet are called fonticuli or fontanelles.
->The softness of these bones and looseness of their connections at these sutures enable the calvaria to undergo changes of shape during birth called molding. Within a day or so after birth, the shape of the infant’s calvaria returns to normal.
->The loose construction of the new-born calvaria also allows the skull to enlarge and undergo remodelling during infancy and childhood.

->Relationships between the various bones are constantly changing during the active growth period.
->The increase in the size of the cranium is greatest during the first 2 years, the period of most rapid postnatal growth of the brain.
->The cranium normally increases in capacity until about 15 or 16 years of age; thereafter the cranium usually increases only slightly in size as its bones thicken for 3 to 4 years.

Muscles of the Soft Palate

The Levator Veli Palatini (Levator Palati)

• Superior attachment: cartilage of the auditory tube and petrous part of temporal bone.
• Inferior attachment: palatine aponeurosis.
• Innervation: pharyngeal branch of vagus via pharyngeal plexus.
• This cylindrical muscle runs inferoanteriorly, spreading out in the soft palate, where it attaches to the superior surface of the palatine aponeurosis.
• It elevates the soft palate, drawing it superiorly and posteriorly.
• It also opens the auditory tube to equalise air pressure in the middle ear and pharynx.

The Tensor Veli Palatini (Tensor Palati)

• Superior attachment: scaphoid fossa of medial pterygoid plate, spine of sphenoid bone, and cartilage of auditory tube.
• Inferior attachment: palatine aponeurosis.
• Innervation: medial pterygoid nerve (a branch of the mandibular nerve).
• This thin, triangular muscle passes inferiorly, and hooks around the hamulus of the medial pterygoid plate.
• It then inserts into the palatine aponeurosis.
• This muscle tenses the soft palate by using the hamulus as a pulley.
• It also pulls the membranous portion of the auditory tube open to equalise air pressure of the middle ear and pharynx.

The Palatoglossus Muscle

• Superior attachment: palatine aponeurosis.
• Inferior attachment: side of tongue.
• Innervation: cranial part of accessory nerve (CN XI) through the pharyngeal branch of vagus (CN X) via the pharyngeal plexus.
• This muscle, covered by mucous membrane, forms the palatoglossal arch.
• The palatoglossus elevates the posterior part of the tongue and draws the soft palate inferiorly onto the tongue.

The Palatopharyngeus Muscle

• Superior attachment: hard palate and palatine aponeurosis.
• Inferior attachment: lateral wall of pharynx.
• Innervation: cranial part of accessory nerve (CN XI) through the pharyngeal branch of vagus (CN X) via the pharyngeal plexus.
• This thin, flat muscle is covered with mucous membrane to form the palatopharyngeal arch.
• It passes posteroinferiorly in this arch.
• This muscle tenses the soft palate and pulls the walls of the pharynx superiorly, anteriorly and medially during swallowing.

The Musculus Uvulae

• Superior attachment: posterior nasal spine and palatine aponeurosis.
• Inferior attachment: mucosa of uvula.
• Innervation: cranial part of accessory through the pharyngeal branch of vagus, via the pharyngeal plexus.
• It passes posteriorly on each side of the median plane and inserts into the mucosa of the uvula.
• When the muscle contracts, it shortens the uvula and pulls it superiorly.