PALATE

The muscles of the soft palate are the tensor veli palatini, the levator veli palatini, the palatoglossus, the palatopharyngeus, and the musculus uvulae.

• The greater and lesser palatine nerves from the maxillary division of the trigeminal nerve enter the palate through the greater and lesser palatine foramina.
• The nasopalatine nerve a branch of the maxillary nerve, enters the front of the hard palate through the incisive foramen.
• The glossopharyngeal nerve also supplies the soft palate.
• Facial nerve supplies submandibular and sublingual salivary parasympathetic glands, lacrimal gland, and glands of nose and palate.

“Greater or anterior palatine branches of pterygopalatine ganglion supplies hard palate and lateral wall of the nose while the lesser or middle and posterior palatine nerve supply the soft palate and tonsils”.

• All the muscles of the soft palate except tensor veli palatini are supplied by pharyngeal plexus (fibers of the plexus are derived from the cranial part of the accessory nerve through the vagus nerve)
• Tensor veli palatini is supplied by mandibular nerve.

Ans.A. Palatoglossus

The muscles of the tongue, with the exception of palatoglossus, are supplied by the hypoglossal nerve.

Palatoglossus is supplied via the pharyngeal plexus.

With the exception of tensor veli palatini, which is supplied by the motor branch of the mandibular division of the trigeminal through the nerve to medial pterygoid, the muscles are supplied by the cranial part of the accessory nerve via the pharyngeal plexus.

The cranial root of the accessory nerve is smaller than the spinal root. It exits the skull through the jugular foramen and unites for a short distance with the spinal root. Its fibers innervate the pharyngeal and palatal muscles, except tensor veli palatini. 

Because the cranial part of accessory nerve (CN XI) leaves the jugular foramen as joining the CN X, it is sometimes considered part of the plexus as well

The tensor veli palatini is supplied by the medial pterygoid nerve, a branch of mandibular nerve, the third branch of the trigeminal nerve – the only muscle of the palate not innervated by the pharyngeal plexus

D. i.e. Incisive foramen

The incisive foramen is dividing landmark between the primary & secondary palateQ; and anterior & posterior cleft deformities

B i.e. Facial nerve

Ans. D: Both A and B

Pharyngotympanic (Auditory) tube is 4 cm long, consists of two parts:

• Bony part forms posterior and lateral one third of the tube (12 cm long)
• Cartilaginous part forms the anterior and medial two third (25 cm long)
• Connects the middle ear with the nasopharynx
• Equalizes pressure on both sides of the tympanic membrane
• Usually closed to prevent entrance of particles from the nose
• Muscles that open auditory tube while swallowing, yawning and sneezing are levator veli palatini and tensor veli palatini

DEVELOPMENT OF THE TONGUE :‑

I. Epithelium

a)       Ant 2/3 — lingual swellings of 1st arch and tuberculum impar

b)     Post 1/3 — large dorsal part of hypobranchial eminence, Le. 3rd arch

c)       Posterior most part — small dorsal part of the hypobranchial eminence, i.e. 4th arch

II. Muscles

From occipital myotomes except palatoglossus which is derived from the 6th arch.

 Passavant ridge

• Near the superior margin of pharynx, a few fibres of superior constrictor blend with a band of muscle fibres belonging to the palatopharyngeus muscle.
• These fused fibres form a band or ring around the posterior wall and sidewalls of the nasopharyngeal isthumus.
• When the soft palate is elevated this muscle band appears as a ridge is known as passavant’s ridge.