NEET MDS Lessons
Anatomy
The Salivary Glands
- There are three large, paired salivary glands: the parotid, submandibular, and sublingual glands.
- In addition to the main salivary glands, there are numerous small accessory salivary glands scattered over the palate, lips, cheeks, tonsils, and tongue.
- 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.
Muscles of the larynx
Extrinsic muscles
suprahyoid: raise larynx, depress mandible for swallowing
infrahyoid: lower larynx for swallowing
both stabilize hyoid for tongue movements
- U-shaped bone
- Body
- Greater horn
- Lesser horn
- Suspended by ligaments from the styloid process
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 Lateral Pterygoid Muscle
- This is a short, thick muscle that has two heads or origin.
- It is a conical muscle with its apex pointing posteriorly.
- Origin: superior head—infratemporal surface and infratemporal crest of the greater wing of the sphenoid bone, inferior head—lateral surface of lateral pterygoid plate.
- Insertion: neck of mandible, articular disc, and capsule of temporomandibular joint.
- Innervation: mandibular nerve via lateral pterygoid nerve from anterior trunk, which enters it deep surface.
- Acting together, these muscles protrude the mandible and depress the chin.
- Acting alone and alternately, they produce side-to-side movements of the mandible.
The Articular Capsule
- The capsule of this joint is loose.
- The thin fibrous capsule is attached to the margins of the articular area on the temporal bone and around the neck of the mandible.