Parotid Gland, Infratemporal Fossa, and Oral Cavity Anatomy

Flashcards covering the anatomical structures, innervation, and vasculature of the parotid region, infratemporal fossa, TMJ, and oral cavity based on lecture slides.

Temporal region

Includes the temporal and infratemporal fossae, situated superior and inferior to the zygomatic arch respectively.

Infratemporal fossa (roof)

Formed by the greater wing of the sphenoid bone, transmitting the mandibular branch of the trigeminal nerve and the middle meningeal artery.

Mandibular nerve ($V_3$)

A branch of the trigeminal nerve ($CN V$) that enters the infratemporal fossa via the foramen ovale, giving rise to motor and sensory branches.

Chorda tympani

A branch of the facial nerve ($CN VII$) that follows the lingual nerve and provides taste innervation to the anterior $2/3$ of the tongue.

Maxillary artery

The terminal branch of the external carotid artery; it originates in the infratemporal fossa and gives rise to the middle meningeal artery.

Pterygoid venous plexus

Drains the eye and connects to the cavernous sinus, providing a potential route for facial infections to spread intracranially.

Temporomandibular joint ($TMJ$)

Formed by the articulation between the mandibular fossa and articular tubercle of the temporal bone, and the head of the mandible.

Lateral ligament

An extracapsular ligament running from the articular tubercle to the mandibular neck that acts to prevent posterior dislocation of the joint.

Masseter

The most powerful muscle of mastication; it is quadrangular with deep and superficial parts and acts to elevate the mandible.

Temporalis muscle

Originates from the temporal fossa and attaches to the coronoid process of the mandible; acts in elevation and retraction of the mandible.

Myringoplasty

A surgical operation to repair a perforated tympanic membrane, often using harvested temporalis fascia.

Lateral pterygoid

A triangular muscle with two heads that acts as the major protractor of the mandible; also performs ‘side to side’ movement unilaterally.

Vestibule

The horseshoe-shaped space in the oral cavity situated between the lips/cheeks and the gums/teeth.

Hard palate

A bony plate separating the nasal and oral cavities, formed by the palatine processes of the maxillae and the horizontal plates of the palatine bones.

Buccinator muscle

The muscle forming the cheeks, innervated by the buccal branches of the facial nerve ($CN VII$), which keeps food between the teeth during chewing.

Mylohyoid muscle

A suprahyoid muscle that forms the floor of the oral cavity and pulls the larynx forward during swallowing; innervated by the inferior alveolar nerve.

Oropharyngeal triangle

A gap in the pharyngeal wall between the superior and middle constrictors and the mylohyoid, through which the lingual artery, lingual nerve, and hypoglossal nerve pass.

Gag reflex

A protective reflex where stimulation of the glossopharyngeal nerve ($CN IX$) leads to pharyngeal contraction via the vagus nerve ($CN X$).

Foramen cecum of the tongue

A small depression at the apex of the terminal sulcus marking the embryonic site where the thyroid gland invaginated.

Vallate papillae

The largest tongue papillae, totaling $8$ to $12$ in a line anterior to the terminal sulcus, all containing taste buds.

Genioglossus

A large extrinsic tongue muscle arising from the mandibular symphysis that performs protrusion and depression of the tongue.

Hyoglossus

An extrinsic muscle arising from the hyoid bone that depresses and retracts the tongue.

Lingual artery

A branch of the external carotid artery that passes deep to the hyoglossus muscle to supply the tongue and sublingual gland.

Parotid gland

A bilateral salivary gland located between the zygomatic arch and the mandible, with secretions transported by the Stensen duct.

Stensen duct

Arises from the parotid gland, pierces the buccinator, and opens into the oral cavity near the second upper molar.

Submandibular gland

A hook-shaped gland whose deep arm enters the oral cavity proper through a triangular aperture in the mylohyoid muscle.

Wharton’s duct

Also known as the submandibular duct; it is approximately $5\,cm$ long and opens on the sublingual papilla at the base of the lingual frenulum.

Tensor Veli Palatini

A muscle of the soft palate innervated by the mandibular nerve ($V_3$) that tenses the soft palate.

Permanent teeth

A set of $32$ adult teeth, comprising two incisor, one canine, two premolar, and three molar teeth on each side of both arches.

Deciduous teeth

Also known as 'baby' teeth; there are $20$ in total, emerging between six months and two years of age.