Oral Cavity, Pterygopalatine Fossa, Infratemporal Fossa, and Parotid Gland

Comprehensive review flashcards covering the osteological boundaries, communications, neurovascular contents, and clinical correlations of the Oral Cavity, Pterygopalatine Fossa, Infratemporal Fossa, and Parotid Gland.

Which three cranial bones form the walls of the pterygopalatine fossa?

The palatine bone, maxilla, and sphenoid bone.

Which bone forms the anterior wall of the pterygopalatine fossa?

The maxilla.

Which bone forms the medial wall of the pterygopalatine fossa?

The palatine bone.

Which bone forms both the posterior wall and the roof of the pterygopalatine fossa?

The sphenoid bone.

What anatomical fissure connects the infratemporal fossa medially with the pterygopalatine fossa?

The pterygomaxillary fissure.

What structure forms the posterior margin of the pterygomaxillary fissure?

The lateral pterygoid plate.

What structure forms the anterior margin of the pterygomaxillary fissure?

The posterior aspect of the maxilla.

What foramen provides posterior communication between the middle cranial fossa and the pterygopalatine fossa for the maxillary nerve ($V_2$)?

Foramen rotundum.

What structure is represented by the red pipe cleaner passing through the foramen rotundum in this osteological specimen?

The maxillary nerve ($V_2$).

How is the general shape and location of the infratemporal fossa described?

It is a wedge-shaped cavity situated below and medial to the zygomatic arch.

Is the infratemporal fossa completely enclosed by bone?

No, it is not fully enclosed by bone.

To which space is the roof of the infratemporal fossa open superiorly, lateral to the infratemporal crest?

The temporal fossa.

What highlighted region on the inferior aspect of the skull is shown in purple?

The infratemporal fossa.

What are the two major neurovascular structures for which the pterygopalatine fossa serves as a primary distribution site?

The maxillary nerve ($V_2$) and the terminal part of the maxillary artery.

Which parasympathetic ganglion is located within the pterygopalatine fossa?

The pterygopalatine ganglion.

What two openings allow communication between the pterygopalatine fossa and the middle cranial fossa?

The foramen rotundum and the pterygoid canal.

Through which opening does the pterygopalatine fossa communicate with the floor of the orbit?

The inferior orbital fissure.

Through which opening does the pterygopalatine fossa communicate with the nasal cavity?

The sphenopalatine foramen.

Which canal connects the pterygopalatine fossa to the roof of the oral cavity (palate)?

The palatine canal.

Which canal connects the pterygopalatine fossa with the nasopharynx?

The palatovaginal canal.

What nerve passes through the palatovaginal canal to reach the mucous membranes of the nasopharynx?

The pharyngeal nerve (pharyngeal branch of $V_2$).

Which two major neurovascular bundles descend through the palatine canal?

The greater and lesser palatine nerves and the descending palatine artery.

Which artery traverses the sphenopalatine foramen to supply the nasal cavity?

The sphenopalatine artery.

Which nerves pass from the pterygopalatine fossa into the floor of the orbit via the inferior orbital fissure?

The infra-orbital nerve and zygomatic nerve.

Where does the posterior opening of the bony pterygoid canal open into the middle cranial fossa?

Anterior inferior to the internal carotid artery as the vessel enters the cranial cavity through the carotid canal.

What fills the foramen lacerum immediately adjacent to the posterior opening of the pterygoid canal?

Cartilage filling foramen lacerum.

Between the foramen rotundum and the pterygoid canal, which opening is located more medial and inferior on the posterior wall of the pterygopalatine fossa?

The pterygoid canal (anterior opening).

Between the foramen rotundum and the pterygoid canal, which opening is located more lateral and superior?

The foramen rotundum.

Which cranial nerve branch gives rise to the greater petrosal nerve?

The facial nerve ($\text{CN VII}$).

What functional type of autonomic nerve fibers are conveyed by the greater petrosal nerve?

Preganglionic (presynaptic) parasympathetic fibers.

From which autonomic plexus does the deep petrosal nerve arise?

The internal carotid plexus.

What functional type of autonomic nerve fibers are conveyed by the deep petrosal nerve?

Postganglionic sympathetic fibers.

The union of which two nerves in the middle cranial fossa forms the nerve of the pterygoid canal?

The greater petrosal nerve and the deep petrosal nerve.

What is the historical eponym for the nerve of the pterygoid canal?

The Vidian nerve.

Where do the postganglionic sympathetic fibers of the deep petrosal nerve originate?

In the superior cervical sympathetic ganglion in the neck.

From which spinal cord segment do the preganglionic sympathetic fibers originate that synapse in the superior cervical ganglion for distribution to the head?

The $T_1$ spinal cord level (spinal nerve).

Under what name do sympathetic fibers leave the superior cervical sympathetic ganglion to travel along the internal carotid artery?

The internal carotid nerve.

Do the sympathetic fibers passing through the nerve of the pterygoid canal synapse in the pterygopalatine ganglion?

No, they pass through the pterygopalatine ganglion without synapsing.

Do the preganglionic parasympathetic fibers carried by the greater petrosal nerve synapse in the pterygopalatine ganglion?

Yes, they synapse with cell bodies of postganglionic parasympathetic neurons in the pterygopalatine ganglion.

Which glands receive parasympathetic secretomotor innervation via the greater petrosal nerve pathway?

All glands above the oral fissure, including mucous glands in the nasal cavity, salivary glands in the upper half of the oral cavity, and the lacrimal gland in the orbit.

What type of special sensory fibers does the greater petrosal nerve carry from the soft palate?

Special afferent ($\text{SA}$) / taste fibers.

Through which specific palatine nerve do taste fibers from the soft palate travel before joining the greater petrosal nerve?

The lesser palatine nerve.

What clinical manifestation occurs following a lesion anywhere along the parasympathetic pathway of the facial nerve ($\text{CN VII}$) to the lacrimal gland?

"Dry eye" in the affected eye.

Which division of the trigeminal nerve ultimately conveys postganglionic parasympathetic fibers directly into the lacrimal gland?

The ophthalmic nerve ($V_1$, specifically via its lacrimal nerve branch).

How do postganglionic parasympathetic fibers from the pterygopalatine ganglion reach the lacrimal nerve of $V_1$?

Via the zygomatic nerve (branch of $V_2$) and its communicating branch to the lacrimal nerve.

What groove and canal does the maxillary nerve ($V_2$) enter after passing through the pterygopalatine fossa?

The infraorbital groove and infraorbital canal in the floor of the orbit.

Through which foramen on the anterior maxilla does the infra-orbital nerve emerge onto the face?

The infraorbital foramen.

Which direct branches arise from the maxillary nerve ($V_2$) while it resides within the pterygopalatine fossa?

The zygomatic nerve, posterior superior alveolar nerve, and two ganglionic branches.

From which surface of the maxillary nerve do the two ganglionic branches arise to suspend the pterygopalatine ganglion?

From its inferior surface.

What are the two cutaneous terminal branches of the zygomatic nerve?

The zygomaticotemporal branch and zygomaticofacial branch.

Which teeth are innervated by the posterior superior alveolar nerve?

The maxillary molar teeth.

Which paranasal sinus receives sensory innervation from the posterior superior alveolar nerve?

The maxillary sinus.

Which nerve arising from the infraorbital canal supplies the maxillary premolar teeth?

The middle superior alveolar nerve.

Which nerve arising from the infraorbital canal supplies the maxillary canine and incisor teeth?

The anterior superior alveolar nerve.

What are the three terminal facial branches of the infra-orbital nerve after emerging from the infraorbital foramen?

The inferior palpebral branch, external nasal branch, and superior labial branch.

What region is supplied by the inferior palpebral branch of the infra-orbital nerve?

The lower eyelid.

What region is supplied by the superior labial branch of the infra-orbital nerve?

The skin and mucous membranes of the upper lip.

Which nerve passes forward along the roof of the oral cavity to supply the mucosa and glands of the hard palate?

The greater palatine nerve.

How far anteriorly does the distribution of the greater palatine nerve extend on the hard palate?

Almost as far forward as the incisor teeth.

What specific branches arise from the greater palatine nerve while it is descending within the palatine canal?

The posterior inferior nasal nerves.

Which nerve passes posteriorly upon emerging from the lesser palatine foramina to supply the soft palate?

The lesser palatine nerve.

What structures on the hard palate are innervated by the greater palatine nerve?

The mucosa and glands of the hard palate and the adjacent lingual gingiva.

Which nerve supplies the anterior hard palate and lingual gingiva behind the incisor teeth after exiting the incisive fossa?

The nasopalatine nerve.

What bony septum does the nasopalatine nerve traverse before passing into the incisive canal?

The nasal septum.

List the six branches of the maxillary artery originating in or around the pterygopalatine fossa.

The posterior superior alveolar artery, infra-orbital artery, greater palatine artery, pharyngeal artery, sphenopalatine artery, and artery of the pterygoid canal.

Which branch of the maxillary artery passes through the inferior orbital fissure onto the orbital floor?

The infra-orbital artery.

Which branch of the maxillary artery traverses the palatine canal to reach the hard palate?

The greater palatine artery (descending palatine artery).

Which branch of the maxillary artery passes through the palatovaginal canal?

The pharyngeal artery.

Which branch of the maxillary artery supplies the nasal cavity by passing through the sphenopalatine foramen?

The sphenopalatine artery.

Which branch of the maxillary artery travels alongside the Vidian nerve through the pterygoid canal?

The artery of the pterygoid canal.

Which branch of the maxillary artery supplies the maxillary molars, premolars, and the lining of the maxillary antrum?

The posterior superior alveolar artery.

What branch of the descending palatine artery branches off to supply the soft palate?

The lesser palatine artery.

What arterial branch of the greater palatine artery ascends through the incisive canal to anastomose with septal branches?

The septal part of the greater palatine artery.

Into which primary vein does the pterygoid plexus of veins drain?

The maxillary vein.

The union of the maxillary vein and the superficial temporal vein forms which vessel?

The retromandibular vein.

How does the pterygoid venous plexus connect superiorly with the cavernous sinus?

Via small communicating emissary veins passing through small emissary foramina and the foramen ovale in the base of the skull.

What is the clinical significance of the emissary venous connections between the pterygoid plexus and cavernous sinus?

Infections originating in the teeth can track into the cranial cavity through these small emissary veins.

Which vein connects the pterygoid plexus anteriorly to the facial vein?

The deep facial vein.

Which orbital vein can drain directly into the pterygoid plexus through the inferior orbital fissure?

The inferior ophthalmic vein.

What vascular network is located in the infratemporal fossa around the pterygoid muscles?

The pterygoid plexus of veins (pterygoid venous plexus).

What are the two anatomical subdivisions of the oral cavity?

The outer oral vestibule and the inner oral cavity proper.

Where is the oral vestibule located?

Between the dental arches and the deep surfaces of the cheeks and lips (or oral fissure).

What structures enclose the oral cavity proper?

The dental arches (teeth and alveolar ridges).

What are the three primary functions of the oral cavity listed in the notes?

1. An inlet for the digestive system, 2. Manipulates sounds produced by the larynx leading to speech, and 3. Aids in breathing.

What muscle forms the primary posterior/inferior border and floor of the oral cavity gateway?

The mylohyoid muscle.

Which two muscles provide continuity between the lateral walls of the oral and pharyngeal cavities?

The buccinator and superior constrictor muscles of the pharynx.

What fibrous band connects the buccinator muscle to the superior constrictor muscle?

The pterygomandibular raphe.

Which muscles define the triangular aperture through which structures pass into the floor of the oral cavity?

The mylohyoid, superior constrictor, and middle constrictor muscles of the pharynx.

What major anatomical organ and its associated neurovasculature pass through the triangular aperture in the oral floor?

Most structures associated with the tongue.

What small depression is located at the apex of the V-shaped terminal sulcus on the dorsum of the tongue?

The foramen cecum of the tongue.

What does the foramen cecum mark embryologically?

The site where the epithelium invaginated to form the thyroid gland.

What embryonic remnant may persist connecting the foramen cecum to the thyroid gland in the neck?

A thyroglossal duct.

What V-shaped groove separates the anterior two-thirds of the tongue from the posterior one-third?

The terminal sulcus (sulcus terminalis).

What proportion of the tongue is formed by the oral part anterior to the terminal sulcus?

The anterior two-thirds.

What proportion of the tongue is formed by the pharyngeal part posterior to the terminal sulcus?

The posterior one-third.

How are filiform papillae described morphologically?

Small cone-shaped projections of mucosa that end in one or more points.

How are fungiform papillae described, and where are they primarily concentrated?

They are rounder in shape and larger than filiform papillae, concentrated along the margins of the tongue.

How many circumvallate (vallate) papillae are present on the human tongue?

Only about $8\text{ to }12$ vallate papillae.

Where are the circumvallate (vallate) papillae located on the tongue?

In a single V-shaped line immediately anterior to the terminal sulcus of the tongue.

How are circumvallate (vallate) papillae characterized structurally?

As blunt-ended cylindrical papillae invaginations.