Anatomy: Nasal and Oral Cavity

Nasal bones

Paired facial bones that project thin anteriorly to form the bridge of the nose, making them prone to fracture.

Septal cartilage

The anterior cartilaginous part of the nasal septum that articulates with the vomer and perpendicular plate of the ethmoid bone.

Alar cartilage

A pliable cartilage forming the lower lateral portion and tip of the external nose surrounding the nares.

Perpendicular plate of ethmoid bone

A thin, vertical bony plate extending inferiorly from the cribriform plate to form the posterosuperior portion of the medial nasal septum.

Vomer

An unpaired midline bone forming the posteroinferior portion of the medial nasal septum.

Palatine process of maxilla

The horizontal bony shelf of the maxilla forming the anterior two-thirds of the floor of the nasal cavity and hard palate.

Horizontal plate of palatine bone

The bony plate forming the posterior one-third of the hard palate and floor of the nasal cavity.

Cribriform plate of ethmoid bone

The perforated horizontal apex of the nasal cavity transmitting olfactory nerve (CN I) fibers into the anterior cranial fossa.

Superior and middle conchae

Scroll-like bony projections extending inferomedially from the ethmoid bone along the lateral nasal wall.

Inferior concha

An independent bony shelf projecting inferomedially along the lateral nasal wall.

Sphenopalatine foramen

A bony aperture on the lateral nasal wall transmitting the sphenopalatine artery and branches of CN V2 into the nasal cavity.

Incisive canal

An anatomical canal in the anterior hard palate transmitting the nasopalatine nerve and greater palatine artery.

Nasal cavity

Paired triangular spaces extending from the nares anteriorly to the nasopharynx posteriorly via the choanae.

Olfactory area of nasal cavity

The superior one-third of the nasal cavity innervated by olfactory nerves (CN I) for special sensation.

Respiratory area of nasal cavity

The inferior two-thirds of the nasal cavity lined with mucosa that filters, heats, and humidifies inspired air.

Concha

Scroll-like bony shelves projecting inferomedially into the nasal cavity to create air turbulence, warming and humidifying inspired air.

Meatus

An air passageway located beneath and medial to each corresponding concha into which paranasal sinuses and nasal ducts drain.

Superior meatus

The air passage beneath the superior concha into which posterior ethmoidal air cells drain.

Middle meatus

The air passage beneath the middle concha containing the semilunar hiatus and ethmoidal bulla, receiving drainage from the frontal, maxillary, and anterior/middle ethmoidal sinuses.

Inferior meatus

The air passage beneath the inferior concha containing the orifice of the nasolacrimal duct.

Sphenoethmoid recess

A small anatomical space located superoposterior to the superior concha into which the sphenoid sinus drains.

Semilunar hiatus

A curved groove in the middle nasal meatus through which the frontal, maxillary, and anterior ethmoidal sinuses drain.

Ethmoidal bulla

An elevation in the middle nasal meatus formed by underlying middle ethmoidal air cells.

Paranasal sinuses

Air-filled extensions of the nasal cavity into the frontal, ethmoid, sphenoid, and maxillary bones that reduce skull weight and increase voice resonance.

Frontal sinus

A paranasal sinus located in the frontal bone that drains into the middle nasal meatus.

Ethmoid sinus (air cells)

Interconnected air cells located between the nasal cavity and orbit, divided into anterior and middle groups (draining into the middle meatus) and a posterior group (draining into the superior meatus).

Sphenoid sinus

A paranasal sinus situated within the body of the sphenoid bone adjacent to the optic nerve, pituitary, internal carotid artery, and cavernous sinus, draining into the sphenoethmoid recess.

Maxillary sinus

The largest paranasal sinus, bounded superiorly by the floor of the orbit and inferiorly by the maxillary alveolar process, draining into the middle meatus.

Hard palate

The rigid anterior two-thirds of the palate formed by the palatine processes of the maxillae and horizontal plates of the palatine bones, separating the oral cavity from the nasal cavity.

Soft palate

The movable posterior one-third of the palate composed of muscle fibers, aponeurosis, and mucosa that acts during swallowing to separate the oral cavity and oropharynx from the nasopharynx.

Uvula

A conical muscular projection hanging from the curved posteroinferior free margin of the soft palate.

Palatoglossal arch

An anterior mucosal fold extending from the soft palate to the side of the tongue that marks the posterior boundary of the oral cavity proper.

Palatopharyngeal arch

A posterior mucosal fold extending from the soft palate to the lateral wall of the pharynx.

Palatine tonsil

A mass of lymphoid tissue located in the tonsillar fossa between the palatoglossal and palatopharyngeal arches.

Tensor veli palatini

A muscle innervated by a branch of the mandibular nerve (CN V3) that tenses the soft palate and opens the auditory tube during swallowing and yawning.

Levator veli palatini

A muscle innervated by pharyngeal branches of the vagus nerve (CN X) that elevates the soft palate during swallowing and yawning.

Palatoglossus

A muscle innervated by pharyngeal branches of the vagus nerve (CN X) that helps elevate the posterior tongue and narrows the oropharyngeal isthmus.

Musculus uvulae

A muscle innervated by pharyngeal branches of the vagus nerve (CN X) that shortens and pulls the uvula superiorly.

Genioglossus

The primary muscle mass of the tongue innervated by the hypoglossal nerve (CN XII) that depresses and protrudes the tongue bilaterally, or deviates it to the opposite side unilaterally.

Hyoglossus

A muscle innervated by the hypoglossal nerve (CN XII) that depresses the tongue during digestion.

Styloglossus

A muscle innervated by the hypoglossal nerve (CN XII) that retrudes (retracts) and elevates the tongue to propel food into the oropharynx.

Intrinsic muscles of the tongue

Internal tongue muscles innervated by the hypoglossal nerve (CN XII) that alter the shape of the tongue by curling or flattening it.

Oral vestibule

The space of the oral cavity situated between the lips/cheeks externally and the teeth/gums internally.

Oral cavity proper

The internal space of the oral cavity bounded anteriorly and laterally by the dental arches and extending posteriorly to the palatoglossal arch.

Terminal sulcus

A V-shaped groove on the dorsum of the tongue that separates the anterior two-thirds (body) from the posterior one-third (root).

Lingual tonsil

Lymphoid tissue located on the posterior one-third (root) of the tongue.

Sublingual carunculae

Papillae located on either side of the lingual frenulum containing the openings of the submandibular ducts.

Frenulum of tongue

A midline mucosal fold connecting the inferior surface of the tongue to the floor of the mouth.

Submandibular gland

A salivary gland located beneath the floor of the mouth that drains via the submandibular duct into the sublingual caruncles.

Sublingual gland

A salivary gland located deep to the mucosa of the floor of the mouth inferior to the tongue.

Nasopalatine nerve

A branch of the maxillary nerve (CN V2) passing through the incisive canal to provide sensory innervation to the pre-maxillary hard palate.

Greater palatine nerve

A branch of the maxillary nerve (CN V2) providing sensory innervation to the hard palate.

Lesser palatine nerve

A branch of the maxillary nerve (CN V2) providing sensory innervation to the soft palate.

Lingual nerve (CN V3)

A branch of the mandibular nerve providing general sensation to the anterior two-thirds of the tongue.

Chorda tympani (CN VII)

A nerve branch riding on the lingual nerve that carries special sensory taste fibers from the anterior two-thirds of the tongue and preganglionic parasympathetic fibers to the submandibular ganglion.

Glossopharyngeal nerve (CN IX)

A cranial nerve providing general sensation and special sensory taste to the posterior one-third of the tongue.

Kiesselbach area

An arterial plexus located on the anterior nasal septum rich in anastomosing vessels, making it a common site for epistaxis.

Sphenopalatine artery

A major branch of the maxillary artery traversing the sphenopalatine foramen to supply the lateral wall and septum of the nasal cavity.

Greater palatine artery

A branch of the maxillary artery supplying the hard palate and nasal septum via the incisive canal.

Lingual artery

A branch of the external carotid artery that divides into dorsal lingual, deep lingual, and sublingual arteries to supply the tongue and sublingual gland.

Epistaxis

Nosebleeding commonly originating from the rich vascular network of the anterior nasal septum.

Deviated nasal septum

Displacement of the nasal septum from the midline toward the lateral wall, which can cause airway obstruction and sleeping issues such as snoring.

Injury to pharyngeal branches of vagus nerve

A nerve lesion causing dysphagia, drooping of the soft palate on the affected side, and deviation of the uvula toward the unaffected side.

Injury to hypoglossal nerve (CN XII)

A nerve lesion causing paralysis of the genioglossus muscle on one side, resulting in tongue deviation toward the affected side during protrusion