The Nose and Paranasal Sinuses

Vocabulary practice flashcards covering the anatomical framework, boundaries, paranasal sinuses, blood supply, innervation, autonomic pathways, and lymphatic drainage of the human nose.

External Nose

The anterior facial structure consisting of a bony and cartilaginous framework closely overlaid by skin and fibrofatty tissues.

Bony Pyramid of the External Nose

The bony support structure of the external nasal framework formed by the two nasal bones and the frontal processes of the maxilla.

Ala Nasi

The rounded, mobile lateral margin of the external nose composed solely of fatty tissue at its lower free edge.

Primary Muscles of the External Nose

Facial muscles innervated by the facial nerve, comprising the nasalis (compressor naris), dilator naris, and levator labii superioris alaeque nasi.

Nerve Supply of the External Nose

Innervation provided by three main branches: the infratrochlear and external nasal branches of the ophthalmic nerve, and the infraorbital branch of the maxillary nerve.

Arterial Supply of the External Nose

Blood supply derived from the dorsal nasal and external nasal branches of the ophthalmic artery, the infraorbital branch of the maxillary artery, and the lateral nasal and angular branches of the facial artery.

Roof of the Nasal Cavity

Boundary formed anteriorly by the frontal and nasal bones, in the middle by the cribriform plate of the ethmoid, and posteriorly by the undersurface of the sphenoid body, ala of the vomer, and sphenoidal process of the palatine bone.

Floor of the Nasal Cavity

Boundary formed by the palatine process of the maxilla (anterior $\frac{3}{4}$) and the horizontal plate of the palatine bone (posterior $\frac{1}{4}$).

Medial Wall of the Nasal Cavity (Nasal Septum)

The osteocartilaginous partition formed by the perpendicular plate of the ethmoid bone above, the vomer below, and the septal cartilage in between.

Uncinate Process of the Ethmoid Bone

A sickle-shaped bony projection located on the lateral nasal wall that protects the opening of the maxillary sinus.

Ethmoidal Labyrinth

A box-shaped bony structure situated between the nasal septum and the lateral nasal wall that contains the ethmoid air cells or sinuses.

Lamina Papyracea

The thin bony plate of the ethmoid bone forming the medial wall of the orbit, separating the orbit from the ethmoid sinuses.

Superior Nasal Meatus

The nasal passage lying between the superior and middle nasal conchae that receives the openings of the posterior ethmoidal sinuses.

Sphenoethmoidal Recess

The space situated above and behind the superior nasal concha that receives the opening of the sphenoidal air sinus.

Hiatus Semilunaris

A semicircular groove in the middle nasal meatus that receives the opening of the frontal sinus (via the infundibulum), middle ethmoidal sinus, and maxillary sinus.

Bulla Ethmoidalis

A prominence on the lateral wall of the middle meatus formed by underlying middle ethmoidal cells, which receives the opening of the middle ethmoidal sinus.

Inferior Nasal Meatus

The nasal passage located below the inferior nasal concha that receives the opening of the nasolacrimal duct.

Paranasal Air Sinuses

Four pairs of air cavities (frontal, ethmoidal, sphenoidal, and maxillary) lined by respiratory mucosa with mucous glands and goblet cells, functioning to lighten the skull and add resonance to the voice.

Frontal Air Sinus

A paranasal sinus opening into the infundibulum of the middle meatus via the frontonasal duct, supplied by the supratrochlear and supraorbital vessels.

Ethmoidal Air Sinuses

Sinuses occupying the ethmoidal labyrinth divided into three groups: anterior (opening into hiatus semilunaris), middle (opening into bulla ethmoidalis), and posterior (opening into superior meatus); supplied by anterior and posterior ethmoidal vessels.

Sphenoidal Air Sinus

A sinus occupying the body of the sphenoid bone that opens into the sphenoethmoidal recess and is supplied by the posterior ethmoidal vessels.

Maxillary Air Sinus

The largest paranasal sinus, occupying the body of the maxilla and opening into the hiatus semilunaris, supplied by the infraorbital vessels.

Olfactory Mucosa

Specialized sensory mucosa covering the roof and upper parts of the medial and lateral nasal walls, containing olfactory receptor cells whose axons form the olfactory nerves.

Respiratory Mucosa

Ciliated pseudostratified epithelium containing mucous glands and goblet cells covering the lower and remaining parts of the nasal cavity, responsible for warming, humidifying, and filtering air.

Sphenopalatine Artery

A branch of the maxillary artery entering via the sphenopalatine foramen to supply most of the lateral nasal wall; the predominant artery implicated in primary refractory epistaxis.

Kiesselbach's Plexus (Little's Area)

An anteroinferior region of the nasal septum where septal branches of the anterior ethmoidal, sphenopalatine, superior labial, and greater palatine arteries anastomose; the most frequent site of epistaxis.

Danger Triangle of the Face

The facial zone connecting the nose and upper lip to intracranial venous sinuses via valveless veins that drain into the facial vein and cavernous sinus, providing a route for retrograde spread of infection.

Venous Drainage of the Nose

Venous network draining into the sphenopalatine vein (maxillary vein), facial vein, ophthalmic veins (cavernous sinus), and the superior sagittal sinus via emissary veins.

Sphenopalatine Ganglion (Pterygopalatine Ganglion)

The largest parasympathetic ganglion, located in the pterygopalatine fossa anterior to the pterygoid canal; functionally linked to CN VII and anatomically suspended from the maxillary nerve (CN V2).

Nerve of the Pterygoid Canal (Vidian Nerve)

A nerve formed in the foramen lacerum by the union of the greater petrosal nerve and deep petrosal nerve, traversing the pterygoid canal to reach the sphenopalatine ganglion.

Greater Petrosal Nerve

The parasympathetic root of the sphenopalatine ganglion, originating from the superior salivatory nucleus and branching from the facial nerve (CN VII).

Deep Petrosal Nerve

The sympathetic root of the sphenopalatine ganglion, comprising postganglionic fibers from the superior cervical sympathetic ganglion running in the internal carotid plexus.

Secretomotor Distribution of the Sphenopalatine Ganglion

Postganglionic parasympathetic distribution supplying the lacrimal gland (via zygomatic branch of V2), nasal glands (via nasal branches), and palatine and pharyngeal glands (via palatine and pharyngeal branches).

Nasopalatine Nerve

A branch of the sphenopalatine ganglion that supplies the nasal septum, enters the incisive canal, and innervates the mucous membrane of the anterior hard palate.

Lymphatic Drainage of Anterior Sinuses

Lymphatic drainage pathway from the frontal, anterior ethmoidal, and anterior maxillary sinuses to the submandibular lymph nodes.

Lymphatic Drainage of Posterior Sinuses

Lymphatic drainage pathway from the posterior ethmoidal, sphenoidal, and posterior maxillary sinuses to the retropharyngeal and superior deep cervical lymph nodes.