HNNS Anatomy - Nasal cavity and Paranasal air sinuses Flashcards
5 functions of the nasal cavities.
Respiration Olfaction Filtration of dust Humidification of air Drainage of paranasal air sinuses
Define the upper and lower respiratory tracts.
Upper = nasal cavities Lower = Larynx, trachea, bronchi, bronchioles, alveoli
Bones that form the nose?
Nasal bones
Frontal process of maxillae
Nasal part of frontal bone
Bones that form the roof, septum and floor of the nasal cavity?
Roof = Frontonasal, Ethmoid and Sphenoid bones Septum= Perpendicular plate of ethmoid bone, Vomer, Septal cartilage Floor = Hard palate: Palatine process of maxilla, horizontal plate of palatine bone
Structure of the lateral walls of the nasal cavities?
3 curvature plates = concha/ turbinates with Meatus* underneath for drainage of paranasal sinuses and nasolacrimal ducts
*Superior, Middle and Inferior turbinate with associated meatus
Define the epithelium types of the nasal cavity.
Upper = Olfactory epithelium
Most = Pseudostratified ciliated epithelium
Nerve supply of nasal cavity?
Upper = CN I (olfactory nerve)
Rest = Br. of Maxillary nerve (V2) and Ophthalmic nerve (V1)
Blood supply of nasal cavity?
1) Maxillary artery (ECA) branches: Sphenopalatine*** (lateral wall) and greater palatine arteries (hard palate)
2) Facial artery (ECA) branches: Lateral nasal (lateral wall) and superior labial arteries (nasal septum)
3) Opthalmic artery (ICA) branches: Anterior and Posterior ethmoidal arteries (roof)
Venous drainage of nasal cavity?
Pterygoid plexus
Facial vein
Infraorbital vein
Ophthalmic vein
Define epistaxis and explain where it occurs?
Nose bleed, caused by trauma, infection ,hypertension
At Kiesselbach area at anterior 1/3 of nose
List 5 structures that infection of the nasal cavities may spread to?
Anterior cranial fossa Middle ear (via auditory tube) Paranasal sinuses Lacrimal apparatus Conjunctiva
Explain the anatomical structures affected to cause CSF rhinorrhea?
Fracture extending to roof of nasal cavity and Cribiform plate of ethmoid bone
» Tear meninges and release CSF
Define the paranasal sinuses?
Frontal
Maxillary
Ethmoid
Sphenoid
Define the site of drainage of the paranasal sinuses.
Frontal = Frontaonasal duct >> Hiatus Semilunaris Maxillary = Posterior Middle meatus via Infundibulum Sphenoid = Sphenoethmoidal recess >> opening of sphenoid sinus
Ethmoid:
Anterior group = Infundibulum + Anterior middle meatus
Middle = Middle meatus above bulla ethmoidalis
Posterior = Superior meatus
Which is the most commonly infected paranasal sinus and why?
Maxillary
Opening/ Ostium to this sinus is high up the nasal cavity. Inflammation of the opening canal can easily obstruct drainage and retain mucus
Define the 4 connections that the Pterygopalatine fossa makes with other cranial structures.
1) Laterally = infratemporal fossa through pterygomaxillary fissure
2) Medial = Nasal cavity through sphenopalatine foramen
3) Anterior = Orbit through Inferior orbital fissure
4) Posterior = Middle cranial fossa through foramen rotundum and pterygoid canal
Content of pterygopalatine fossa?
Maxillary branch of Trigeminal nerve (V2)
Sphenopalatine Artery (through sphenopalatine foramen to nasal cavity) + vein (drain to pterygoid plexus)
Pterygopalatine ganglion
List 4 main branches of the maxillary nerve (V2)?
Meningeal branches
Zygomatic branches: zygomaticotemporal and zygomaticofacial
pterygopalatine nerves
Alveolar nerves: anterior, middle and posterior branches
What is supplied by the zygomatic branches of V2? ***
Zygomaticotemporal and Zygomaticofacial nerves supply temple and cheek skin
Zygomaticotemporal carries parasym. fibers to lacrimal gland by relaying to lacrimal nerve through Superior orbital fissure
What is carried by the ganglionic branches of the V2?
Sensory fibers from the nose, palate and pharynx that pass through the pterygopalatine ganglion
Parasympathetic branches to the lacrimal gland
What is supplied by the alveolar nerves branching of V2?
Gum, cheek, upper teeth, maxillary sinus
Overall function and branches of the pterygopalatine ganglion?
Secretory motor to lacrimal and nasal glands, Parasympathetic only
Orbital branches»_space; orbit via inf. orbital fissure
Greater and Lesser palatine nerves»_space; palate, tonsil, nasal cavity
Nasal branches»_space; Nasal cavity
Pharyngeal branches»_space; Roof of nasopharynx
Nasopalatine branch»_space; Incisive foramen
What tissue forms the flares of the nose?
Alar fibrofatty tissue
Blood supply of paranasal sinuses? Nerve supply?
Opthalmic artery (ICA) + Maxillary artery (ECA)
V1 + V2
Define the openings at the hiatus semilunaris?
Anterior opening = Anterior ethmoid sinus
Posterior opening = Maxillary sinus
Define the parasym and sym nerve input into the Pterygopalatine ganglion? Output branches? **
Parasym: CN7 (through foramen lacerum)»_space; Greater petrosal nerve
Sym: T1-T2 sympathetic chain»_space; Deep petrosal nerve
Greater and Deep petrosal nerves merge to form Vidian nerve through Pterygoid canal to reach pterygopalatine ganglion
Pharyngeal branch
Greater and Lesser palatine nerves
Nasal branch
Nasopalatine nerve
Define the connection between the Maxillary nerve and the Pteygopalatine ganglion?
Ganglionic branch of V2/ Pterygopalatine nerve
Trace the parasympathetic innervation of the lacrimal glands?
CN7»_space; foramen lacerum»_space; Greater petrosal nerve»_space; Vidian nerve»_space; Pterygopalatine ganglion»_space; Gnalgionic branch of Maxillary nerve»_space; Maxillary nerve»_space; Zygomaticotemporal nerve»_space; Superior orbital fissure»_space; Lacrimal nerve of V1»_space; Lacrimal gland
Which branch of the Pterygopalatine ganglion carries special sensory fibers?
Greater palatine nerve»_space; Taste
