G52: Nasal Cavity Flashcards
General function of the nose
respiration, olfactory, filtration, humidify, warm and slow inspired air, receive secretions from sinuses
Root of nose
attached to face
Apex of nose
inferior tip of nose
dorsum of nose
extends from root to apex
the bridge of the nose is composed of what bony structures
nasal bones, frontal processes of maxilla, nasal part of frontal
5 hyaline cartilages forming nose
2- alar, 2-lateral, septum connected via perichondrium and periostium continuity
Bones of nasal septum and cartilage
perpendicular plate of ethmoid, vomer (palatine and maxilla nasal crest) and septal cartilage
CSF rhinorrhea
fracture to ethmoidal cribiform plate due to blow to nose, bony nasal septum pushes into cribiform plate (clear, watery discharge), flow changes with posture changes
Anterior nares and piriform aperture
opens nose to exterior
Opening into the nasopharynx posteriorly
Choanae
Vestibule
dilated portion (where finger inserts), contain skin and course hairs (vibrissae)
Vibrissae
course nose hairs in vestibule, filter foreign matter
Olfactory region of nasal cavity
Superior 1/3 of cavity; olfactory epithelium
Respiratory region of nasal cavity
inferior 2/3 of nasal cavity; respiratory epithelium for warming and moistening air
Medial wall of nasal cavity
smooth nasal septum; vomer, perpendicular plate of ethmoid, septal cartilage covered by mucous membranes
Floor of nasal cavity
palatine process of maxilla and horizontal plate of palatine covered with mucous membranes
Roof of the nasal cavity
frontonasal, ethmoidal, and sphenoidal parts
Lateral wall of nasal cavity
3 longitudinal concha (or turbinate bones) covered with mucous membranes
Superior nasal concha
small, rounded, ethmoid bone
Middle nasal concha
larger, ethmoid bone
Inferior nasal concha
largest, individual bone
Nasal meatus
Opening inferior and lateral to each nasal concha; receives ostium and secretions from parasinuses and nasolacrimal ducts
Superior meatus
receives ostium of posterior ethmoidal sinus
Middle meatus
ethmoidal bulla (elevation) from ostium for the middle ethmoidal sinuses; semilunar hiatus
Semilunar hiatus
ostia for anterior ethmoidal sinus, frontal snus, maxillary sinus
Inferior meatus
ostium for nasolacrimal duct
Sphenoethmoidal recess
ostium for sphenoidal sinus
4 paranasal sinuses
frontal, ethmoidal, sphenoidal, and maxillary; lined with mucous membranes continuous with the nasal cavity
Air cells
fill nasal sinuses - lighten skull, enlarge and change skull shape
Function of sinuses
voice resonance, warm air, lighten skull
Frontal sinus
between outer and inner laminae of frontal bone, drain into semilunar hiatus of middle meatus, posterior to superciliary arches
Ethmoidal sinus
3 sets of of small cavities in the ethmoidal bone
anterior- directly/indirectly to middle meatus
middle - middle meatus
Posterior - superior meatus
Sphenoidal sinus
body of sphenoid, drains to sphenoethmoidal recess
Maxillary sinus
large, entire body of maxilla, drains to middle meatus through semilunar hiatus, prone to infection due to difficulty draining sinus and superior position of ostium
Sinusitis
inflammation and swelling of mucosa of sinus
Blood supply to nasal cavity
Maxillary a -> sphenopalatine a. (posterior lateral nasal and septal branches)-> descending palatine a. -> greater palatine a. (
Opthalmic a. -> anterior and posterior ethmoidal a.
Facial a. -> twigs
Posterior region of nose is supplied by
posterior lateral nasal and posterior septal nasal branches of the sphenopalatine a.
Nasal septum and hard palate are supplied by
greater palatine a. (descending palatine a. -> maxillary a.)
inferior region of nasal cavity
descending palatine a. (maxillary a.)
Anterosuperior region of nasal cavity
posterior and anterior ethmoidal a. (opthalmic a.)
Venous drainage of nasal cavity
sphenopalatine v -> pterygoid plexus
facial, infraorbital, or opthalmic v -> cavernous sinus
Epistaxis
nose bleed, common due to rich vascularization of nasal cavity Kiesselbachs area anastomose of many arteries
Innervation of the olfactory region
Olfactory n. fila (axons) enter foramina of cribiform plate of ethmoid; olfactory bulb over cribiform plate
Innervation of the respiratory region
Trigeminal n.
Opthalmic div -> nasociliary -> anterior ethmoidal n. -> external nasal n.
Maxillary div ->pterygopalatine ganglion -> 1. posterior superior nasal branch (to lateral wall) 2. posterior inferior nasal branch -> greater palatine n. (greater palatine canal) 3.nasopalatine n. (groove of vomer innervates nasal septum enters incisive foramen)
Anosmia
damage to olfactory fila, loss of smell
Pterygopalatine fossa
small triangular space inferior to the apex of the orbit, between pterygoid processes and palatine bone
Pterygopalatine fossa is continuous with the
infratemporal fossa via the pterygomaxillary fissure
Pterygomaxillary fissure
opens laterally from pterygopalatine fossa into the infratemporal fossa
Sphenopalatine foramen
opens medially from pterygopalatine fossa to nasal cavity
greater palatine canal
opens inferiorly to roof of mouth
inferior orbital fissure
opens anteriorly to flood of orbit
Pterygoid canal
opens posteriorly to foramen lecerum
Foramen rotundum
opens posteriorly to the middle cranial fossa
pharyngeal canal
opens posteriorly to the pharynx
Maxillary div of CN 5
enters pterygopalatine fossa through the foramen rotundum
exits via the inferior orbital fissure to become the infraorbital nerve; gives off branches in the fossa
Zygomatic n.
exits the fossa via the inferior orbital fissure to give zygomaticofacial n. and zygomaticotemporal n.
Zygomaticotemporal n.
carries fibers of postganglionic parasympathetic from pterygopalatine ganglion to the lacrimal gland
Greater and Lesser palatine n.
descend to the palate, greater palatine n. -> posterior inferior nasal branches
Posterior superior nasal n.
via sphenopalatine foramen, lateral branches (lateral nasal wall), nasopalatine n. (septum and roof of mouth), pharyngeal nerve via pharyngeal canal
Infraorbital n. gives off
posterior superior alveolar nn., middle and anterior superior alveolar nn. to innervate the maxillary molars, premolars, canines, and incisors
Maxillary sinuses may compress the infraorbital n. branches
causing pain in the upper teeth
pterygopalatine n.
sensory n. from the maxillary div of CN 5 to connect to the pterygopalatine ganglion
Pterygopalatine ganglion
sensory fibers from CN 5-2, postganglionic sympathetic (from deep petrosal- internal carotid plexus- superior cervical ganglion), and preganglionic parasympathetic (CN 7 greater petrosal n. to nerve of pterygoid canal and synapse)
Third portion of the maxillary a. is considered the
terminal branches (post. sup. alveolar a., infraorbital a., ant. sup. alveolar a., sphenopalatine, descending palatine a. (greater and lesser palatine artery))
peripheral organ of olfaction
contained in the nose
contents of pterygopalatine fossa
mxillary div of trigeminal, pterygopalatine ganglion, maxillary a.
Keisselbach’s area
prone to epistaxis due to rich areterial supply and anastomoses