Nasal Cavity and Paranasal sinuses Flashcards
what are boundaries of maxillary sinus?
- within maxilla bone; largest of all air sinuses
- relationships:
superior= orbit
medial= nasal cavity
inferior = maxillary teeth
ant/lateral = cheek
post = pterygopalatine fossa
where does maxillary drain? innervation?
drains to semilunar hiatus within middle nasal meatus (this drains upwards, thus this is the most susceptible to infection must completely fill before it can drain)
- innervated by branches of V2
where is frontal sinus?
within the frontal bone, superior tosuperciliary arches and nasal bones
cranial cavity = post/superior
nasal cavity/orbit = inferior
where does frontal sinus drain? innervation?
opens via frontonasal duct to semilunar hiatus within the middle nasal meatus
innervated by V1
where is sphenoidal sinus?
within body of sphenoid bone
superior = cranial cavity
lateral = cavernous sinus/cranial cavity
inferior/ant = nasopharynx/nasal cavity
where does sphenoidal sinus drain to? innervation?
opens to sphenoethmoidal recess
innervated by V2
ethmoidal sinus location?
- within ethmoidal bone
- contains anterior, middle and posterior air cells
superior = cranial cavity
middle/inferrior = nasal cavity
lateral = orbit
where does ant air cells drain?
semilunar hiatus of middle nasal meatus
where do middle air cells drain?
ehtmoidal bulla in middle nasal meatus
where do posterior air cells drain?
superior nasal meatus
innervation of ethmoidal sinuses?
V1
Sinusitis? most susceptible?
- infection and inflammation of paranasal sinuses
- can be detected through transillumination of sinuses
- can spread to surrounding structures: eye, optic n, (optic neuritis), teeth, brain/meninges
- infections of maxillary teeth can spread to maxillary air sinus
- **maxillary sinus is most susceptible to infection due to drainage upwards. the ostia of maxillary sinuses are located in upper wall of sinus.
what complications can result from sinusitis?
periorbital cellulitis
subperiosteal abscess
orbital abscess
optic neuritis
meningitis subdural empyema epidural abscess intracerebral absvess cavernous sinus thrombosis
nares
external openings of nose
what makes up roof of nasal cavities?
roof: mostly made of ethmoid bone (CN I passes directly under olfactory epithelium)
oral cavity)
lateral wall boundaries?
lateral wall:
- ethmoid bone: superior and middle concha
- inferior concha
- maxilla
- palatine
- lacrimal bone
floor of nasal cavity?
floor:
- palatine and maxilla (seperates nasal cavity, forms the hard palate)
anterior wall of nasal cavity?
nasal cartilages, nasal bone
- nares are ant. openings of nasal cavity; lead to skin lined vestibule which contains vibrissae, hair cells which filter incoming air
posterior boundary of nasal cavity?
open to nasopharnynx via choanae
medial wall of nasal septum?
- perpendibular plate of ethmoid bone (superior)
- vomer bone (posterior)
- nasal cartilages
note: a deviated septum can sometimes be so severe that it affects breathing and has to be corrected surgically.
nasal mucosa: 2 types?
- respiratory epithelium lines bulk of nasal cavity; rich in blood vessels and mucous glands to warm air as it passes through the cavity
- olfactory epithelium lines superior-posterior portion of cavity; contains CN I
Rhinitis
inflammation of nasal mucosa
- infection can spread to:
- anterior cranial fossa via cribiform plate
- nasopharynx
- middle ear via pharyngotympanic tube
- lacrimal apparatus and conjunctiva via nasolacrimal duct
- paranasal sinuses
sphenoethmoidal recess
- area posterior/superior to superior concha
- contains opening for sphenoidal sinus
superior nasal meatus
- beneath superior concha
- contains opening for posterior ethmoidal sinus
middle nasal meatus
- beneath middle concha
- contains bulla ethmoidalis (where middle ethmoidal air cells drain)
- contains semiluanar hiatus (where anterior ethmoidal air cells, frontal sinus and maxillary sinus drain to)
inferior nasal meatus
- lies beneath inferior concha
- contains opening for nasolacrimal duct
what does internal carotid artery supply?
- anterior and posterior ethmoidal aa (branches from opthalmic)
- these provide septal and lateral nasal branches to the ethmoid sinuses and external nose.
what does external carotid artery supply?
Maxillary artery gives off:
- sphenopalatine artery ***(enters nasal cavity via sphenopalatine foramen, gives lateral nasal and septal branches)
- greater palatine artery (enters nasal cavity via incisive canal, provides nasal septal branches).
Facial artery:
3. superior labial artery, provides septal branches
- sphenopalatine is greatest supplier
Kiesselbach area:
anastamoses between greater palatine, anterior ethmoidal, sphenopalatine a, facial aa.
located on anterior portion of nasal septum - can stop nose bleeds if compressed
venous drainage of nasal cavity?
submucosal venous plexus drains to maxillary, facial and opthalmic vv. –> pterygoid plexus and cavernous sinus to reach internal jugular v.
SVA innervation to nose?
Olfactory nerve - CN I
- bipolar neurons composing CN I are located in superior portion of the nasal cavity epithelium, fiber processes of CN I pass through cribiform plate to synapse in the olfactory bulb of the brain
- olfactory bulb is an extension of the forebrain (telencephalon); thus CN I synapses directly within the forebrain
what GSA innervation is provided to nasal area?
V1 - opthalmic n - provides anterior nasal cavity,frontal sinus and ethmoid sinus
V2- Maxillary n - provides nasal cavity, maxillary sinus, and sphenoid sinus
how does opthalmic n. enter nasal area? branches?
- opthalmic branch of CN V enters orbit via superior orbital fissure
1. supraorbital and supratrochlear n: frontal sinus
2. posterior ethmoidal/anterior n: ehtmoid sinus and anterior nasal cavity
how does maxillary n. enter?
the maxillary branch of CN V enters pterygopalatine fossa via foramen rotundum
Branches:
- infraortibal, posterior superior alveolar nn.
- nasopalatine n
- posterior superior/inferior lateral nasal nn.
- pharyngeal n.
what nerve supplies GSA to maxillary sinus and external nose?
infraorbital and posterior superior alveolar nn - V2
GSA to nasal septum
V2- nasopalatine n.
GSA to lateral nasal wall?
V2- posterior superior/inferior lateral nasal nn.
GSA to sphenoid sinus
phrayngeal n. - V2
PS innervation to nasal cavities/paranasal sinuses?
- same pathway as lacrimal gland
- pre cell bodies: salivatory nucleus
- pre fibers: travel with cial n. (facial n. provides greater petrosal branch which exits temporal bone via hiatus for greater petrosal n., in middle cranial fossa it joins the deep petrosal n. to form the n. of the pterygoid canal, which travel in pterygoid canal to pterygopalatine fossa)
- post cell bodies: pterygopalatine ganglion
- post fibers: travel with branches of V2 to distribute to nasal cavities
sympathetic innervation to nasal cavities?
- pre cell bodies: T1-4
- post cell bodies: SCG
- post fibers: form internal carotid n –> deep petrosal n.
- deep and greater petrosal n. form nerve of the pterygoid canal.
- post fibers travel with branches of V2 to distribute to the nasal cavities and paranasal sinuses
lymphatic drainage of nasal cavities?
anterior portions drain along face to submandibular nodes
posterior portion drains along pharynx to retropharyngeal nodes
