H&N 7 Flashcards
what is a bleed from the nose called?
epistaxis
benign masses in nasal cavity?
polypi- vascular growth on surface of mucous membrane, originate from sinuses
FBs
rhioliths- stone formation
what comprises bony skeleton of external nose?
nasal bones
frontal processes of maxillae
nasal part of frontal bone (+ its nasal spine)
bony nasal septum
components of nasal septum?
anterior= cartilaginous central= perpendicular plate of ethmoid bone posterior= vomer bone
what might a direct blow on the nose result in, causing rhinorrhoea?
fracture of cribiform plate of ethmoid, causing tearing of overlying meninges and leakage of CSF into nasal cavity
how can nasal breathing be restored in a patient with a deformed or deviated nasal septum?
cartilaginous part can be removed (submucous resection-SMR) in part or whole
what forms roof of nasal cavity?
cribiform plate of ethmoid
what forms floor of nasal cavity?
palatal shelf of maxilla and palatine bone
where are the nasal turbinates located?
on lateral wall of nasal cavity
property of mucous membrane lining turbinates?
highly vascular in order to humidify inspired air
purpose of modification of lining epithelium of mucous membrane in sphenoethmoidal recess?
olfaction
where does frontal air sinus open into nasal cavity?
anteriorly in middle meatus
where does maxillary sinus open into nasal cavity?
posteriorly in middle meatus
what do the openings of the frontal and maxillary sinuses in the middle meatus lie at either end of?
a crescenteric groove= semilunar hiatus
where do anterior ethmoidal air cells open into nasal cavity?
middle meatus
ring of lymphoid tissue in nasopharynx?
adenoids= nasopharyngeal tonsils
where does profuse bleeding occur during nose bleeds?
Kiesselbach/Little’s area= an area in anterior part of nasal septum rich in capillaries where all arteries supplying septum anastomose
nerve supply to nasal mucosa is mainly via which nerve?
maxillary divison of trigeminal
why does the nasal mucosa become swollen and inflamed (rhinitis) in reaction to allergens and respiratory infections?
due to its vascularity and abundance of mucosal glands
where might infections of nasal cavity spread to?
anterior cranial fossa through the cribiform plate of ethmoid
paranasal sinuses via their openings into cavity
lacrimal apparatus and conjunctiva via opening of nasolacrimal duct
nasopharynx and retropharyngeal soft tissues
middle ear through Eustachian tube connecting tympanic cavity with nasopharynx
nerve supply to paranasal sinuses?
branches of opthalmic and maxillary divisions of trigeminal nerve
why might optic neuritis result from an infection of air cells of ethmoidal sinuses?
infections may break through medial wall of orbit, and affect dural sheath of optic nerve
nose functions?
olfaction- via olfactory nerve (CNI)
respiration- breathing
filter (remove dust) and humidify- vibrissae (course hairs) within vestibule, turbinates- on lateral wall of nasal cavity
drain and eliminate paranasal sinus and nasolacrimal duct secretions
vibrissae function?
moist so filter dust particles in inspired air
where does skin over cartilaginous part of nose extend?
into vestibule of the nose
how is the vestibule demarcated from the nasal cavity proper?
by the limen nasi
below this there is stratified squamous epithelium
above line is mucosal type
what comprises cartilaginous part of external nose skeleton?
2 lateral cartilages
2 alar cartilages= U-shaped, free and moveable, dilate or constrict nares when muscles acting on nose contract
1 septal cartilage
what is rhinitis?
swollen and inflamed nasal mucosa
causes of rhinits?
infective (viral)
allergies e.g. hayfever, occupation related
nasal polyps
dominant parasympathetic innervation, causing oversecretion
causes of epistaxis?
trauma
infection
hypertension
why might mild epistaxis occur from nose picking?
torn veins in nose vestibule
what is sinusitis?
inflammation of mucosal lining of sinuses
cause of sinusitis?
infection spreading from nasal cavities, viral infection with secondary bacterial infection- H influenzae and S pneumoniae
why might infection of ethmoidal air cells break through fragile medial wall of orbit?
nasal drainage blocked
- posterior ethmoidal drain into superior meatus
- anterior ethmoidal drain into middle meatus
clinical significance of some poster ethmoidal cells lying close to optic canal?
severe infection of ethmoidal cells may cause blindness as optic canal gives passage to optic nerve and opthalmic artery
how many days would a patient have to have sinusitis for it to be chronic?
> 90 days
how many days might a patient have acute sinusitis?
7 to 30
subacute sinusitis?
4 to 12 wks
how can infection of nasal cavity spread to anterior cranial fossa?
through cribiform plate of ethmoid bone
how can infection of nasal cavity spread to middle ear?
via eustachian tube between nasopharynx and tymanic cavity
how can infection of nasal cavity spread to paranasal sinuses?
via their openings into nasal cavity- meatuses and speno-ethmoidal recess
how can infection of nasal cavity spread to lacrimal apparatus and conjunctiva?
via nasolacrimal duct from inferior meatus
where are the maxillary ostia?
high on supero-medial walls of maxillary sinuses
symptom of patient with a cold or allergy involving both maxillary sinuses?
rolling from side to side during night in an attempt to keep sinuses drained as only upper sinus able to drain when lying on side.
why might a patient with inflammation of mucosa of their maxillary sinuses experience toothache in molar teeth?
as innervation of both mucous membrane of sinuses and maxillary teeth is via the superior alveolar nerves- branches of maxillary division of trigeminal
how can removal of maxillary tooth pose threat to maxillary sinus?
close proximity, so tooth extraction may fracture root, and if proper retrieval methods not used, a piece of root may be driven superiorly into maxillary sinus, so a fistula may form between oral cavity and sinus, and an infection may occur
how might a sinus containing excess fluid be determined?
transillumination of sinus
glow reduced if excess fluid, mass or thickened mucosa
what are paranasal sinuses?
paired, mucous membrane lined out-pocketings of nasal cavity, draining into nasal cavity
function of paranasal sinuses?
reduce weight of skull
may contribute to conditioning of inspired air
roof of maxillary sinus?
floor of orbit- maxilla, zygomatic and palatine bones
floor of maxillary sinus?
alveolar part of maxilla-roots of 1st 2 molars, so dental infection spread to maxillary sinus
superior alveolar nerve
what forms maxillary sinus posteriorly?
pterygopalatine and infratemporal fossae
what forms superior part of nasal septum?
perpendicular plate of ethmoid= descends from cribiform plate and is continued superior to plate as crista galli
complication of nasal fracture?
septa haematoma, can cause nasal septum necrosis, which can then result in saddle nose deformity
how does nasal cavity open into nasopharynx?
via choanae
lining of nasal vestibule?
skin
postero-inferior part of nasal septum formed by whar?
vomer
what forms medial wall of nasal cavity?
nasal septum
how is nasal septum formed?
develops as midline downgrowth and ultimately fuses with palatal shelves, which fuse in midline to form secondary palate
what forms lateral wall of nasal cavity?
conchae- curve inferomedially
cause turbulence, slowing air down, allowing mixing and time for warming and humidification to occur
what are middle and superior concha medial processes of?
ethmoid bone
what drains into nasal cavity?
middle ear
paranasal sinuses
lacrimal apparatus
5 sources of arterial blood supply to medial and lateral walls of nasal cavity?
anterior ethmoidal from opthalmic fron ICA
posterior ethmoidal
spenopalatine from maxillary from ECA
greater palatine from maxillary
septal branch of superior labial from facial from ECA
how do R and L frontal sinuses drain?
through a frontonasal duct, into ethmoidal infundibulum, which opens into the semilunar hiatus of the middle nasal meatus
what is the ethmoidal infundibulum?
a groove penetrating ethmoidal air cells, which drains frontal sinus
how are ethmoidal air cells joined together?
by cribiform plate
what is the crista galli?
a prominent point that project superiorly from cribiform plate of ethmoid bone and anchors the falx cerebri- a fold of dura mater
function of sphenopalatine foramen?
conducts sphenopalatine artery- branch of maxillary, nasopalatine nerve and superior nasal nerve= branches of maxillary nerve
function of cribiform plate
transmits olfactory nerve branches for sense of smell
joins ethmoidal air cells
function of foramen cecum?
allows passage of nasal veins to superior sagittal sinus
venous drainage of nasal cavity?
rich SM venous plexus drains into:
cavernous sinus
facial vein
pterygoid plexus in infratemporal fossa
blood supply to nasal septum?
kiesselbach’s (little’s area) plexus- at junction between limen nasi- between vestibular and mucosal linings, extensive capillary loops just below mucosal lining. Sign. artery anastomoses in this region between A and P ethmoidal, greater palatine, spheno palatine and septal branch of superior labial artery
which paranasal sinus is not present at birth?
frontal
external nose innervation?
trigeminal nerve: external nasal from opthalmic, and infraorbital from maxillary
function of lining respiratory epithelium with goblet cells of nasal cavity?
produce moist secretion which helps to humidify inhaled air
when does maxillary sinus enlarge?
from 8 yrs
when does sphenoid sinus enlarge?
after puberty
why does sinusitis tend to occur at adolescence and not in chood?
due to enlargement of PN sinuses occurring at this stage, whereas PN sinuses small during chood
what is frontal sinus related to?
orbit and A cranial fossa
what is sphenoid sinus related to?
pituitary fossa and middle cranial fossa
cavernous sinus and ICA
P cranial fossa and pons
roof of nasopharynx
relation of optic nerve to sphenoidal sinus?
nerve passes along lateral wall of sphenoid sinus
how do A ethmoidal cells drain?
into middle meatus via ethmoidal infundibulum
how do middle ethmoidal cells drains?
bulla- directly into middle meatus
what are nasal polpys?
sac like structures with lots of eosinophils, possibly linked to chronic rhinosinusitis
grow close to ostiomeatal complex of nasopharynx so block drainage route of PN sinuses
how might a patient with nasal polpys present?
snoring
obstructive sleep apnoea
what forms roof of nasal cavities posteriorly?
sphenoid
how are nasal and oral cavities separated inferiorly?
by hard palate- comprises palatine bone and maxilla bone
which artery would cause a posterior nosebleed?
sphenopalatine
describe the general sensory innervation of the nasal mucosa
Posteroinferior Nasal Mucosa:- maxillary Division of the Trigeminal Nerve -Nasopalatine Nerve
Anterosuperior Nasal Mucosa:- Opthalmic Division of the Trigeminal Nerve (CN V1)- Anterior and Posterior Ethmoidal Nerves from nasociliary nerve
before what age can the ethmoidal sinuses not be seen on an X-ray?
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