Head and Neck, Session 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