8. Nose, nasal cavity and paranasal sinuses (lecture) Flashcards
what are the functions of the nose and nasal cavity?
- sense of SMELL (olfaction)
- provides ROUTE for inspired air
- FILTERs inspired air
- moistens and warms inspired air
- RESONATing chamber for speech
how does the nose filter inspired air?
removing particles by trapping in nasal hair or mucous
what is behind the nasal cavity?
nasopharynx
what is an anatomical connection with the middle ear?
eustachian tube
what is the floor of the nasal cavity?
roof of palate (hard palate in front, soft palate behind)
what is the external nose made of?
cartilage
what forms the hard palate?
maxilla bone
what is the vestibule?
entrance to nasal cavity (hole of nose)
what is the vestibule lined with?
skin, has some sebaceous glands
hair cells
what is the external nose made up of?
cartilage and bone
what is the function of the cartilaginous element of the external nose?
gives rise to shape of nsoe
where is the base of the nose?
root
where the glasses rest - the bony part
where does the bony part of the nose end?
at the bridge
where do you apply pressure during nose bleeds?
to the part between bony and cartilaginous nose
just in front of bony part of nose
what is the tip of the nose also known as?
apex
what are the nostrils of the nose also known as?
nares
which bone forms the bony part of the nose?
nasal bone
and frontal process of maxilla
which part of the nose is most commonly fractured?
nasal bone
often lots of swelling
can’t reset bone until swelling has gone down (5-7 days later)
what is the significant of prominence of nasal bones?
susceptible to fracture in facial injuries
what should you check for during facial injuries?
other damage within the facial structure
other structures aside from nose can also be damaged as patient must have sustained considerable force to face
lateral walls of the nasal cavity?
maxilla bone
medial wall of nasal cavity?
nasal septum
floor of nasal cavity?
roof of oral cavity:
hard and soft palate
what makes up the hard palate?
floor of nasal cavity / roof of oral cavity:
maxilla + 2 x palatine bones
roof of nasal cavity?
nasal cartilages and several bones:
nasal and frontal bones, the cribriform plate of the ethmoid, the body of the sphenoid
where is the nasal cavity situated?
behind nostrils
what forms the nasal septum?
bones:
- perpendicular plate of ethmoid bone
- vomer bone
cartilage: septal cartilage
where does cartilaginous part of septum take blood supply from?
overlying perichondrium
what can trauma to nose lead to?
buckling of septum (crumble under force) and shearing of blood vessels
what happens in septal haematoma?
blood accumulates between perichondrium and cartilage
what should you always examine for in patients presenting with nasal injury?
septal haematoma
how should you treat septal haematoma?
stick a syringe in, aspirate the blood out of the space, package it to ensure that nasal cartilage gets blood supply back and blood doesn’t re-accumulate
what can untreated septal haematoma lead to?
avascular necrosis of CARTILAGINOUS septum
how does avascular necrosis of cartilaginous septum present?
saddling of nasal dorsum
saddle-nose deformity
what else can arise from septal haematoma aside from avascular necrosis of cartilage?
can develop infection in the collecting haematoma
(septal abscess formation further increases likelihood of avascular necrosis of septum)
haematoma = breeding ground for infection –> septal abscess
what forms the lateral wall of the nasal cavity?
bony conchae (projections) of the maxilla bone superior, middle and inferior
what is the purpose of S,M,I conchae?
slows airflow
increases surface area over which air passes
(to warm and humidify inspired air)
what lies inferior to the conchae?
meatuses (spheno-ethmoidal recess)
some sinuses drain into middle meatus
what drains into inferior meatus?
ONLY nasolacrimal duct
