8. Nose, nasal cavity and paranasal sinuses (DR) Flashcards
what is the function of the nose?
- olfaction (smell)
- upper part of respiratory tract
- drains and eliminates
as the nose is part of the upper part of respiratory tract, what function does it carry out?
filters and humidify inspired air
what does the nose drain and eliminate?
paranasal sinuses and nasolacrimal duct secretions
how can the nose be divided?
into external nose and nasal cavity
what is contained within the external nose?
cartilaginous part
bony part
what is contained within the nasal cavity?
medial wall
roof
lateral wall
floor
what is the nasal cavity lined with?
mucous membrane (secretory mucus to trap dirt particles)
how can the nasal cavity be divided?
into olfactory portion and respiratory portion
nerve supply to the nasal cavity?
CN I (olfactory) CN V (ophthalmic (V1) and maxillary (V2) division)
what is the function of CN I (olfactory) in the innervation of the nasal cavity?
special sense of smell
what is the function of CN V (ophthalmic and maxillary division) of the nasal cavity?
general sensation
V1 (respiratory), V2 (olfactory)
how can V1 and V2 division of general sensation of the nose be divided?
by drawing an imaginary vertical tilted line up the nose from the nasal cavity opening
what are the paranasal sinuses?
sphenoid ethmoid frontal nasal (hollow, air-filled chambers in the bones around the nose)
function of paranasal sinuses?
make the skull lighter
mucous from the sinuses drain into the nasal cavity
what is the nasal cavity?
hollow space behind the nose that air flows through
what does mucous membrane line?
thin tissue lining the nose, sinuses, and throat
what is the function of the mucous membrane?
warms, moistens the air breathed in
also makes the sticky mucus that helps clean the air of dusts and other small particles
what is the nasal septum?
medial wall of nasal cavity
‘wall’ of cartilage and bone
divides inside of nose into 2 chambers
what are the turbinates of the nose?
either side of the nose
curved, bony ridges lined with mucous membrane
what is the function of turbinates of the nose?
increase surface area
warm and moisten air breathed in
why is maxillary sinus the most commonly affected sinus in sinusitis?
due to close anatomic relation with frontal sinus, anterior ethmoidal sinus and the maxillary teeth - easy spread of infection
drainage of orifice near roof of sinus - doesn’t drain well
where does maxillary sinus drain into?
middle meatus of the nose
