The Nasal Cavity 1 Flashcards
what is the nose?
an olfactory (smell) and respiratory organ
what does the nose consist of?
nasal skeleton, which houses the nasal cavity
what are the functions of the nasal cavity?
- Warms and humidifies the inspired air
- Removes and traps pathogens and particulate matter from the inspired air
- Sense of smell
- Drains and clears the paranasal sinuses and lacrimal ducts
where is the nasal cavity?
the most superior part of the respiratory tract
where does the nasal cavity extend?
from the vestibule (nostril) of the nose to the nasopharynx
what are the divisions of the nasal cavity?
Vestibule
Respiratory region
Olfactory region – located at the apex of the nasal cavity. It is lined by olfactory cells with olfactory receptors.
what is the vestibule?
the area surrounding the anterior external opening to the nasal cavity
what is the respiratory region lined by??
ciliated psudeostratified epithelium, interspersed with mucus-secreting goblet cells
where is the olfactory region located?
at the apex of the nasal cavity
what is the olfactory region lined by?
olfactory cells with olfactory receptors
what are the nasal conchae?
Projecting out of the lateral walls of the nasal cavity are curved shelves of bone (conchae / turbinates)
how many conchae are there?
three conchae – inferior, middle and superior
where do the nasal conchae project into?
the nasal cavity, creating four pathways for the air to flow (meatus)
where is the inferior meatus found?
between the inferior concha and floor of the nasal cavity
where is the Spheno-ethmoidal recess found?
Lies superiorly and posteriorly to the superior concha
what is the function of the conchae?
to increase the surface area of the nasal cavity – this increases the amount of inspired air that can come into contact with the cavity walls (where blood vessels are to warm inspired air)
another function of conchae aside from increase SA?
They also disrupt the fast, laminar flow of the air, making it slow and turbulent. The air spends longer in the nasal cavity, so that it can be humidified
what is one of the functions of the nose?
to drain a variety of structures
what is required in order for structures to drain into the nose?
there are many openings into the nasal cavity, by which drainage occurs
where do the paranasal sinuses drain into?
the nasal cavity
which structures open into the middle meatus?
The frontal, maxillary and anterior ethmoidal sinuses
what is the middle meatus opening marked by?
the semilunar hiatus (a crescent-shaped groove on the lateral walls of the nasal cavity)
what does the middle ethmoidal sinus emoty into?
a structure called the ethmoidal bulla
what is the ethmoidal bulla?
a bulge in the lateral wall formed by the middle ethmoidal sinus itself
where does the posterior ethmoidal sinus open out at?
the level of the superior meatus
where does the sphenoid sinus empty into?
drains onto the posterior roof
The only structure not to empty out onto the lateral walls of the nasal cavity
in addition to the paranasal sinuses, which other structures open into the nasal cavity?
- nasolacrimal duct
2. auditory (or eustachian) tube
function of the nasolacrimal duct?
drain tears from the eye
where does the nasolacrimal duct open into?
the inferior meatus
where does the eustachian tube open into?
the nasopharynx at the level of the inferior meatus
function of the auditory (eustachian) tube?
allows the middle ear to equalise with the atmospheric air pressure
what does the auditory tube connect?
middle ear and upper respiratory tract
what does the auditory tube provide a path for?
infection to spread from upper respiratory tract to ear
what does infection of the auditory tube cause? resulting in?
swelling of the mucous lining, and the tube becomes blocked
results in diminished hearing
