Paranasal Sinuses Flashcards
Names of the paranasal sinuses?
Maxillary
Frontal
Sphenoid
Ethmoid
What is the function of the sinuses thought to be?
Contribute to humidifying the inspired air
Reduce weight of the skull
How are the sinuses formed?
During childhood, the nasal cavity erodes into the surrounding bone
Where, in general, are the openings into the nasal cavity found?
Roof and lateral walls of the cavity
What is the inner surface of the paranasal sinuses lined with?
Respiratory mucosa
What shape are the frontal sinuses?
Triangular
Where do the frontal sinuses drain into and via what?
Via the frontonasal duct which opens out at the hiatus semilunaris on the lateral wall
At what level do the sphenoid sinuses lie?
At the level of the sphenoid-ethmoidal recess
Where are the sphenoid sinuses located?
Superiorly
More posteriorly
Related superiorly and laterally to the cranial cavity
Where do the sphenoid sinuses drain into?
The roof of the nasal cavity
What is near the sphenoid sinuses which makes them clinically important?
Pituitary gland which can be surgically accessed through the sphenoid sinus and sphenoid bone
How many ethmoidal sinuses are there? Name them
Three
- anterior
- middle
- posterior
Where does each ethmoidal sinus drain into?
Anterior - hiatus semilunaris
Middle - ethmoid bulla
Posterior - superior meatus
Where are the maxillary sinuses located?
Laterally and slightly inferiorly to the nasal cavities
Where do the maxillary sinuses drain into?
At the hiatus semilunaris - underneath the frontal sinus opening
Pinkerton can easily spread between two of the sinuses. Which are they and why?
The frontal sinus and maxillary sinus
Fluid draining the frontal sinus can easily go into the maxillary sinus because the opening for the maxillary is just underneath the one for the frontal
What is sinusitis?
When infection of the upper respiratory tract spreads to the sinuses
Causes inflammation, pain and swelling of the mucosa
What is it called if more than one sinus is infected by sinusitis?
Pansinusitis
Why can inflammation of one of the sinuses present as toothache?
The maxillary nerve supplies both the maxillary sinus and maxillary teeth
Which of the sinuses is the largest?
The maxillary
How many paranasal sinuses are there?
Four paired
