When does aeration of the frontal sinus begin?
Age 4-5 years, continues into the late teens
What percentage of the population has a unilateral frontal sinus?
At what age can the maxillary sinuses be visualized on CT?
Age 4-5 months
The is fully formed by the 5th week gestation and goes on to develop into the floor of the nose/palate.
What are the nasal anatomic subunits?
- nasal dorsum
- nasal sidewalls
- nasal tip
- alar lobules
- depressions of the supra-alar facets
Which muscles elevate the nose?
- Levator labii superioris alaeque nasi
- Anomalous nasi muscles
Which muscles depress the nose?
- Alar nasalis
- Depressor septi nasi muscles
What are the other muscles of the nose (the compressor and dilators)?
- Transverse nasalis
- Compressor narium minor
- Dilator naris anterior muscles
What is the narrowest portion of the nasal cavity?
What is the nasal valve?
The angle between the caudal quadrangular cartilage and the distal upper lateral cartilages
What is the only septal component that is paired?
The vomer, which may be bilaminar owing to its dual embryonic origin
What makes up the superior portion of the bony nasal septum?
Perpendicular plate of the ethmoid
What are the major tip support mechanisms?
- Contour, size, and strength of the lateral crura
- Attachment of the medial crural footplate to the caudal septum
- Attachment of the caudal edge of the upper lateral cartilages to the cephalic border of the alar cartilages
What are the minor tip support mechanisms?
- Nasal tip ligamentous aponeurosis
- Cartilaginous septum
- Nasal spine
- Strength and resilience of the medial crura
- Thickness of tip skin and subcutaneous tissue
- Supportive strength of the alar sidewalls
What are the major anatomic features that determine tip projection?
- Thickness and character of tip skin
- Shape and strength of alar cartilages
- Length of infratip lobule and columella
- Anatomy of the quadrangular cartilage (esp the anterior septal angle)
- Size of the nasal spine and premaxilla
What type of epithelium lines the nasal cavity?
Ciliated pseudostratified epithelium
What neuropeptide is thought to be a mediator of pain in the nose and paranasal sinuses?
What are odorous substances made of?
Either gases or volatile liquids
How is sensory epithelium of the olfactory system different from the surrounding respiratory epithelium?
Both have cilia, but the cilia of the olfactory epithelium do not beat synchronously
What are Bowman's glands?
They secrete mucus and yellow pigment in the olfactory epithelium. The odorant must dissolve in this layer of mucus to reach the sensory receptors.
How are the receptor cells in the olfactory system different from those of the ear, eye, and tongue?
They are bipolar nerve cells (others are specialized epithelial cells)
Unlike the taste pathway to the cerebral cortex, the olfactory pathway does not relay in the . The olfactory nerve terminates in the and sends axons via the olfactory tract to the piriform cortex, the periamygdaloid area, and the .
- Olfactory bulb
- Olfactory tubercle
What is the most common cause of taste loss?
What is dysosmia?
Perception of an unpleasant odor
What is phantosmia?
Perception of an odor in the absence of a stimulus
What is parosmia?
Distorted perception of an odor
Where does the nasolacrimal duct lie in relation to the osmium of the maxillary sinus?
The majority of posterior ethmoid cells empty into which meatus?
What percent of the population has a supreme nasal concha?
What are the 5 basal or ground lamella of the paranasal sinuses?
- Uncinate process
- Bulla ethmoidalis
- Basal lamella of the middle turbinate
- Lamella of the superior turbinate
- Lamella of the supreme turbinate (if present)
What structure separates the anterior and posterior ethmoid complexes?
Basal lamella of the middle turbinate
Where does the natural ostium of the maxillary sinus empty?
What is the most posterior part of the middle turbinate attached to?
Crista ethmoidalis of the perpendicular process of the palatine bone
Where does the anterior portion of the middle turbinate most often attach superiorly?
Laterally onto the lamina papyracea (may also attach to the skull base)
What is an agger nasi cell?
- Pneumatized area of the lateral nasal wall immediately anterior and superior to the insertion of the middle turbinate.
- The most anterior ethmoid air cell
What problem can an enlarged agger nasi cell cause?
Narrowing of the frontal recess
What is the term for a persistent, nonpneumatized second basal lamella?
What is the term for a pneumatized second basal lamella?
What is the most posterior aspect of the anterior ethmoids?
When may the suprabullar recess extend into the retrobullar recess?
If the posterior wall of the bulla lamella is not in contact with the basal lamella of the middle turbinate
What is another name for the retrobullar recess?
What does the retrobullar recess drain into?
hiatus semilunaris superior
What recess does the suprabullar recess open into?
Frontal recess; anteriorly is is separated from the recess by the bulla lamella
What are the borders of the ethmoid infundibulum?
- Medially, the uncinate process
- Laterally, the lamina papyracea and frontal process of the maxilla
- Posteriorly, the ethmoid bulla
Into what does the ethmoid infundibulum drain posteriorly?
Hiatus semilunaris inferior
Where does the maxillary sinus ostium lie in relation to the ethmoid infundibulum?
At the floor and lateral aspect of the infundibulum, between its middle and posterior 1/3
Where is the anterior ethmoid artery found intranasally?
Anterior to the vertical portion of the basal lamella, immediately below the skull base, and posterior to the frontal recess
What is the distance from the posterior ethmoid artery to the optic foramen?
Which table of the frontal sinus is thinner?
Where is the natural ostium of the fontal sinus?
The posteromedial aspect of the sinus floor
What is the frontal recess?
The drainage pathway from the frontal sinus to the nasal cavity
What forms the anterior boundary of the frontal recess?
The posterior wall of the agger nasi and frontoethmoid cells, if present
What structures form the posterior boundary of the frontal recess?
The ethmoid bullae, suprabullar space, anterior skull base, and anterior ethmoid artery; frontal bulla cell