Flashcards in Nasal Cavity and Paranasal Sinuses Deck (27)
What are the nasal choanae?
Entrance to the nasopharynx at the posterior wall of the nasal cavity
What forms the roof of the oral cavity?
Hard and soft palates
What is the function of the hard palate?
Separates nasal and oral cavities
What are the borders of the nasal cavity?
Roof: Cribriform plate of the ethmoid bone
Lateral walls: concha, palatine bones and maxilla
Medial walls: nasal septum
Inferior wall: hard palate
Anterior wall: nares (nostrils)
Posterior wall: nasal choanae
What is the function of the nasal concha?
Warm and humidify air by creating turbulent air flow
Trap particulate matter
Increase the surface area of the nasal cavity
What are the meatus?
Spaces underneath nasal concha
What are nasal polyps? What causes them and what are the potential complications?
Usually painless, non-cancerous, swollen masses
Can be caused by chronic inflammation
Can cause blockage of the drainage of paranasal sinuses and problems with voice resonation.
Can block the passage of air through the nasal cavity
What are the 3 regions of the nasal cavity?
What type of epithelium covers them and what is its function?
Olfactory region: respiratory epithelium (pseudo-stratified ciliated columnar) with olfactory sensory nerve endings to provide sense of smell.
Nasal vestibule: stratified squamous epithelium: helps resist abrasion. Hair bearing: traps particulate matter.
Respiratory region: Pseudo-stratified ciliated columnar epithelium with goblet cells that product mucous. Warms and humidifies inspired air.
What bones make up the nasal cavity?
Cartilage forms anterior portion
What is the nasal septum composed of?
Anterior portion= cartilage
Posterior portion= vomer
What is the blood supply to the nasal cavity?
Internal carotid supplies superior portion
External carotid supplies inferior portion
Branches of these anastomose on the nasal septum to form the Kiesselbach plexus (Little area)
Describe the innervation of the nasal cavity
What can be a consequence of a fracture of the cribriform plate?
Loss of sense of smell due to shearing of projections of the olfactory nerve.
Leaking of CSF into the nasal cavity
What are the 4 paranasal air sinuses?
Where does the frontal sinus drain into?
Drains inferiorly via frontonasal duct into the hiatus semilunaris
Where is the hiatus semilunaris?
In the middle meatus
Where do the sphenoid sinuses drain into?
Drain into the sphenoethmoidal recess
Where do the ethmoid sinuses drain into?
Anterior: hiatus semilunaris
Middle: ethmoid bulla
Posterior: superior meatus
Where do the maxillary sinuses drain into?
Superiorly into the hiatus semilunaris underneath the opening of the frontal sinus.
What is the clinical relevance of the maxillary sinus drainage route?
Drainage route potential route for infection spread.
Superior drainage can lead to infection.
Inflamted mucosa can swell, further impeding drainage.
What is the sensory innervation of the paranasal sinuses?
All innervated by Va of the trigeminal nerve
EXCEPT maxillary sinuses: Vb of the trigeminal.
Where does the nasolacrimal duct drain into?
Where can pain from maxillary sinusitis refer to?
What structure can be accessed surgically through the sphenoid sinus?
What are the close anatomical relations of the ethmoid sinuses?
What is the clinical relevance of this?
Infection spread from sinuses to orbit.
Plate of bone separating the two is thin and vulnerable to fracture.
What can cause blockage of the nasolacrimal duct?