Nasal cavity and paranasal air sinuses Flashcards
Which structure connects the nasal cavity to the nasopharynx?
Nasal choanae
What pathology could affect the nasal choanae and in which age group is it most common?
Choanal atresia – a congenital blockage of the choanae, which can be unilateral or bilateral, leading to difficulty breathing
Particularly in infants
What are the nasal concha?
Bony shelves that project inferomedially from the lateral wall on both sides
What is the space under each concha called?
Meatus
How do the concha affect the temperature of air that is breathed in through the nasal cavity?
As air passes over the highly vascular mucosal tissue of the conchae, it is warmed to near body temperature
What kind of air flow do the shape of the concha produce and why is this helpful?
Turbulent air flow, which helps slow down the movement of air for temperature regulation and filtration of particles so they do not reach the lungs
How does the nasal cavity affect sound?
It produces resonance – the amplification of sound frequencies as they pass through the nasal passages
What are the 3 regions that the nasal cavity can be divided into based on the mucosa that lines it?
Nasal vestibule region
Respiratory region
Olfactory region
What epithelium lines the respiratory region of the nasal cavity?
Pseudostratified ciliated columnar epithelium
What are the 4 components of the nasal septum?
Septal cartilage
Ethmoid bone
Vomer
Hard palate
The superior and middle concha are part of which bone?
Ethmoid bone
Which 5 bones comprise the lateral wall of the nasal cavity?
Superior and middle concha (ethmoid bone)
Inferior concha
Nasal bone
Palatine
Maxilla
Describe the blood supply to the nasal cavity.
Anterior and posterior ethmoidal arteries branch off from the internal carotid artery
Sphenopalatine artery branches off from the maxillary artery which branches off from the external carotid artery
In which area do the arteries from both the internal and external carotid systems anastomose in the nasal cavity and what is the name given to this area?
The anterior nasal septum
Kiesselbach’s Plexus (Little’s Area)
Which 2 nerves innervate the nasal cavity?
Olfactory nerve
Trigeminal nerve Va (ophthalmic division) & Vb (maxillary division)
Considering referred pain, where could a pathology in the front of the nasal cavity refer pain to?
Forehead
Considering referred pain, where could a pathology in the middle and back of the nasal cavity refer pain to?
Maxillary teeth
The fibres of the olfactory nerve pass through what to enter the nasal cavity?
Cribriform plate
What could a fracture of the cribriform plate lead to?
A cerebral spinal fluid leak from the nose
The nasolacrimal duct drains into where?
Inferior meatus
What is dacryocystitis?
Inflammation of the lacrimal sac
What is dacrostenosis?
Obstruction of the nasolacrimal duct
What are the 4 pairs of sinuses?
Frontal
Ethmoid
Maxillary
Sphenoid
Describe the innervation of the sinuses.
Frontal - Va
Sphenoid - Va
Ethmoid - Va
Maxillary - Vb
Where do the sphenoid sinuses drain into?
Sphenoethmoidal recess
Where do the frontal, maxillary, and majority of the ethmoid sinuses drain into?
Middle meatus
The maxillary sinus drains into the middle meatus via what?
Semilunar hiatus
Which sinus can be used to access the pituitary gland?
Sphenoid sinus
What separates the ethmoid sinuses from the orbit?
Lamina papyracea
Due to the thinness of the lamina papyracea, ethmoid sinus infections can lead to what pathology?
Periorbital cellulitis
