Nasal Sensation Screencast Flashcards
What are the three distinct parts of the nasal cavity?
Nasal vestibule, respiratory epithelium, olfactory epithelium
What cells line the nasal vestibule?
Stratified squamous epithelium (keratinised to non-keratinised)
What does the nasal vestibule represent?
The initial transition from the skin of the face to specialised mucosa of the nasal cavity
Where does the respiratory epithelium cover in the nasal cavity?
Middle and inferior cochlea and their associated meatuses
Where is the olfactory epithelium located in the nasal cavity?
Located superiorly = covers superior cochlea and spheno-ethmoidal recess
What is the function of the nasal conchae in olfaction?
Create turbulence which holds air in the nasal cavity for longer to allow air to reach olfactory sensors on the roof
What do olfactory receptors form?
Olfactory epithelium
How can olfactory nerve receptor cells be described as bipolar?
Have their cell bodies within the epithelium, have dendrites which pick up odorants, and axons which convey these through the cribriform plate
Which bone is the cribriform plate associated with?
The ethmoid bone
Where is the olfactory area split between?
On the lateral wall of the nasal cavity and the nasal septum
What nerve provides special sensory olfaction input and output?
Cranial nerve I (olfactory nerve)
What is the olfactory pathway?
Receptor cells in olfactory epithelium Pass up through cribriform plate Synapse with olfactory bulb (ganglia) Neurons pass along the olfactory tract Go to temporal lobe and olfactory areas
What provides general somatic sensory innervation to the anterosuperior aspect of the nasal cavity?
Ophthalmic division of the trigeminal nerve (CN V1)
What provides general somatic sensory innervation to the postero-inferior aspect of the nasal cavity?
Maxillary division of the trigeminal nerve (CN V2)
What nerve represents the ophthalmic division of the trigeminal nerve in supplying the nasal cavity?
Anterior ethmoid nerve (CN V1) = passes through anterior ethmoidal foramina closely related to the cribriform plate
What provides general somatic sensation to the tip of the nose and the external bridge of the nose?
CN V1 = anterior ethmoid nerve
What nerve represents the maxillary division of the trigeminal nerve in supplying the nasal cavity?
Nasopalatine nerve (CN V2) = passes through sphenopalatine foramen and courses inferiorly
What features of the nasal cavity are covered by the nasopalatine nerve (CN V2)?
Middle and inferior conchae, and their associated meatuses
Where does the nasopalatine nerve (CN V2) course on the septum?
Courses diagonally towards the incisive foramen and descends through this foramen
What supplies the hard palate with general somatic sensation?
CN V2 = nasopalatine nerve
Where does the nasopalatine nerve (CN V2) send axons towards once it passes through the incisive canal?
Sends axons towards the hard palate
What is the ophthalmic division of the trigeminal nerve (CN V1) closely related to?
The orbits of the eyes = send axons through the orbit
Where do axons from the ophthalmic division of the trigeminal nerve (CN V1) go once they have left the orbit?
Sent through the superior orbital fissure before having its cell bodies in the trigeminal ganglion
Where is the trigeminal ganglion located?
On the lateral aspect of the cavernous sinuses in the middle cranial fossa
Where does the trigeminal ganglion send its axons to?
Into the posterior cranial fossa and into the pons
Where does the maxillary division of the trigeminal nerve (CN V2) send its axons to?
Sends axons through the foramen rotundum and into the trigeminal ganglion
