A27 - Nasal Cavities and Para Nasal Sinuses Flashcards
where does the cartilage in the nose get most of its nutrients from?
the skin and mucosa surrounding it
what is the depression of the upper lip ?
philtrum
what bones make up the nasal cavity ?
- nasal
- ethmoid
- perpendicular plate to the ethmoid bone
- maxilla
- inferior nasal concha
what makes up the roof of the nasal cavity?
cribriform plate and crista galli of the ethmoid bone
what makes up the laterl wall of the nasal cavity ?
- superior and middle conchae which are part of the ethmoid bone.
- ethmoidal air cells
- orbital plate of ethmoid
what is the septum of the nose made up of ?
the perpendicular plate of the ethmoid bone joins with the vomer
what impact can le fort fracts have in the spread of infection?
cause the spread of infection from the nasal cavity and paranasal sinuses to the anterior cranial fossa
what mucosa makes up the opening of the nasal cavity?
keratinised stratified squamous epithelium
what mucosa makes up the majority of the nasal cavity?
respiratory epithelium
what mucosa makes up the roof of the nasal cavity?
olfactory mucosa
describe the olfactory nerve pathway.
- Receptor cells in the olfactory epithelium
- Pass up through the cribiform plate
- Synapse with olfactory bulb (ganglion)
- Then neurons pass along the olfactory tract
- To temporal lobe and olfactory areas
What part of the olfactory nerve passes through the cribriform plate of ethmoid bone in olfactory mucosa? It is the first neurone in the chain
receptor cells
What part of the of the olfactory nerve is a ganglion and has cell bodies of second neurones?
olfactory bulb
What part of the olfactory nerve ends in the temporal bone?
olfactory tract
what nerve supplies the nasal cavity with somatic sensory innervation ?
CN V (trigeminal)
what branch of CN V supplies the anterosuperior region of the nasal cavity?
CN Va
What region of the nasal cavity does CN Vb supply?
posterioinferior region
What nerve branches does CN Va supply the nasal cavity by?
Ethmoidal Branches of Nasociliary Nerve
What nerve branches does CN Vb supply the nasal cavity by?
Sphenopalatine and Greater Palatine Nerves
what is the branches of the external carotid artery that supply blood to the nose?
facial and maxillary artery
what is the branch of internal carotid artery that supply blood to the nose?
ophthalmic artery
what branch of ophthalmic artery supplies blood?
via anterior and posterior ethmoidal arteries
what branches of maxillary artery supply the nose of blood?
via sphenopalatine and greater palatine arteries
what branches of the facial artery supply blood to the nasal cavities ?
via lateral nasal branch of facial or septal brach of superior labial artery?
What is Keisselbach’s area?
an arterial anastomosis on the nasal septum that is a common side if epostaxis (nosebleed)
what is the role in the nasal conchea?
they increase the surface area covered by mucosa therefore increasing the surface area available to warm and humidify air
what are the meatus of the nasal cavity?
spaces under each of the conchae that act as draining sites for paranasal sinuses
What is the name for the open spaces within the bone of the nasal which is lined with thin respiratory epithelium?
paranasal sinuses
What are the four bilateral pairs of sinuses associated with the nasal cavity?
- frontal sinuses
- ethmoidal air cells
- maxillary sinuses
- sphenoid sinuses
which nasal concha is made up of a bone on its own?
inferior
where does the frontal sinuses drain into?
middle meatus
where do ethmoidal air cells drain into?
superior and middle meatuses
where do sphenoidal sinus drain into?
sphenoethmoidal recess
where does the maxillary sinus drain into?
middle meatus
where do tears drain into?
wash over eye and drain into the nasolacrimal duct > inferior meatus
What are the right and left nasal cavities separated by?
Nasal septum formed from the perpendicular plate of the ethmoid bone and the vomer (posteriorly) and the septal cartilages (hyaline) anteriorly
What are the functions of the nasal cavity?
- convey respiratory gases between the atmosphere and nasopharynx
- warm
- humidify
- remove particulate matter
- special sense of smell
What lines the paranasal sinuses?
Mucus Secreting Respiratory Mucosa
How does mucous drain into nasal cavities?
Via ostia in the lateral walls of the nasal cavities
what is sinusitis?
inflammation of the mucosa in 1 or more of the paranasal sinuses
What can cause swelling of the mucosa which reduces the diameter of the Ostia?
viral URTI
what are the causes of sinusitis ?
- infection
- allergy
- autoimmune issues
what sensory nerves supply pain in patients with sinusitis ?
CN Va and Vb
What sinus is predisposed to infection as the ostium of this sinus is located superior in relation to its cavity? Cilia must work against gravity
maxillary sinuses
what is an Oro-antral fistula?
communication between the maxillary sinus and the tooth socket
How can tooth infection lead to sinus infections?
If the roots pierce upwards into the maxillary sinus
What happens if there is improper closure of the oro-antral fistula?
Sinusitis pain can be referred to the teeth and present as “toothache”
