Nasal cavities and paranasal sinuses Flashcards
what make up the external nose?
- root
- dorsum
- apex(tip)
- ala
- nares(nostril)
- septum
- philtrum (upper lip)
what makes the roof of the ethmoid bone?
cribriform plate and crista galli (+anterior cranial fossa)
what makes up lateral wall of the ethmoid bone?
superior and middle conchae, ethmoidal air cells, orbital plate of ethmoid (+inferior conchae)
what makes up the septum?
perpendicular plate of ethmoid + vomer
what is the problem with le fort II and III if they distrust the cribifrom plate of the ethmoid bone?
danger of infection spreading from the nasal cavity & paranasal sinuses into the anterior cranial fossa
what makes up the medial wall of the nasal cavity ?
- vomer
- septal (hyaline cartilage)
- perpendicular plate of ethmoid
what makes up the lateral wall of the nasal cavity?
- frontal bone
- nasal bone
- anterior cranial fossa
- palatine bone
- maxilla
what are the 3 types of mucosa of the nasal cavities?
1) keratinised stratified squamous epithelium
2) respiratory epithelium
3) olfactory mucosa
what modality is the olfactory Nerve?
special sensory
Describe receptor cells
pass through cribriform plate of ethmoid bone
in olfactory mucosa
1st neurones in chain
Describe the olfactory bulb
ganglion
cell bodies of 2nd neurones
where does the olfactory tract end?
Ends in temporal lobe
where is the olfactory bulb found?
lateral and medial side of nose
what nerves supplies the lateral wall and the septum of the nasal cavity?
- ophthalmic (CN V1)
- Maxillary (CN V2)
what supplies the anterosuperiorly area of the nasal cavity?
-Ophthalmic (CN V1)
what supplies the posterioinferiorly area of the nasal cavity?
maxillary (CN V2)
what branch of V1 supplies the lateral wall and septum of the nasal cavity?
anterior and posterior ethmoidal branches of nasocillary nerve
what is the blood supply to the nasal cavities?
- facial from external carotid (via lateral nasal branch of facial or septal branch of superior labial artery)
- maxillary from external carotid (via sphenopalatine and greater palatine arteries)
- ophthalmic artery from internal carotid (via anterior and posterior ethmoidal arteries)
what makes up kiesselbachs (littles) area?
-an arterial anastomosis on the nasal septum of
what is an epistaxis?
nosebleeds
what two conchae are part of the ethmoid bone?
superior and middle
what conchae is its own bone?
inferior
what meatuses are found in the nasal cavity?
- sphenoethmoidal recess found between ethmoid and sphenoid bone
- superior meatus found under superior concha
- middle meatus found under middle concha
- inferior meatus found under inferior concha
what are the functions of the nasal cavities?
- Filters air of particulate material (vibrissae = small hairs)
- Humidifies air (glands)
- Warms inspired air in the nasal passage (blood)
- Sense of smell as air passes over the olfactory epithelium
what are the 4 paranasal sinuses?
- 1 frontal bone (x2 frontal sinuses and separated by bony septum)
- 2 maxillae (x2 maxillary sinuses)
- 1 ethmoid bone (x2 sets ethmoidal air cells)
- 1 sphenoid bone (x1 or x2 sphenoidal sinuses)
what lines the paranasal sinuses?
mucous-secreting respiratory mucosa
what is the function of mucous?
mucous drains into nasal cavities via ostia in the lateral walls of the nasal cavities
where does the frontal sinus drain into?
middle meatus
where does ethmoidal cells drain?
superior and middle meatuses
where does the sphenoidal sinus drains into?
sphenoethmoidal recess
where does lacrimal fluid drain?
anterior aspect of inferior meatus via the nasolacrimal duct
what are the causes of inflammation of the mucosa of paranasal sinuses?
- infection
- allergy
- autoimmune issues
