Nose, sinus + smell Flashcards
Function of the nose and sinuses
olfaction
ventilation
filtration of dust + pathogens
humidification of inspired air
reception + elimination of secretions from the nasal mucosa, paranasal sinuses and nasolacrimal ducts
Name the paranasal sinuses
4 pairs:
- frontal
- maxillary
- anterior ethmoid
- posterior ethmoid
- sphenoid
Why are the ethmoid sinuses different to the others?
honeycomb of cells compared to others which are air-filled areas
What is the uncinate process?
sickle shaped piece of bone descending from the ethmoid bone
forms medial wall of ethmoid infundibulum
What is the osteomeatal complex?
a functional concept - a space/area
final common pathway for drainage /ventilation of:
- frontal
- maxillary
- anterior ethmoid cells
Which sinuses are present at birth?
only maxillary and ethmoids
sphenoids at 7
frontals at 9
What genetic disorder can cause problems with sinus development?
cystic fibrosis
Describe the nasal cycle
unnoticeable alternating partial congestion and decongestion of the nasal cavities
one side breathes, one side filters and humidifies
normal to see one side of nose more congested than the other
What type of epithelium lines the nasal cavity?
ciliated pseudostratified columnar epithelium
How do we smell?
passage of odorised air
molecules attach to receptors in olfactory neuroepithelium
axons of receptor cells form fila
synapse in glomeruli of olfactory bulbs
2nd order neurones project to higher centres
What part of the brain controls sniffing?
cerebellum
Taste innervation
3 paired cranial nerves:
- facial - chorda tympani branch - anterior 2/3 of tongue
- glossopharyngeal - posterior 1/3 of tongue
- vagus - extraglossal taste buds
Where are taste buds located?
on papillae in the following locations:
- tongue
- palate
- oropharynx
- larynx (epiglottis)
- upper oesophagus
3 elements of flavour perception
smell
taste
touch
