Thorax- nose Flashcards
What is the function of the nose and nasal cavities?
olfaction (smelling)
respiration
filtration of dust
humidification of inspired air
reception and elimination of secretions from nasal mucosa, paranasal sinuses and nasolacrimal ducts
What does the bony part of the nose consist of
nasal bones
frontla process of maxillae
nasal part of frontal bone and nasal spine
bony part of nasal septum
What does the cartilaginous part of the nose consist of
two lateral cartilages
two alar cartilages (U shaped, can move around)
septal cartilage
where do nasal cavities open to?
what lines it?
- Entered through nares open posteriorly to nasopharynx through choanae
- Mucosa lines nasal cavities except the vestibule of nose (skin)
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boundaries of the nasal cavity
- Roof: curved and narrow except at posterior end
- Floor- hard palate
- Medial wall: nasal septum; perpendicular plate of ethmoid, vomer, septal cartilage and nasal crests of maxillary and palatine bones
- Lateral wall: uneven- nasal conchae and meatus
what is the mucosa of nasal cavities continuous with?
all chambers communicating with nasal cavities: nasopharynx (posteriorly), paranasal sinuses (superiorly and laterally), the lacrimal sac and conjunctiva superiorly
what is unique about the olfactory area?
specialised mucosa with peripheral organ of smell, sniffing draws air
- Receptor neurones in olfactory epithelium- forms nerve bundles passing through cribriform plate of ethmoid bone and enters olfactory bulb
what are nasal conchae
curves projecting out of the lateral wall
- inferior, middle and superior
creates meatus for the air to flow
why are meatus’ important in respiration
increases surface area- increases amount of air inspired and come in contact with cavity walls
Slows down air flow and makes it turbulent, humidified and cleaned.
where is the spheno-ethmoidal recess
in superior concha
receives opening of sphenoidal sinus
where is the ethmoidal infundibulum
middle meatus communicates with frontal sinus
where is the Semi-lunar hiatus
openings of frontal, maxillary and anterior ethmoidal sinuses
where does the nasolacrimal duct drain into
inferior meatus (tears in eye)
what is the ethmoidal bulla
bulge in lateral wall formed by middle ethmoidal sinus
what are paranasal sinuses and what do they do
what are they lined with
air filled extensions of respiratory part of nasal cavity
humidifies air, makes the skull weigh lighter
respiratory mucosa
Frontal sinus:
triangular shaped
- Frontalnasal duct-> ethmoidal infundibulum -> semilunaris hiatus -> middle meatus
- CN V1: supra-orbital nerves