Nasal cavity
- Created by: saoirselb
- Created on: 06-11-19 11:11
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- Nasal cavity
- Divisions
- Vestibule
- area surrounding anterior external opening to nasal cavity
- Respiratory region
- lined by ciliated pseudostratified epithelium, interspersed with mucus secreting goblet cells
- Olfactory region
- located at apex of nasal cavity
- lined by olfactory cells with olfactory receptors
- Vestibule
- Nasal conchae
- curved shelves of bone projecting out the lateral walls of the nasal cavity
- Create 4 meatuses - pathways for the air to flow
- Inferior meatus: between inferior concha and floor of nasal cavity
- Middle meatus: between inferior and middle concha
- Superior meatus: between middle and superior concha
- Sphemo-ethmodial recess: superiorly and posteriorly to the superior meatus
- 3 conchae: inferior, middle and superior
- Function
- Increases surface area of nasal cavity
- increases amount of inspired air that can come into contact with cavity walls
- Disrupts fast, laminar flow of air
- Makes air flow slow and turbulent - air spends longer in cavity so it can be humidified
- Increases surface area of nasal cavity
- Openings into cavity
- Paranasal sinuses
- Drain into the nasal cavity
- Frontal, maxillary and ethmoidal sinuses open into the middle meatus
- Location marked by semi-lunar hiatus on walls of nasal cavity
- Middle ethmoidal sinuses empty into ethmoidal bulla
- Ethmoidal bulla: bulge in lateral wall formed by middle ethmoidal sinus
- Sphenoid sinus doesn't empty onto lateral walls - drains onto posterior roof
- Nasolacrimal duct
- Drains tears from eyes, opens into inferior meatus
- Auditory (Eustachian) tube
- Opens into nasopharynx at level of the inferior meatus
- Allows middle ear to equalise with atmospheric pressure (popping ears after flying)
- Paranasal sinuses
- Gateways to the nasal cavity
- Cribriform plate
- Part of ethmoid bone
- Forms portion of the roof of the nasal cavity
- contains small perforations to allow fibres of olfactory nerve to enter and exit
- Sphenopalatine foramen
- At level of superior meatus
- Allows communicaton between the nasal cavity and pterygopalatine fossa
- Sphenopalatine artery, nasopalatine and superior nasal nerves pass through
- Incisive canal
- pathway between nasal cavity and incisive fossa of oral cavity
- transmits the nasopalatine nerve and greater palatine artery
- Cribriform plate
- Innervation
- Special sensory innervation
- refers to ability to smell
- Carried out by olfactory nerves
- Olfactory bulb (part of brain) lies on top of cribiform plate above nasal cavity
- Branches of the olfactory nerve run through the cribiform plate to provide special sensory innervation to nose
- General sensory innervation
- Innervation to septum and lateral walls
- Delivered by nasopalatine nerve (branch of maxillary) and nasociliary nerve (branch of opthalmic)
- Innervation to external skin of nose is supplied by trigeminal nerve
- Special sensory innervation
- Divisions
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