Lecture 14-Nose And Paranasal Sinuses Flashcards
What are the functions of the nose and nasal cavity?
- smell
- route for inspired air
- filters inspired air
- moistens and warms air
- resonating chamber for speech
What does inspired air enter through?
Vestibule
What is the vestibule lined with and what does it contain?
Lined with skin and contains hair within the nostrils and sebaceous glands
Which bones make up the external nose?
Nasal bone and frontal process of the maxilla
What allows time for filtering, warming and humidifying air in the nasal cavity?
Large SA which slows the air flow, allowing time for the above
What is the nasal cavity lined with?
Mucous membrane
What are the two different types of mucous membrane lining the nasal cavity and what are their functions?
- olfactory mucous membrane with receptor ends of CN I
- Respiratory mucous membrane lined by pseudostratified columnar ciliated epithelium to filter, humidify and warm the air
What forms the floor of the nasal cavity?
Hard palate
What forms the lateral wall of the nasal cavity?
- bony projections=conchae/turbinates
- meatuses
What drains below the meatuses?
Paranasal sinuses and nasolacrimal ducts
What forms the roof of the nasal cavity?
Frontal bone, crista galli, cribriform plate of ethmoid bone and sphenoid bone
What forms the medial wall of the nasal cavity?
Septal cartilage and nasal septum (perpendicular plate of ethmoid bone and vomer bone)
What is a septal haematoma?
Trauma to nose -> buckling of septum and shearing of blood vessels -> blood accumulates between perichondrium and cartilage
What can an untreated septal haematoma lead to?
Avascular necrosis of the septum -> saddle-nose deformity
What is the nerve innervation to the nose and nasal cavity?
Most is CN Vb but some from CN Va
What are nasal polyps?
Fleshy, benign swellings of nasal mucosa
What are the symptoms of nasal polyps?
- blocked nose
- watery rhinorrhoea
- post-nasal drip
- decreased smell and taste
- unilateral blood-tinged secretion
What is rhinitis?
Inflammation of nasal mucosal lining
What can cause rhinitis?
Simple acute infection (cold) or allergy
What are the symptoms of rhinitis?
- Nasal congestion
- rhinorrhoea
- sneezing
- nasal irritation
- postnasal drip
If the discharge in kids is smelly and blood-stained, what is the most likely cause?
Foreign body
What is the arterial supply to the nasal mucosa?
Ophthalmic artery and maxillary artery
What is epistaxis?
Nose-bleed
What is the most common source of epistaxis?
Kiesselbach’s plexus/Little’s area
