Anatomy of nose and nasal cavity Flashcards
What is the external nose?
The prominent part of the nose
What are the parts of the external nose?
Bony part
Cartilaginous part
Vestibule
Which bones form the bony part of the nose?
Nasal bones
Maxilla - frontal process
What lines the vestibule?
Skin
What does the skin of the vestibule contain?
Nasal hair
Sebaceous glands
What are the openings of the external nose?
Nostrils
What is the clinical signifiance of the external nose being prominent?
Nasal bones are commonly fractured
What is the nasal cavity?
Large air-filled space behind the external nose
What lines the nasal cavity?
Mucous membrane
What types of mucous membranes line the nasal cavity?
Olfactory mucous membrane
Respiratory mucous membrane
Where does the olfactory mucous membrane line the nasal cavity?
Roof of nasal cavity
Where does the respiratory mucous membrane line the nasal cavity?
All of nasal cavity that’s not the roof
What does the olfactory mucous membrane contain?
Ends of the CN1 olfactory nerve
What does the respiratory mucous membrane of the nasal cavity contain?
Mucus-producing glands
Cilia
Rich blood supply
What are the functions of the respiratory mucous membrane of the nasal cavity?
Filters the inspired air
Humdifies the inspired air
Warms the inspired air
How does the respiratory mucous membrane filter the inspired air?
Mucus traps particles
cilia waft mucus to oropharynx to be swallowed
How does the respiratory mucous membrane humidify the inspired air?
Mucus glands produce watery secretions
water evaporates into inspired air as water vapour
How does the respiratory mucous membrane warm the inspired air?
Has rich blood supply, which is of core body temperature
heat moves from the blood to the inspired air
How is the nasal cavity adapted for the functions of the respiratory mucous membrane lining it?
Large cross-sectional area
slows flow of air down
Conchae make air flow turbulent, slows flow of air down
increase surface area of respiratory mucous membrane
altogether more contact time with respiratory mucous membrane
What drains into the nasal cavity?
Air flow paranasal sinuses
Tears from nasolacrimal duct
What are the borders of the nasal cavity?
Roof
Floor
Medial wall
Lateral wall
What forms the roof of the nasal cavity?
Frontal bone
Ethmoid bone - crista galli, cribriform plate
Sphenoid bone
What forms the floor of the nasal cavity?
The palate
What forms the medial wall of the nasal cavity?
Posteriorly, ethmoid bone - perpendicular plate
vomer
Anteriorly the septal cartilage
What forms the lateral wall of the nasal cavity?
Conchae
Meatuses
What are conchae?
Bony projections from the lateral wall of the nasal cavity
How many conchae are there?
Three
What are the three conchae?
Superior
Middle
Inferior
What bones do the three conchae arise from?
Superior and middle from ethmoid bone
Inferior is its own bone
What are meatuses?
Air-filled spaces between the conchae
What parts of the nasal cavity do the paranasal sinuses and nasolacrimal duct drain into?
The meatuses
What nerve does sensory innervation to the nose and nasal cavity?
Anteriorly, the opthalmic branch of the CN5 trigeminal nerve
Posteriorly, the maxillary branch of the CN5 trigeminal nerve
