The nose Flashcards
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Innervation?
Facial nerve CN VII
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Cartilage associated with the midline that helps to separate the nose into 2 nostrils?
Cartilage that helps to form the shape of the nostrils ?
septal cartilage
alar cartilage
Blood supply to external nose?
Anterior and posterior ethmoidal arteries (opthalmic)
Sphenopalatine + greater palatine arteries (maxillary)
Superior labial + lateral nasal (septal branch of facial)
Innervation to external nose?
Bridge = opthalmic division (CN V1) –> infratrochlear + external nasal branch of anterior ethmoidal
Alae = maxillary division (CN V2) –> nasal branches of infraorbital
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What bones form the lateral walls of the nasal cavity?
Maxilla,sphenoid bone, ethmoid bone + frontal bone.
Ethmoid bone = forms the superior and middle concha
but inferior concha is a separate bone
Function of medial wall of nasal cavities?
What bones is it formed by?
Medial wall = is the septal wall that separates the nasal passage into 2 cavities
perpendicular plate of ethmoid bone = forms posterior part of septum
Vomer, palatine bones + maxilla = inferior part of septum
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Air passageway through nose?
What helps to equalise pressure on both sides of the tympanic membrane?
Nostrils –> vestibule –> choanae –> nasopharynx
The nasopharynx contains openings of the auditory tubes
Tube leads to middle ear = allows air to be drawn into/expelled from the middle ear to the nasopharynx
This equalizes pressure
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What are the spaces between called?
Function?
Spaces between conchae = meatus i.e. superior, middle + inferior meatus
Filter + warm air, create turbulence
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Space above superior concha called?
Sphenoethmoidal recess
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conchae have been removed
Fill in the blanks
(the infundibulum, semilunar hiatus, ethmoidal bulla and ostium are features of the wall of the meatus)
Label the sinuses + their sensory innervations
What is this photograph showing?
The middle meatus and the curve of the semilunar hiatus around the circular ethmoidal bulla
Label the blood supply to the lateral wall of the nasal cavities
Branch from?
Branches of ophthalmic (ethmoidal), maxillary (sphenopalatine) and external carotid (facial) arteries all supply the lateral wall
Label the blood supply to the medial wall of the nasal cavities
Branch from?
What is the orange area?
Branches of ophthalmic (ethmoidal), maxillary (sphenopalatine) and external carotid (facial) arteries all supply the medial wall (i.e. same as lateral wall)
Kiesselbach’s area - arteries anastamose with each other
Label innervation to the lateral wall of the nasal cavities
Supply derived from?
The lateral walls are supplied with sensory innervation by the ophthalmic and maxillary divisions of the trigeminal nerve.
(the olfactory bulb communicating with the olfactory nerves can also been seen in the roof of the cavity)
Label innervation to the medial wall of the nasal cavities
Supply derived from?
The medial walls are also supplied by the trigeminal nerve.
Label the venous drainage of the nasal cavities
Venous drainage of the nasal cavities?
Nasal cavities drain into the facial vein, pterygoid venous plexus + cavernous venous sinus
Label
Photograph A shows the left hemisection, where the nasal septum is still intact. The septum divides the left and right sides of the nasal cavities and is cartilaginous anteriorly (removed) and bony posteriorly (vomer and ethmoid bone).
Photograph B shows the nasal cavities with part of the septum removed, the middle concha of the nose is now visible.
When the septum is removed, the conchae (or turbinates) of the nose can be seen. The three concha act to cause the air to swirl as it hits the concha and therefore spend longer in the nasal cavity. This helps to warm the air and help it reach the olfactory nerves situated in the superior part of the nose. The nasal cavities are continuous with the nasopharynx. The auditory tube lies in the lateral wall of the nasopharynx (one each side) and communicates with the middle ear to equalise pressure either side of the tympanic membrane.
There are spaces sitting between the conchae, each space is called a meatus. Each meatus lies beneath each concha except for the sphenoethmoidal recess which lies between the sphenoid and ethmoid bones above the superior concha. There is communication between the meatus and the paranasal sinuses that lie in the sphenoid, ethmoid, frontal and maxillary bones.
Photograph A shows the sphenoid air sinus sitting inside the body of the sphenoid bone – it communicates with the sphenoethmoidal recess. This photograph also shows that the posterior ethmoidal air cells open into the superior meatus.
Photograph B shows the close proximity of the ethmoidal air cells to the superior and middle conchae.
Photograph A shows the middle concha being raised from the wall of the nasal cavity. The small holes associated with the ethmoidal bulla and hiatus semilunaris are communications with the anterior and middle ethmoidal air cells, the frontal air cells and the maxillary air cells. There is often variation in the exact position of the openings but all of these sinuses open into the middle meatus.
Photograph B shows the inferior meatus being raised from the wall of the nasal cavity. The nasolacrimal duct that carries excess lacrimal fluid away from the eye opens into the inferior meatus.
Photograph A shows the sphenoid air sinus lying in the body of the sphenoid bone and the pituitary fossa formed in the superior surface of the sphenoid bone. The ethmoidal air cells lie within the ethmoid bone and form many small air pockets instead of one large air filled space. The frontal sinus lies in the frontal bone and may be one membrane lined sinus or may form two almost separate sinuses. The maxillary sinus cannot be seen in this photograph as it lies inside the maxilla.
Photograph B shows the maxillary sinus after the wall of the maxilla has been removed.
