2: Anatomy 1 - nose Flashcards
From superior to inferior, name the parts of the external nose.
Root (between eyebrows)
Dorsum (the bridge of the nose)
Apex (tip of the nose)
Septum (separates the right and left nasal cavities)
Philtrum (indentation in the midline, just superior to the upper lip)
Which bone forms the bridge of the nose?
Nasal bone
What are the sides of the nose found on either side of the apex?
Ala
What is the technical name for the nostrils?
Nares
Which two bones make up the nasal septum?
Perpendicular plate of the ethmoid bone
Vomer
Apart from the vomer, which bone forms the superior part of the nasal septum?
Ethmoid bone
What are the two important structures of the roof of the nasal cavity?
Which bone do they belong to?
Cribriform plate
Crista galli
Both part of the ethmoid bone
In which cranial fossa are the cribriform plate and crista galli found?
Anterior cranial fossa
Which ganglia of CN I sit on the cribriform plate of the ethmoid bone and are separated by the crista galli?
Olfactory bulbs
Which structures of the ethmoid bone are found on the lateral wall of the nasal cavities?
Orbital plates
Superior and middle conchae
Ethmoidal air cells
Which part of the ethmoid bone separates the nasal cavity from the bony orbit?
Orbital plate
Which of the three conchae are part of the ethmoid bone?
Superior and middle conchae
Inferior conchae is its own thing
Which particular part of the ethmoid bone makes up the nasal septum?
Perpendicular plate
Is the nasal septum always found in the midline?
No
Slightly deviated in most people
Which type of fracture can damage the cribriform plate of the ethmoid bone?
Which types specifically?
Le Fort fracture
II & III
Why can Type II & III Le Fort fractures cause meningeal infections?
Transmission of bacteria from
nasal cavity and paranasal sinuses
to
anterior cranial fossa
via damaged cribriform plate
The conchae are found on the (medial / lateral) sides of the nasal cavities.
lateral sides
medial side is quite featureless
Which bone joins with the maxilla to form the hard palate at the floor of the nasal cavity?
Palatine bone
Which parts of the sphenoid bone act as insertions for the medial and lateral pterygoids and is found near the nasal cavity?
Pterygoid plates
(remember medial CLOSES the jaw and lateral OPENS it)
The cribriform plate is shaped like a sieve - why?
Allows passage of CN I (olfactory nerve)
The ethmoid air cells form one of the paranasal ___.
paranasal sinuses
Is the inferior concha part of the ethmoid bone?
No
Superior and middle concha ARE
The stratified squamous epithelium at the anterior part of the nasal cavity is ___.
What does this achieve?
keratinised
Stops foreign stuff getting into the nasal cavities
Most of the nasal cavity is lined with respiratory epithelium.
What is this specifically?
CILIATED PSEUDOSTRATIFIED COLUMNAR epithelium with GOBLET CELLS
Don’t forget this
What kind of epithelium is found at the superolateral part of the nasal cavity?
Olfactory epithelium
Where is olfactory epithelium found?
What is its function?
Superolateral nasal cavity
Sense of smell
Which cranial nerve is responsible for smell?
CN I
Olfactory nerve
Which structures do the nerve fibres for CN I pass into once they have gotten up through the cribriform plate?
Olfactory bulbs
What type of fibres are found in CN I?
Special sensory
(Optic nerve is also special sensory because sight is one of the special senses)
Nerve fibres for CN I pass through which part of the ethmoid bone?
Cribriform plate
Where are the receptors for CN I found?
Olfactory epithelium
Superolateral parts of nasal cavities
From the olfactory bulbs, CN I fibres travel to the temporal lobes via which structures?
Olfactory tracts
Are cranial nerves part of the CNS?
No
CNS is brain and spinal cord only
Cranial nerves are technically peripheral nerves (part of PNS)
Which cranial nerves give off the somatic sensory supply for the
a) anterosuperior
b) posteroinferior
parts of the nasal cavity?
a) CN V1
b) CN V2
Which divisions of the trigeminal nerve supply the upper and lower nasal cavities?
a) CN V1 - ophthalmic division
b) CN V2 - maxillary division
Which parts of the nasal cavity are supplied by
a) CN V2
b) CN V1?
a) Posteroinferior
b) Anterosuperior
Which major arteries of the neck give off the vessels supplying the nose?
External carotid artery
Internal carotid artery
Which arteries branch off the
a) external carotid artery
b) internal carotid artery
to supply the nose?
a) Facial artery and Maxillary artery
b) Ophthalmic artery
Which two arteries come off the ophthalmic artery (which comes off internal carotid) to supply the superior part of the nasal cavity?
Anterior ethmoidal artery
Posterior ethmoidal artery
Which artery do the anterior and posterior ethmoidal arteries come off to supply the nasal cavity?
Ophthalmic artery
Which two arteries come off the maxillary artery to supply the posteroinferior part of the nasal cavity?
Sphenopalatine artery
Greater palatine artery
Which artery do the sphenopalatine and greater palatine arteries come off of to supply the nasal cavity?
Maxillary artery
Which artery comes off the facial artery to supply the anterior part of the nasal cavity?
Lateral nasal branch of facial artery
Which arteries come off
a) maxillary artery
b) facial artery
c) ophthalmic artery
to supply the nasal cavity?
a) Sphenopalatine and greater palatine arteries
b) Lateral nasal branch
c) Anterior and posterior ethmoidal arteries
What is Kiesselbach’s area?
Arterial anastomosis in nasal cavity
Is Kiesselbach’s area found on the lateral wall or the nasal septum?
Nasal septum
Kiesselbach’s area is a common site for what?
What is a situation where you may cause this yourself?
Epistaxis (nosebleeds)
NG tube insertion
So you want to guide it laterally at first to avoid the anastomosis on the nasal septum (medial)
What two types of structure are found on the lateral wall of the nasal cavity?
Conchae
Meatuses
What is a concha?
What is their function?
Ridge in wall of nasal cavity
Increase surface area of respiratory epithelium so blood vessels, glands can warm and humidify it
What is a meatus?
Inferior space created by each concha
What are the three important conchae in the nasal cavity?
Which side of the cavity are they found on?
Superior, middle and inferior conchae
Lateral wall
What are the four important meatuses found in the nasal cavity?
Sphenoethmoidal recess
Superior meatus
Middle meatus
Inferior meatus
Which opening is found on the lateral wall of the nasopharynx?
Eustachian tube
communication between middle ear and nasopharynx
Hard palate is found (anteriorly / posteriorly).
Soft palate… “”
Hard palate is anterior
Soft palate is posterior
Which cranial nerve are you going to give sensation to when you insert an NG tube?
What do you need to avoid?
What is the path of the NG tube into the stomach?
CN V2 - maxillary division (inferoposterior)
Kiesselbach’s area (in case you cause an epistaxis)
Nasal cavity > Nasopharynx > Oropharynx > Laryngopharynx > Oesophagus > Stomach
To be confident that it’s in the stomach, how far past the gastroesophageal junction should the NG tube be?
10cm
What allows you to smell air as it passes through the nasal cavity?
Olfactory epithelium
Every bone around the nose has what kind of spaces in it?
Paranasal sinuses
What is the function of paranasal sinuses?
Dunno really
but makes your head lighter, might trap infectious stuff and flush it out
What type of epithelium lines the paranasal sinuses?
What does it secrete?
Respiratory epithelium
Mucus via goblet cells
Which sinuses are associated with the
a) frontal bone
b) maxilla
c) ethmoid bone
d) sphenoid bone?
a) 2 frontal sinuses
b) 2 maxillary sinuses (called antra)
c) 2 sets of ethmoidal air cells
d) 2 sphenoid sinuses
What holes are found in the lateral wall of the nasal cavity and allow mucus to drain from the paranasal sinuses?
Ostia
(each one is called a sinus ostium)
Where does the sphenoid sinus drain?
Sphenoethmoidal recess
Where do the ethmoidal air cells drain?
Superior and inferior meatuses
Where does the frontal sinus drain?
Middle meatus
Where do the antra drain?
Middle meatus
Where do the nasolacrimal ducts drain?
Inferior meatus
(only thing draining into inferior meatus is lacrimal fluid)
Where do the
a) nasolacrimal ducts
b) sphenoid sinuses
c) frontal sinuses
d) ethmoidal air cells
e) maxillary sinuses / antra
drain?
a) Inferior meatus (only structure which drains here)
b) Sphenoethmoidal recess
c) Middle meatus
d) Superior and middle meatuses
e) Middle meatus
Why do you get a runny nose when you cry?
Increased drainage of lacrimal fluid through inferior meatus
Which then comes out your nose
What is sinusitis?
Inflammation of the respiratory epithelium lining the sinuses
What are some causes of sinusitis (think VINDICATE)?
Infection
Inflammation
Autoimmune (including allergy)
The problem in sinusitis usually revolves around the failure of mucus drainage through what?
Ostia
If the ostia of sinuses are closed off, what accumulates in the sinuses?
Mucus +/- infection
What cranial nerves supply the somatic sensory fibres which will be stimulated in sinusitis?
CN V1 and V2
Where may sinusitis pain be referred?
Why?
Teeth
because teeth are also supplied by CN V1 and V2
Why are the maxillary sinuses / antra more likely to become inflamed than other sinuses?
Ostia is superior
So mucus has to drain against gravity
What spaces can be connected by a fistula following dental surgery?
Oral cavity and maxillary sinus
