Anatomy Flashcards
Name the 7 parts of the external nose
Root Dorsum tip ala (wings of the nose) nostril septum philitrum (of upper lip)
What is the function of the nasal septum
To divide the nose into two nasal cavities
Why should adrenaline-containing local anaesthetics not be used near the nasal cartilages
It is a vasoconstrictor and as the cartilage is avascular, it relies on nutrient diffusion from other structures (skin) and so nutrients won’t get to the cartilage if the skin is vasoconstricted
What bones make up the nasal cavity
Frontal Nasal Ethmoid Nasal concha Maxillae (1 either side) vomar sphenoid
What does the vomar bone do
It makes up the septum
What is the roof od the nasal cavity formed from
cribriform plate and crista galli of ethmoid bone
What makes up the lateral wall of the nasal cavity
Superior and middle conchae of the ethmoid bone (either as air cells or orbital plates)
What makes up the septum of the nasal cavity
Perpendicular plate of ethmoid
What separates the brain from the nasal cavity
Only the cribriform plate and crista galli
What type of Le Fort Fracture(s) can disrupt the cribriform plate of the ethmoid bone
2 and 3
What is the danger of the cribriform plate being broken
This would result in a physical connection that would allow infection to spread from the nasal cavity and paranasal sinuses into the anterior cranial fossa
What is one of the main features of a Le Fort Fracture 3
It involves the zygomatic bones and extends up to the superior orbital
Why would a septal haematoma be incised and drained ?
To prevent avascular necrosis of the septal hyaline cartilage which depends on diffusion of nutrients from its attached nasal mucosa
What wall has more features? The medial or lateral wall of the nasal cavity
Lateral
What are both the septum and lateral walls covered by
Mucosa
What are the 3 areas of the nasal cavity lined with
area 1 - keratinised stratified squamous epithelium
area 2 - respiratory epithelium
Area 3 - olfactory mucosa
What is the function of area 1 of the nasal cavity
protection
What is the function of area 2 of the nasal cavity
Mucous secretes goblet cells, cilia, moisture and protection for the rest o the respiratory system
What is the function of area 3 of the nasal cavity
Where you get your sense of smell from
Why can’t you smell anything unless it is aqueous
The nerve cells cannot detect it in any other form
What does cranial nerve 1 do
Gives you the sense of smell
Where are receptor cells found and what is their function
In the olfactory mucosa
they are the 1st neurones in the chain as they pick up the smell
What is the olfactory bulb
A collection of nerve cell bodies (ganglion)
Where does the olfactory tract end
In the temporal lobe
What nerve innervates the nasal cavity
The trigeminal nerve
What nerve supplies the anteriorperior section of the nasal cavity
Ophthalmic (CNVa)
What nerve supplies the posterioinferior section of the nasal cavity
Maxillary (CNVb)
Where does the blood supply to the nasal cavity originate form
The external and internal carotid arteries
What are the 2 main branches of the external carotid artery involved
Facial and Maxillary
What is the main branch of the internal carotid artery
Ophthalmic
Inferior branches of the facial artery supply the nasal cavity. True or False
False - it is the superior branches
Of what artery is the sphenopalatine artery a branch of
Maxillary artery
Of what artery is the ethmoidal arteries a branch of
Ophthalmic artery
What is found in the Kiesselbach’s area
An arterial anastomosis on the nasal septum
Where is a common site of epistaxis (90% of nosebleeds)
Kiesselbach’s area
What is the pneumonic for the arteries that contribute to the Kiesselbach’s area. Name these arteries
LEGS Labial Ethmoidal Greater palatine Sphenopalantine
What are the names of the 3 conchae in the nasal cavities
Superior, middle and inferior
What conchae is not part of the ethmoid
Inferior
What are the conchae covered by
Mucosa
What are the functions of the conchae
Efficient exchange of respiratory gasses - need to be warmed and humidified
Getting drid of toxins we inhale
Why is it a good feature that the air becomes turbulent in the conchae
Helps to get rid of dirt and dust as it will be trapped in the respiratory mucosa
What are the spaces below each conchae called
Meatuses
What is the function of the meatuses
The paranasal sinuses drain into these areas via small holes under the conchae
What are the names of the meatuses
Sphenoethmoidal (recess)
Superior meatus
Middle meatus
Inferior meatus
What forms the nasal septum
Perpendicular plate of the ethmoid bone and the vomer (posteriorly) and the septal cartilages - hyaline (anteriorly)
What forms the floor of the nasal cavity
The right and left maxillae (anteriorly) and the palatine bones (posteriorly)
What makes up respiratory epithelium
pseudo stratified columnar cells with cilia and goblet (mucous -secreting) cells
What is the correct term of the “holes” in the recesses and meatuses of the lateral walls which allow drainage
Ostia
Ostium (singular)
What are the paranasal sinuses
Air-filled spaces within bones
How many sinuses does the frontal bone have
2, separated by bony septum
How many sinuses does the maxillae have
2 (antra)
How many sinuses does the ethmoid bone
2 sets of ethmoidal air cells on either side of the ethmoid bone
How many sinuses does the sphenoid bone
1 or 2
What is the function of the sinuses
Unknown but many theories so far
Eventually, where do all sinuses drain to
The nasal cavity via ostia in the lateral walls of the nasal cavities
Where does the frontal sinus drain to
The middle meatus
Where do the ethmoidal cells drain into
The superior and middle meatuses
Where does the sphenoidal sinus drain into
The sphenoethmoidal recess
Where does the maxillary sinus drain into
The middle meatus
What is the most posterior sinus
Sphenoid sinus
What forms the ethmoidal bulla
Ethmoidal cells push int the nasal cavity and form a bump
Where do most sinuses drain into
The middle meatus
What does the lacrimal gland produce
Tears
Where does lacrimal fluid drain into
The nasolacrimal duct which drains into the inferior meatus of nasal cavity
What causes sinusitis
Inflammation of the mucosa of paranasal sinuses
What are some causes of sinusitis
Infection
Allergy
Autoimmune issues
How can cold weather or smoking cause sinusitis
Cilia of respiratory mucosa waft mucous towards ostia but are slowed down in these conditions = less efficient
What can a viral URTI do in terms of sinusitis
Can cause swelling of mucho, reducing diameter of the ostia
Why is sinusitis painful
Sensation is provided by both CN V1 and V2
Where might pain from sinusitis be referred to
Teeth
What sinus is predisposed to inflammation and why
Maxillary
the ostia are located superiorly in the medial wall of the sinus compared to the floor - the sinus has to drain against gravity
What separates the roots of teeth and the maxillary sinus
A thin layer of mucosa
What might result in an or-antral fistula
Extraction of a tooth
What could spread an infection of a dental abscess into the antrum
The roots of the upper teeth
