Nasal Cavities and Paranasal Sinuses Flashcards
List the parts of the external nose
Root Dorsum Apex (tip) Ala (wings) Nares (nostrils) Septum Philtrum (upper lip)
State the two main types of tissue making up the nose
Nasal bone
Hyaline cartilage
State the investigation of choice for nasal fracture
No investigation
What forms the roof and floor of the nasal cavity respectively?
Cribiform plate and crista galli (anterior cranial fossa)
Palate
What forms the lateral wall of the nasal cavity?
Superior and middle conchae
Air cells
Orbital plate of ethmoid
Inferior conchae
What forms the septum of the nasal cavity?
Perpendicular plate of ethmoid
Vomer
Septalhyaline cartilage
Le Forte fractures 2 and 3 disrupt which part of the ethmoid?
Cribiform plate of ethmoid
What is the consequence of Le Forte Fractures?
Danger of infection spreading from nasal cavity and paranasal sinuses into anterior cranial fossa (cribiform plate and dura are only protection)
List the types of mucosa in the nasal cavity
Keratinised SSE
Respiratory epithelium
Olfactory mucosa
Outline the neurone chain of the olfactory nerve starting at receptors
Receptor cells 1ST NEURONE –>
Cribiform plate of ethmoid in olfactory mucosa –>
Olfactory bulb (ganglion) 2ND NEURONE –>
Olfactory tract –>
Temporal lobe
The trigeminal nerve supplies sensory innervation to the nasal cavity. State the area supplied by each of it’s branches
V1: Anterosuperiorly
V2: Posteroinferiorly
Outline the area of the nasal cavity supplied by the external carotid artery, and give branches in order
EXTERNAL CAROTID
- Facial artery –> lateral nasal branch (lateral wall) and septal branch of superior labial artery (medial wall)
- Maxillary artery –> sphenopalatine (medial and lateral wall) and greater palatine arteries (medial wall)
Outline the area of the nasal cavity supplied by the internal carotid artery, and give branches in order
INTERNAL CAROTID
Ophthalmic artery –> anterior and posterior ethmoidal arteries (medial and lateral wall)
What is the significance of Kiesselbach (Little’s) area
Arterial anastomosis on nasal septum which is a common site for epistaxis
The conchae of the nasal cavity are all made up of one bone. True/ False?
False
Inferior conchae is it’s own bone, superior and middle conchae are one bone
State the name for the space under each conchae
Meatus
List the meatuses of the nasal cavity from superior to inferior
Sphenoethmoidal recess
Superior meatus
Middle meatus
Inferior meatus
How does a correctly placed nasogastric tube appear on imaging?
In midline to level of diaphragm
Tip should be visible 10cm beyond GOJ (in stomach)
List the functions of the nasal cavities
Conduit for air into nasopharynx Filters air via vibrissae Humidifies air Warms inspired air Sense of smell
List the paranasal sinuses, and the drainage site for each
2 x frontal sinuses —> middle meatus
2 x maxillary sinuses —> middle meatus
2 x ethmoid air cells —> superior and middle meatuses
2 x sphenoid sinuses —> sphenoethmoidal recess
The maxillary sinuses are also known as…
Antra
What type of tissue lines the paranasal sinuses?
Mucous secreting respiratory mucosa
What secretes mucous from the paranasal sinuses into the nasal cavities?
Ostia in lateral wall of cavities
Outline the drainage pathway for lacrimal fluid
Lacrimal gland —> Tears —> Wash over eye —> Nasolacrimal duct —> Inferior meatus
What is the only fluid that drains into the inferior meatus?
Lacrimal fluid
What is sinusitis?
Inflammation of mucosa of paranasal sinuses
What nerves cause pain to be felt in sinusitis?
CN V1 and V2
The trigeminal nerve refers pain to…
Maxilla/ mandible
Antral mucosa
Teeth
State the most common site for sinusitis. Why is this the most common?
Maxillary sinuses
They are predisposed to inflammation as ostia are located superior in the medial wall (not in the floor), therefore mucous drains against gravity
List a common complication of teeth extraction. How is this managed?
Oroantral fistula
Roots of teeth spread infection of dental abscess to the antrum causing sinusitis
Surgery if persistant
