The nasal cavity and paranasal sinuses Flashcards
What makes up the nasal septum?
Vomer
Perpendicular plate of ethmoid
Nasal cartilage
What are the openings between the exterior and nasal cavity?
Nares
What name is given the openings onto the nasopharynx?
Choanae
What name is given to the superior part of the nasal cavity?
Olfactory area
What is the name given to the dilated spaces internal to the nares?
Nasal vestibules
Which bones make up the roof of the nasal cavity?
Cribriform plate of ethmoid plate
Nasal bones
Frontal bones
Sphenoid bones
What bones make up the floor of the nasal cavity?
Maxilla
Maxilla’s palatine process
Palatine bone and its horizontal process
What bones make up the lateral wall of the nasal cavity?
Maxilla
Inferior concha
Lacrimal
Ethmoid
Sphenoid
Palatine
What is the role of the conchae?
Increases the surface area of the mucosa
What is the name of the space under the conchae?
Meatus
What is the name of the space superior to the superior concha?
Sphenoethmoid recess
What drains into the sphenoethmoid recess?
Sphenoid recess
What drains into the superior meatus?
The posterior ethmoid air cells
What drains into the middles meatus?
Frontal sinus, Maxillary sinus, anterior and middle ethmoid air cells
What drains into the inferior meatus?
Nasolacrimal duct
What three nerves supply the nasal cavities?
Olfactory nerve
Trigeminal nerve
Facial nerve
What is the role of the olfactory nerve in the nasal cavity?
Receives smell sensations
Where do axons of the olfactory nerve pass through?
Cribriform plate of the ethmoid bone
What two divisions of the trigeminal nerve innervate the nasal cavity?
Ophthalmic nerve
Maxillary nerve
What is the role of the maxillary nerve in the nasal cavity?
General sensation from the postero-inferior division
What is the role of the ophthalmic nerve in the nasal cavity?
General sensation from the antero-superior division
What is the role of the facial nerve in the nasal cavity?
Parasympathetic innervation to secretory glands
What is the major arterial blood supply of the nasal cavity?
Branches of the ophthalmic and maxillary artery
Where do both the maxillary and ophthalmic arteries arise from?
Maxillary - external carotid artery
Ophthalmic - internal carotid artery
What is the clinical term for a nose bleed?
Epistaxis
What is the most common site for epistaxis?
Little’s Area - antero-inferior part of septum
What do veins draining the nose connect with?
Intracranial veins
What are the connecting vessels between the nasal cavity’s veins and intracranial veins called?
Emissary veins
What is the clinical importance of emissary veins?
It is a route by which infection from the nose can spread into the cranial cavity
What lies superior to the roof of the sphenoidal sinus?
The pituitary gland
Name a common complication of nasal infections?
Sinusitis
What is the cause of headaches in sinusitis?
Pressure build-up
What sinus is the most frequently infected and why?
Maxillary sinus due to the position of the openings well above the floor of the sinuses
Which sinuses are often infected together and why?
Frontal and maxillary sinuses
Due to the close proximity of the openings, infections in the frontal sinus can often drain into the maxillary sinus with gravity
What may happen in the case of infection of ethmoid air cells?
May invade the thin wall of bone forming the medial wall of the orbit
Infection may spread to optic nerve, possibly resulting in blindness
Where may a patient experience tenderness while suffering with sinusitis in the frontal sinus?
Upward beneath medial end of superior orbital margin
Where may a patient experience tenderness while suffering with sinusitis in the maxillary sinus?
Anterior wall of maxilla below inferior orbital margin
Where may a patient experience tenderness while suffering with sinusitis in the ethmoid air cells?
Medially against medial end of orbit
Where may a patient experience tenderness while suffering with sinusitis in the sphenoid sinus?
Not palpable
What is rhinitis?
Inflammation of nasal mucosa
Where may infections of the nasal cavity spread to?
Anterior cranial fossa
Nasopharynx
Middle ear
Paranasal sinuses
Conjunctiva
How may infection spread to the anterior cranial fossa and what may this lead to?
Via the ethmoid cribriform plate along sheaths of olfactory nerves
Meningitis
How may infection spread to the nasopharynx?
Via the choanae
How may infection spread to the middle ear?
Eustachian tube
How may infection spread to the paranasal sinuses?
Via the openings of the sinuses
How may infection spread to the conjunctiva?
Via the nasolacrimal duct
What nerves innervate the maxillary sinus and the upper jaw and teeth?
Infra-orbital and alveolar nerves - branches of the maxillary nerve
Where may referred pain be felt in the case of maxillary sinusitis?
Upper jaw and teeth
Where may referred pain be felt in the case of frontal sinusitis?
Scalp as far as the vertex
What nerve innervates the frontal sinus and the skin of forehead and scalp as far as vertex?
Supraorbital nerve
