Unit 1 Nasal Cavity and Paranasal Sinuses Flashcards
What are the functions of the nasal cavity?
To provide an airway, olfaction, warming and moistening of inspired air, cleansing of inspired air
What is the proper term for nostrils?
Nares (narus = singular)
What divides the nasal cavity into right and left chambers?
Nasal septum
What is the posterior boundary of the nasal cavity?
Choanae
What is the anterior boundary of the nasal cavity?
Nostrils (nares)
What are the posterior apertures of the nasal cavity which open into the nasopharynx?
Choanae
What is the free end of the nose called?
Tip
What part of the nose connects it to the forehead?
Root
What nose feature bound the nares laterally?
Ala
What forms the roof of the nasal cavity?
Nasal bone, frontal bone, cribriform plate of the ethmoid bone, and the body of the sphenoid bone
What forms the floor of the nasal cavity?
Palatine process of the maxilla and the horizontal plate of the palatine bone
What is the name for the floor of the nasal cavity itself?
Hard palate
What forms the medial wall of the nasal cavity (nasal septum)?
Septal cartilage, perpendicular plate of the ethmoid bone, and the vomer
Why is it important for the septal cartilage to be located anteriorly?
Prevent broken noses
What is “vomer” in Latin?
Plowshare
What is a deviated septum?
When the nasal septum does not lie in the median plane
What can happen when the nasal septum is severely deviated?
It can touch the lateral wall and cause breathing difficulties and/or exacerbate snoring
What causes a deviated septum?
Congenital malformation, birth injury, or postnatal trauma
What forms the lateral wall of the nasal cavity?
Nasal bone, frontal process of the maxilla, lacrimal bone, ethmoid bone, inferior nasal concha, perpendicular plate of the palatine bone, medial pterygoid plate of the sphenoid bone
What structure makes up the nasal conchae?
Thin bone (NOT cartilage)
Which conchae are from the ethmoid bone?
Superior and middle nasal conchae
What are the functions of the nasal conchae?
Increase surface area for more efficient moistening, warming, and cleaning of the air; increases turbulence for olfaction
What can be an anatomical variation among the nasal conchae?
A highest nasal concha can be present above the superior nasal concha (also part of the ethmoid bone)
What is the small space located above and behind the superior nasal conchae that receives the opening of the sphenoid sinus?
Sphenoethmoidal recess
What is the space below the superior nasal concha called that receives the opening of the posterior ethmoidal cells?
Superior meatus
What is the space below the middle nasal concha that receives the openings of the frontal sinus, maxillary sinus, middle ethmoidal cells, and the anterior athmoidal cells?
Middle meatus
What is the rounded projection into the middle meatus called?
Ethmoidal bulla
What is the curved slit lying below the ethmoidal bulla within the middle meatus called that the frontonasal duct, anterior ethmoidal cells, and maxillary sinus open into?
Hiatus semilunaris
What is the space below the inferior nasal concha called that receives the opening of the nasolacrimal duct?
Inferior meatus
What does the nasolacrimal duct connect?
Lacrimal sac of the orbit to the nasal cavity
What is the nasal vestibule?
Area just inside each nostril
What does each nasal vestibule contain?
Hair, sebaceous glands, and sweat glands
What is the significance of the nasal vestibule?
Initial filter of air
Where is the respiratory region of the nasal cavity?
Lower two thirds
After the age of 50, at what rate are olfactory receptors lost?
1% per year
What is the term for loss of olfaction?
Anosmia
What makes up the olfactory region of the nasal cavity?
Superior nasal concha and upper one third of the nasal septum
Where do fibers of the olfactory nerve pass through?
Cribriform plate
Special sensory innervation of the nasal cavity comes from which cranial nerve?
Olfactory (I)
General sensory innervation of the nasal cavity are from which nerves?
Branches of the maxillary and ophthalmic divisions of the trigeminal nerve (CN V)
What is the autonomic innervation of the nasal cavity?
Pterygopalatine ganglion
What is significant about the blood supply to the nasal cavity?
Highly vasularized
The primary blood supply to the nasal cavity are from which arteries?
Sphenopalatine branch of the maxillary artery and the anterior ethmoidal branch of the ophthalmic artery
What is the term for a nosebleed commonly due to high blood supply?
Epistaxis
Which form of epistaxis involves small branches in or near vestibule caused by minor trauma, low humidity, or high altitude?
Mild
Which form of epistaxis involves spurting arterial blood resulting from rupture of the sphenopalatine branch of maxillary artery (at major anastomoses) caused by major trauma?
Severe
What are other causes of both mild and severe forms of epistaxis?
Hypertension (precursor to stroke), blood disorders, cocaine abuse
Where does lymph from the nasal cavity drain?
Into the deep cervical nodes
To where do all paranasal sinuses open?
Nasal cavity
Why is it important for the paranasal sinuses to open into the nasal cavity?
Allowance of sinus drainage
Where is the frontal sinus located?
Within the frontal bone
To where does the frontal sinus open?
Opens into the hiatus semilunaris via the frontonasal duct
Which paranasal sinus drains while sleeping?
Maxillary
Which paranasal sinus is most prone to infection due to poor drainage because of a superior opening?
Maxillary
Which paranasal sinus is the largest?
Maxillary
Where is the maxillary sinus located?
Within the maxilla, lateral to the nasal cavity and inferior to the orbit
Which is the only paranasal sinus that may be present at birth?
Maxillary
Why are sinus infections more prevalent among adults?
Only one paranasal sinus is present at birth
Where is the sphenoidal sinus located?
Within the body of the sphenoid bone opening into the sphenoethmoidal recess
What does “labyrinth” mean?
Maze
What does the term labyrinth refer to?
Ethmoidal sinus
Where is the ethmoidal sinus located?
Within the ethmoid between the orbit and nasal cavity
What are the three groups of cells that make up the ethmoidal sinus?
Posterior, middle, and anterior ethmoidal cells
Where do the posterior ethmoidal cells open into?
Superior meatus
Where do the middle ethmoidal cells open into?
Ethmoidal bulla within the middle meatus
Where do the anterior ethmoidal cells open into?
Hiatus semilunaris within the middle meatus
Where can an infection of the nasal cavity spread?
Paranasal sinuses, nasopharynx, pharyngotympanic tube, nasolacrimal duct to lacrimal apparatus & conjunctive, anterior cranial fossa via cribriform plate, mastoid air cells from middle ear via aditus
What is the proper term for an infection in the paranasal sinus?
Sinusitis
What is the proper term for an infection in the nasopharynx?
Acute pharyngitis
What is the proper term for an infection in the pharygotympanic tube?
Otitis media
What is the proper term for an infection in the nasolacrimal duct?
Conjunctivitis (pink-eye)
What is the proper term for an infection in the anterior cranial fossa via the cribriform plate?
Meningitis or brain abscess
What is the proper term for an infection in the mastoid air cells from the middle ear?
Mastoiditis
What sign can indicate damage to the cribriform plate?
CSF fluid dripping through nose (halo effect can distinguish CSF)
Where is the most common location for an infection to spread to from the nasal cavity?
Nasopharynx (acute pharyngitis)
Where are the locations that are least common for an infection to spread from the nasal cavity to?
Anterior cranial fossa via cribriform plate and mastoid air cells from middle ear
