10. Nasal Cavity Flashcards
Identify the various structures representing the general anatomy of everything surrounding the nasal cavity.
- red box: cranial cavity
- yellow : orbits
- blue: nasal cavity (has openings to the pharynx)
- purple: oral cavity (has opening to pharynx)
- green: pharynx (has opening to trachea)
- white: spinal column
- red: larynx with the vocal cords (becomes trachea)
- stripe blue: trachea
- red cylinder: esophagus
- purple circle: plural cavity
What are the 3 parts of the pharynx?
- nasopharynx (behind nasal cavity)
- oropharynx (behind oral cavity)
- laryngopharynx (behind larynx)
Describe the anatomy of the nostrils.
a. roof (formed of ethmoid bone)
b. floor : forms hard palate
c. lateral wall
d. nares (nostrils)
e. choanae (entry to pharynx)
f. conchae: superior, middle, inferior
g. nasal septum =medial wall
What structures form the nasal septum?
perpendicular plate of ethmoid + vomer bone
Identify the various structures of the ethmoid bone.
pink: crista gali
green: orbital plate (medial)
yellow: ethmoid air cells (lined with mucus)
purple: superior and middle nasal conchae
blue: perpendicular plate of ethmoid
red: vomer
How do you know if you’re looking at the medial wall or the lateral wall?
the septum is seen in the medial wall
(trick: if you see outer rim of teeth/mouth: lateral wall, if you see inner rim of teeth: medial wall)
ALWAYS LATERAL WALL IN LAB
Identify the structures of this wall. What wall is this?
medial wall:
pink: vomer bone
blue: septal cartilage
green: perpendicular plate of ethmoid
Identify the various bone structures.
a. nasal cartilage
b. nasal cartilage
c. nasal bone
d. maxilla bone
e. frontal process of the maxilla bone
f. lacrimal bone (drain tears)
g. ethmoid bone
What part of the nose is usually broken?
nasal or septal cartilage
Identify the structure in red.
anterior nasal aperture
Looking at the inferior view, what are the 2 structures shown below?
blue: medial pterygoid plates (part of the sphenoid bone)
red: choanae (between hard palate and sphenoid bone)
Identify the various structures in the medial wall.
a. anterior nasal aperture
b. nasal bone
c. maxilla bone
d. Hard palate = floor = process of maxilla + palatine bone (in green)
e. lacrimal bone
f. ethmoid bone
g. superior nasal chonchae (the smallest of choncae)
h. middle nasal conchae
i. inferior nasal conchae
j. choana
l. sphenoid bone
What forms the hard palate?
palatine bone and process of maxilla
Identify the structure in red.
sphenoethmoidal recess: highest cavity that hold olfactory fibers
What is found beneath each nasal conchae?
- beneath the superior nasal conchae: superior meatus
- beneath the middle nasal conchae: middle meatus
- beneath the inferior nasal conchae: inferior meatus
Identify the paranasal sinuses.
What is their function?
a. frontal sinus
b. maxillary sinuses
c. ethmoid sinuses (in ethmoid air cells)
d. sphenoid sinus
drainage of mucus for swallowing
Identify these two structures.
orange: frontal sinus
yellow: sphenoid sinus
Identify the 2 sinuses shown.
orange: frontal sinus
purple: maxillary sinus
What is the structure shown in blue. What is its function?
semilunar hiatus: drains frontal, ethmoid, maxillary sinuses
Where does the frontal sinus drain into?
frontal sinus drains into the middle meatus by merging into the semilunar hiatus and maxillary sinus
Where do the ethmoid air cells drain into?
they drain into the middle and superior meatuses
What does the arrow on the left point at? what is the function of this structure?
ethmoid bulla = swelling from middle air cells (visible in middle meatus): it is a landmark for the semilunar hiatus that sits just around it
Where does the sphenoid sinus drain into?
into the sphenoethmoidal recess
Where does the maxillary sinus drain into?
drains into the middle meatus
What is orbital floor blowout fracture?
maxilla part of bottom orbital breaks and eye produdes out of the eye socket
What is frontal lobotomy.
to alter and inject things in the frontal lobe via the top orbital plate which is very thin
Identify the various structures and their function. explain the trajectory of tears.
left arrow: lacrimal gland: produces tear that travels laterally into lacrimal puncta
top arrow: lacrimal caniculi = duct that goes into lacrimal duct (found under the inferior nasal conchae)
yellow: lacrimal sac
bottom arrow: inferior nasal conchae
red: nasolacrimal duct: drains tear into inferior meatus
Explain the innervation of the lateral wall of the nasal cavity
- olfactory nerves send out fiber into sphenoethmoidal recess
- ethmoidal nerve (branch of CN V1) does sensory innervation of anterior wall of nasal cavity
- upper half from bottom of nostril up diagonally innervated by CN V1, the bottom is innervated by CN V2
- through the sphenopalatine foramen: nasal n (branch of CN V2) does bottome half
Explain the innervation of the medial wall of the nasal cavity.
- olfactory n (special sensory)
- ethmoidal n that does sensory innervation of anterior nose
- nasopalatine n (branch of CN V2) innervates bottom half and travels through the incisive canal
- upper half from bottom of nostril up diagonally innervated by CN V1, the bottom is innervated by CN V2
Explain the blood supply in the lateral wall of the nasal cavity.
- ethmoidal a: goes to anterior nose
- through the sphenopalatine foramen: sphenopalatine a and anastomose with branches of superior labial a (from facial a)
- through incisive canal: greater palatine anastomose sphenopalatine a
- maxillary a from external carotid a
Explain the blood supply in the medial side of the nasal cavity.
- ethmoidal a does superior and anterior nose anastomes with superior labial a from facial a
- sphenopalatine a: goes through incisive foramen and anastomes with greater palatine a
What is the most common site of nose bleeds?
on medial wall of nasal cavity: ethmoidal a, superior labial a, sphenopalatine a
