Pterygopalatine Fossa and Nasal Cavity

Question 1

What comprises the bony part of the nose?

Answer 1

• nasal bones
• frontal process of maxilla
• nasal part of frontal bone and nasal spine
• bony part of nasal septum

Question 2

What comprises the cartilagenous part of the nose?

Answer 2

• 2 lateral cartilages
• 2 alar cartilages
• septal cartilage (nasal septum)

Question 3

What structures comprise the external nose?

Answer 3

• glabella
• nasal bone
• frontal process of maxilla
• lateral nasal cartilage
• major alar cartilage
• minor alar cartilage

Question 4

• except for the vestible of the nose (considered external), the nasal cavity is lined with _____ _______
• _____ _______ is firmly connected to periostium of bony parts of the nasal cavity and the perichondrium of the cartilagenous nasal components
• the areas lined with nasal mucosa constitute the ________ _____ (inferior 2/3) and the _______ _____ (superior 1/3)

Answer 4

• except for the vestible of the nose (considered external), the nasal cavity is lined with nasal mucosa
• nasal mucosa is firmly connected to periostium of bony parts of the nasal cavity and the perichondrium of the cartilagenous nasal components
• the areas lined with nasal mucosa constitute the respiratory area (inferior 2/3) and the olfactory area (superior 1/3)

Question 5

the olfactory area has specialized nasal mucosa that contains the peripheral nerve endings from the ______ ____ (CN I) for special sense, ______

Answer 5

the olfactory area has specialized nasal mucosa that contains the peripheral nerve endings from the olfactory nerve (CN I) for special sense, olfaction

Question 6

What is the difference in location of the pharyngeal and palatine tonsils? How can these be visualized respectively?

Answer 6

• pharyngeal tonsils are located near the opening of the nasal cavity into the pharynx; when these tonsils become enlarged they may interfere with breathing and are called adenoids; they can be visualized by rhinoscopy
• palatine tonsils are the ones that are located near the opening of the oral cavity into the pharynx; they can be visualized unaided when opening the oral cavity

Question 7

What are the following boundaries of the nasal cavity:

• roof:
• floor:
• medial wall:
• lateral wall:

Answer 7

• roof: frontal bone, ethmoid bone, sphenoid bone
• floor: palatine process of maxilla, horizontal plate of palatine bone
• medial wall: nasal septum (perpendicular plate of ethmoiod, vomer, septal cartilage, nasal crests of maxillary and palatine bones)
• lateral wall: superior, middle, and inferior nasal conchae

Question 8

What are the “gaps” associated with the nasal conchae and their associated sinuses?

Answer 8

• sphenoethmoid recess (most superior): sphenoid sinus
• superior meatus (middle, below sphenoethmoid): posterior ethmoid sinus
• middle meatus (middle, below superior meatus): anterior and middle ethmoid sinus, frontal sinus, maxillary sinus
• inferior meatus (most inferior): nasolacrimal duct

Question 9

Which passages are associated with which openings?

Answer 9

• sphenoethmoid recess: opening of sphenoid sinus
• superior nasal meatus: openings of ethmoidal sinuses
• middle nasal meatus: opening of frontal sinus (maxillary sinus also opens into middle meatus in posterior part of semilunar hiatus at the maxillary ostium (below ethmoid bulla)
• inferior nasal meatus: opening of nasolacrimal duct

Question 10

What is the vasculature to the nasal cavity?

Answer 10

• most of the blood supplied to lateral and medial walls is from branches of the ophthalmic A. > anterior and posterior ethmoid As.
• maxillary A. > sphenopalatine and greater palatine As.
• facial A. > superior labial A. and lateral nasal branches

(venous drainage to sphenopalatine, facial, and ophthalmic Vs.)

Question 11

What is the location and associated vasculature a/w the most common cause of epistaxis?

Answer 11

Kiesselbach area is where all five As. (anterior and posterior ethmoid As., sphenopalatine A., greater palatine A., superior labial A., and lateral nasal branches) come together in a capillary bed that can bleed profusely

Question 12

• largest sinus
• drains via maxillary ostium into middle meatus
• arterial supply: superior alveolar branches of maxillary A. and greater palatine A.
• innervation: superior alveolar nerve branches

Answer 12

maxillary sinus

Question 13

• ethmoid air cells located between orbits
• anterior and middle ethmoidal cells drain into middle meatus
• posterior ethmoidal cells drain into superior meatus
• arterial supply: ethmoidal A. from opththalmic A.
• innervation: nasociliary nerves (CN V1)

Answer 13

ethmoid sinus

Question 14

• sinus that is unevenly divided by bony part of nasal septum
• drains via sphenoethmoidal recess
• arterial supply: posterior ethmoidal A. from ophthalmic A.
• innervation: posterior ethmoidal nerve from nasociliary

Answer 14

sphenoid sinus

Question 15

• sinus that is between outer and inner tables of frontal bone, posterior to superciliary arches
• drains via frontonasal duct into semilunar hiatus of middle meatus
• arterial supply: supraorbital A. and anterior ethmoidal A. (ophthalmic A.)
• innervation: supraorbital nerves (CN V1)

Answer 15

frontal sinus

Question 16

Where is the pterygopalatine fossa located?

What are its borders?

What are its openings?

Answer 16

• located inferior to the apex of the orbit
• boarders
  
  • anterior: maxillary tuberosity
  • posterior: pterygoid process of sphenoid (lateral plate)
  • medial: perpendicular plate of palatine bone
  • lateral: opens into infratemporal fossa via pterygomaxillary fissure
  • roof: (incomplete) greater wing of sphenoid
  • floor: pyramidal process of palatine bone
• openings
  
  • superior: opens into inferior orbital fissure
  • inferior: closed except for palatine foramen

Question 17

What are the openings of the pterygopalatine fossa?

Answer 17

• fissures
  
  • inferior orbital fissure
  • pterygomaxillary fissure
• foramina
  
  • spheno-palatine foramen
  • foramen rotundum (maxillary N., CN V2 runs inward)
• canals
  
  • pharyngeal canal
  • pterygoid canal
  • pterygopalatine canal

Question 18

What neurovascular structures pass into pterygopalatine fossa?

Answer 18

• orbit (inferior orbital fissure):
  
  • nerves: infraorbital, zygomatic, orbital branches (from CN V2)
  • vessels: infraorbital A. and Vs. and inferior ophthalmic V.
• middle cranial fossa (foramen rotundum):
  
  • nerves: maxillary N. (CN V2)
• base of skull (pterygoid canal)
  
  • nerves: N. of pterygoid canal (greater and deep petrosal Ns.)
  • vessels: A. of pterygoid canal and Vs.
• palate
  
  • greater palatine canal
    
    • nerves: greater palatine N.
    • vessels: descending palate A. and greater palatine A.
  • lesser palatine canals
    
    • nerves: lesser palatine Ns.
    • vessels: lesser palatine As. (terminal branches of descending palatine A.)
• nasal cavity (sphenopalatine foramen):
  
  • nerves: medial and lateral posterior superior and posterior inferior nasal branches (from nasopalatine N., CN V2)
  • vessels: sphenopalatine A. and Vs.

Question 19

Describe the pathway of the trigeminal N. (maxillary N., CN V2) from pterygopalatine fossa to lacrimal gland:

Answer 19

• maxillary N. (V2) > pterygopalatine nerves and zygomatic N.
• zygomatic N. > zygomaticofacial N. and zygomaticotemporal N.
• zygomaticotemporal N. > communicating branch conveys parasympathetic fibers to lacrimal N. (CN V1)

Question 20

Describe the pathway of the parasympathetic fibers within the pterygopalatine fossa:

Answer 20

• parasympathetic fibers to pterygopalatine ganglion are from facial N. (CN VII) via greater petrosal N.
• greater petrosal N. joins deep petrosal N. to form the N. of the pterygoid canal
• parasympathetic fibesr from greater petrosal N. synapse in pterygopalatine ganglion

Question 21

Describe the pathway of the sympathetic fibesr within the pterygopalatine fossa:

Answer 21

• deep petrosal N. arises from the internal carotid plexus and conveys postsynaptic sympathetic fibers which join branches of the maxillary N. via the pterygopalatine ganglion (do not synapse there)
• presynaptic sympathetic fibers are from the superior cervical ganglion

Question 22

What are the nervous structures within the pterygopalatine fossa?

Answer 22

• infraorbital N.
• zygomatic N.
• orbital branches (V2)
• maxillary N. (V2)
• N. of pterygoid canal (greater and deep petrosal Ns.)
• greater palatine N.
• lesser palatine N.
• medial and lateral superior and posterior inferior nasal branches from nasopalatine N. (V2)

Question 23

What are the branches of the maxillary A. through the pterygopalatine fossa?

Answer 23

• descending palatine A. (9) >
  
  • greater palatine A. > hard palate
  • lesser palatine A. > soft palate, palatine tonsil, pharyngeal wall
• posterosuperior alveolar A. (10) > maxillary molars, maxillary sinus, gingiva
• infraorbital A. (11) > maxillary alveoli
• A. of pterygoid canal (12)
• sphenopalatine A. (13) >
  
  • lateral posterior nasal As. > lateral wall of nasal cavity, choanae
  • posterior septal branches > nasal septum

*all derived from maxillary A.*

Question 24

levator vali palatini M.

• origin:
• insertion:
• action:
• innervation:

Answer 24

levator vali palatini M.

• origin: petrous part of temporal bone, inferior/cartilaginous part of auditory tubes
• insertion: palatine aponeurosis
• action: elevates soft palate (during swallowing)
• innervation: pharyngeal plexus (CN X)

Question 25

tensor vali palatini M.

• origin:
• insertion:
• action:
• innervation:

Answer 25

tensor vali palatini M.

• origin: scaphoid fossa of pterygoid process, spine of sphenoid bone, sembranous wall of auditory tube
• insertion: palatine aponeurosis
• action: tenses palatine aponeurosis, opens pharyngeal opening of auditory tube (during swallowing)
• innervation: nerve to medial pterygoid (of mandibular N., CN V3)