Nasal and Oral Cavities

Question 1

Describe and define the three main parts of the nasal cavities.

Answer 1

Vestibule- flared portion of nose, contains hair follicles

Respiratory region- largest part of nasal cavity, contains conchae

Olfactory region- superior-most aspect of nasal cavity that contains olfactory epithelium necessary for sense of smell

Question 2

Describe the boundaries of the nasal cavity:
Nasal bone
Maxilla
Lacrimal 
Ethmoid
Inferior nasal concha
Perpendicular plate of...
Medial pterygoid plate of...

Answer 2

Nasal bone (lateral and alar cartilages also)
Maxilla
Lacrimal bone
Ethmoid - superior and middle conchae (cribriform plate)
Inferior nasal concha - a separate bone sitting on top of maxilla and palatine bones
Perpendicular plate of … the palatine bone
Medial pterygoid plate of… the sphenoid bone

Question 3

Describe the boundaries of the nasal cavity:

Describe the three components of the Nasal septum:

Answer 3

(Ethmoid bone, vomer, cartilaginous septum)
Medial wall, usually slightly deviated to one side

Ethmoid bone- perpendicular plate, superiormost portion of septrum
Vomer- inferior region of septum
Cartilaginous septum- anterior region articulates posteriorly with the comer and the perpendicular plate of the ethmoid. Anteriorly related to lateral and alar cartilages.

Question 4

Where are most of the openings?

Where is the opening for nasal lacrimal duct?

Answer 4

most are on lateral wall

nasal lacrimal duct under inf. concha

Question 5

Nasal cavity communicates with other regions of head via various openings and foramina. Describe the following:
Orbit:
Nasopharynx:
Paranasal sinuses:
Anterior cranial fossa:
Pterygopalatine fossa:
Oral cavity:

Answer 5

Orbit: nasolacrimal duct
Nasopharynx: choanae
Paranasal sinuses: meatal openings (air space under concha)
Anterior cranial fossa: cribriform plate and foramen cecum
Pterygopalatine fossa: sphenopalatine foramen
Oral cavity: incisive canal

Question 6

Describe the four paranasal sinuses:
Maxillary
Ethmoidal 
Frontal
Sphenoidal

Answer 6

Maxillary- within body of each maxilla, pyramid shaped, lies beneath the orbit
Ethmoidal - anterior, middle and posterior ethmoidal air cells
Frontal- within frontal bone, bilaterally
Sphenoidal- separated into right/left halves by a midline septum

Question 7

Why might your voice sound funny when you have a cold?

Answer 7

fluid filling up hollow spaces of resonating chambers (vibrations)

Question 8

Describe the blood supply of the nasal cavity.

Answer 8

branches of opthalmic, maxillary, and facial arteries

Question 9

What is the area where one might have nose bleeds? Why?

Answer 9

Kiesselbach’s area. All 3 arteries anastomose here.

Question 10

Describe the differences in facial artery in regards to its supply of lateral wall vs nasal septum.

Answer 10

lateral wall-
facial artery- lateral nasal branch of the facial artery

nasal septum:
facial artery- septal branch of superior labial artery

Question 11

Describe the branches of the three main arteries supplying the nasal cavity:
Opthalmic
Maxillary
Facial

Answer 11

Opthalmic- anterior/posterior ethmoidal arteries
Maxillary- sphenopalatine artery
Facial artery: lateral nasal branches and septal branch of superior labial artery

Question 12

Describe nerve supply.

Answer 12

Olfactory (CN I)
V1 (ant. ethmoidal
V2 (Nasal palatine, Greater/Lesser palatine, maxillary)

Question 13

Describe the boundaries and shape of pterygopalatine fossa.

Answer 13

one of “busiest” regions of skull
inverted “tear-drop” space

Bounded-
Superiorly by body of sphenoid
medially by palatine bone
posteriorly by pterygoid process and greater wing of spehnoid
anteriorly and inferiorly by maxilla

Question 14

What runs through the roof/floor and 4 sides of the pterygopalatine fossa?
Foramen rotundum (roof)
Pterygomaxillary fissure (lateral wall) 
sphenopalatine foramen (medial wall)
inferior orbital fissure (anterior wall)
pterygoid canal (posterior wall) 
palatine canal (floor)

Answer 14

Foramen rotundum - V2

Pterygomaxillary fissure- maxillary artery enters from infratemporal fossa and becomes sphenopalatine a

sphenopalatine foramen- sphenopalatine artery, lateral nasal and nasopalatine nerves

inferior orbital fissure- V2 passes through as infrorbital nerve

pterygoid canal- n and a of pterygoid canacl carrying secretomotor and sympathetic fibers

palatine canal - greater and lesser palatine nerves and descending palatine artery, canal also gives off pharyngeal nerve

Question 15

What is the pharyngeal nerve?

Answer 15

comes off palatine canal

sensory to nasopharynx

Question 16

Of what nature are motor fibers to lacrimal gland?

What does/does not synapse in ganglion?

Answer 16

parasympathetic

parasympathetic fibers synapse. Sympathetic do NOT

Question 17

What two regions can the oral cavity be divided into?

Answer 17

vestibule and oral cavity proper

Question 18

Describe the boundaries of the oral cavity proper:
superior (roof)
inferior (floor)
anterior and lateral
posterior

Answer 18

superior (roof)- hard and soft palate
inferior (floor)- mylohyoid muscle
anterior and lateral- teeth with gingiva and alveolar process
posterior- palatoglossal fold (beginning of the oropharynx)

Question 19

What are the muscles of the soft palate?

Answer 19

levator veli palatini (above palate)
tensor veli palatini (above palate) 
palatoglossus (goes to tongue) 
palatopharyngeus (to pharynx) 
musculus uvulae (just dangles, touches back of tongue, yoddel...)

Question 20

Describe the blood supply of the hard palate:

Answer 20

greater palatine artery (enters through greater palatine foramen and anastomoses with the septal artery after the greater palatine artery passes through the incisive canal)

septal branch of sphenoplatine artery

Question 21

Describe the blood supply of the soft palate:

Answer 21

lesser palatine artery- enters through lesser palatine foramen
ascending palatine artery- branch of facial artery

Question 22

Describe blood supply of dentition.

Answer 22

posterior superior alveolar artery (branch of maxillary) - supplies molars, anastamoses with branches from infraorbital artery

middle and anterior superior alveolar arteries (branches of infraorbital) middle supplies premolars, anterior supplies canine and incisors, anastamose with posterior superior alveolar artery

Question 23

What are mandibular teeth supplied by?

Answer 23

inferior alveolar nerve (branch of V3) and artery (branch of maxillary a)

Question 24

Describe where bolus of food is trapped? What does it do?

Answer 24

vallecula

helps push epiglottis down as you swallow

Question 25

What do the intrinsic muscles of the tongue do? What innervates them?

Answer 25

CN XII Hypoglossal.

change shape of tongue

Question 26

Describe the extrinsic muscles of the tongue:
Where do they attach?
What are they?
What innervates them?

Answer 26

attach- hyoid, mandible, styloid process

genioglossus- bulk
hyoglossus- tilt side to side, retraction. imp for chewing (steak)
styloglossus- pulls back tongue after pushed forward
palatoglossus - helps with swallowing

All by XII except palato which is X

Question 27

Where is the lingual artery located?

Answer 27

lies MEDIAL to hyoglossus muscle. comes off external cartoid artery

(lingual nerve is lateral to hyoglossus muscle)

Question 28

Describe the neve supply of tongue: motor/sensory

Answer 28

motor- all tongue except palatoglossus (X) are XII

sensory
back of tongue( internal laryngeal n, glossopharyngeal n, vallate papillae
front: lingual nerve (general sensory)
chorda tympani CN VII (special sensory)

Question 29

What are the differences between the hard and soft palate?

Answer 29

Like the hard palate, the soft palate also contains palatine glands and is covered by a mucus membrane. Unlike the hard palate, however, the soft palate contains many muscles. These include two which originate above the palate, two which insert below the palate, and one which is completely contained within the palate.

Question 30

Levator veli palatini

OINF

Answer 30

Levator veli palatini:
O: Bony portion of auditory tube (base of skull at union of petrous part of the temporal bone and the sphenoid bone).
I: Palatine aponeurosis (midline connective tissue of soft palate)
F: Elevates palate - prime mover of palate.
N: Pharyngeal plexus by way of the vagus nerve

Note: The palate elevates during swallowing to close off the oral cavity from the nasopharynx, thus preventing food from entering the nasopharynx. The palate also elevates during speech.

Question 31

Tensor veli palatini

OINF

Answer 31

Tensor veli palatini:
O: Scaphoid fossa of medial pterygoid plate of sphenoid bone (also spine of the sphenoid and the cartilage of the auditory tube).
I: Palatine aponeurosis
F: Tenses palate and opens auditory tube
N: Mandibular branch of Trigeminal nerve - V3

Note: The tensor veli palatini runs inferiorly between the medial and lateral pterygoid plates, passes medially by looping around the hamulus of the medial pterygoid plate, and then inserts into the palatine aponeurosis.

Question 32

Palatoglossus OINF

Answer 32

Palatoglossus:
O: Palatine aponeurosis and posterior aspect of hard palate
I: Lateral aspect of tongue
F: Raises tongue to close off oral cavity from oropharynx during swallowing and depresses the soft palate.
N: Pharyngeal plexus by way of the vagus nerve.

Question 33

Palatopharyngeus OINF

Answer 33

Palatopharyngeus:
O: Palatine aponeurosis (posterior edge of hard palate)
I: Posterior aspect of thyroid cartilage, esophagus, lateral wall of pharynx
F: Raises pharynx during swallowing (pulls walls of pharynx superiorly, anteriorly and somewhat medially) and tenses soft palate.
N: Pharyngeal plexus by way of the vagus nerve

Question 34

Drainage into meatus

Answer 34

Sphenoethmoidal recess: region above superior concha - sphenoidal sinus.
Superior meatus: beneath superior concha - posterior ethmoidal air cells.
Middle meatus: beneath middle concha - This meatus contains a fissure called the hiatus semilunaris which runs from anterior to posterior. The ethmoidal bulla is a bulge in this meatus which helps to form the roof of the hiatus. The unciform (uncinate) process helps to form the sharp floor of the hiatus. Structures that drain into the hiatus semilunaris:
Frontal sinus - through the frontonasal duct (to the infundibulum).
Anterior ethmoidal air cells.
Maxillary sinus - this sinus connects to the middle meatus very close to the sinus’ roof.
Structure that drains onto the ethmoidal bulla - middle ethmoidal air cells.
Inferior meatus: orifice of the nasolacrimal duct.