11. Oral Cavity Flashcards
Identify the structure in purple.
oral cavity
Identify the various structures of the oral cavity.
A. ROOF: formed of the hard palate (anterior) and the soft palate (posterior)
B. TONGUE
C. FLOOR = myohyoid muscle and geniohyoid m
D. OROPHARYNGEAL ISTHMUS: opening of oral cavity to pharyn
Identifty these 2 structures of the oral cavity. what is shown in red?
A) lateral wall of the oral cavity: formed of the buccinator muscle : pushes food out of cheeks
B) bolus
red: mucosal membrane: lines all of oral cavity
What is just deep to the mucosal membrane of the oral cavity?
neurovasculature structures = very superficial
Explain the innervation of the tongue.
Identify the 2 lines.
top arrow: terminal sulcus
bottom: lingual septum
What does the blue represent? green?
green: extrinsic muscle (for big motion such as moving tongue side to side)
blue: intrinsic mucsle (for fine movements of tongue)
Identify the various parts.
green: body (mobile)
yellow: root: connected to bone
pink+red: floor:
- red:mylohyoid m
- pink:geniohyoid m
What is the structure in blue? in dotted black line?
blue: mylohyoid line
black: genu
What bone is shown here?
hyoid bone: floating bone that can move up and down: at C3
Identify the muscle in red. What are its attachements? What innervates it? What is the action of the muscle. Where do the 2 mylohyoid attach together and join?
MYLOHYOID MUSCLE
- goes from mylohyoid line to hyoid bone
- innervated by N to mylohyoid (CN V3)
ACTIONS:
- elevates floor of oral cavity
- assist in depressing the mandible
- draws hyoid forward for swallowing
2 mylohyoids attach together at MYLOHYOID RAPHE (in white)
Identify the muscle in pink. What innervates it? What are its attachements? What actions is it responsible for?
GENIOHYOID M
- from genu to hyoid bone
- innervated by C1 anterior ramus
- assist in depression of mandible
- draws hyoid forward for swallowing
Which is a stronger muscle: mylohyoid and geniohyoid muscles?
geniohyoid muscle stronger because its thicker
Where are the muscles of the oral cavity floor found?
under the genioglossus muscle
Identify all the extrinsic muscles of the tongue.
there are 4 extrinsic tongue muscles:
- orange: genioglossus m
- purple: hypoglossus m
- green: styloglossus m
- blue:palatoglossus m
Identify the muscle in orange. What innervates it? What are its attachements? What actions is it responsible for?
GENIOGLOSSUS M
- innervated by the hypoglossal nerve
- originates from the genu
- actions:protrudes tongue (sticks tongue out)
Identify the muscle in purple. What innervates it? What are its attachements? What actions is it responsible for?
HYPOGLOSSUS M:
- innervated by the hypoglossal nerve
- from hyoid bone goes up to tongue
- actions:
bilateral: depresses and retracts tongue
unilateral: flips tongue (side to side)
Identify the muscle in green. What is it innervated by? What are its actions? What are its attachments?
STYLOGLOSSUS M
-innervated by hypoglossal n
- from styloid process to back on tongue
- action:elevates and retracts tongue (avoids food going down to airway when swallowing)
Identify the muscle in blue: attachements, innervation, actions.
PALATOGLOSSUS M
- innervated by vagus n
- from the soft palate
- actions: elevates tongue and closes oropharyngeal isthmus
What forms the first arch of the mouth?
palatoglossus m
What innervates all tongue muscles? is there an exception?
hypoglossal n CN XII innervates all tongue muscle except for palatoglossus which is innvervated by Vagus N CN X
What is the landmark for the hypoglossal nerve?
its under the mylohyoid muscle
Explain the innervation of the tongue.
- hypoglossal nerve (CNXII) runs down to the mandible where it is joined by the anterior ramus C1 and they travel on the hypoglossus m. Goes and innervates all the muscles of the tongue (except palatoglossus) and can be found under the mylohyoid muscle.
- Lingual N (CN V3) travels with the chordae tympani (CN VII) travels to tongue and dips BELOW the submandibular duct after innervating the submandibular gland and innervates sublingual gland
- glossopharyngeal n: general and special sensory of posterior 1/3 tongue
- internal laryngeal n from cn x
Why do patients take sublingual medication?
they diffuse quickly into bloodstream because only mucosal membrane that covers the arteries and veins of tongue = very superficial
What gives the parasympathetic innervation of the sublingual and submandibular glands? for the parotid gland?
chordae tympani for submandibular/sublingual
glossopharyngeal n for the parotid gland
Explain the vasculature of the tongue.
- arteries: common carotid -> external carotid a -> lingual a (Travels along mandible)
- veins: deep lingual v + dorsal lingual v ->lingual v ->internal jugular v
Name the salivary glands.
parotid gland, submandibular gland, sublingual gland
Identify these structures.
A. parotid gland
B. sublingual gland
C. submandibular gland
D. submandibular duct
E. lingual n (cn v3 travelling under the duct)
F.mylohyoid m
What forms the hard palate? Identify them.
HARD PALATE =
palatine process of the maxillary bone (red)
+
horizontal plates of the palatine bone (blue)
identify the soft palate. What composes it?
soft palate (green): muscular fibers and uvula
Identify the structures.
A. incisive foramen (made of right and left incisive canal)
B. greater and lesser palatine foramen
Compare the actions of the oral cavity during chewing vs swallowing.
- CHEWING:
- tongue elevated, soft palate depressed to stop food from going down air hole - SWALLOWING:
- tongue depressed, elevated soft palate (closes nasal pharynx, opens oral pharynx), epiglottis closes (closes larynx), larynx pulls up forward
T/F: eating is only voluntary
false: initiation of eating is voluntary, but once food hits soft palate its involuntary and will automatically be swollen
What innervates the soft palate muscles? are there exceptions?
the vagus nerve innervates all the palate muscles EXCEPT tensor veli palatini: innervated by mandibular n CN V3
Identify the muscle in yellow: attachements, innervagtion, action
LEVATOR VELI PALITINI M
- inn vagus n
- elevates soft palate on each side to prevent food from entering into the nasopharynx
Identify the muscle in green: innervation, attachements, actions.
TENSOR VELI PALITINI M
- innervated by mandibular n CN V3
- curves around the medial pterygoid (has bursa for gliding)
- tenses and flattens palate
(helps the levator veli palitini in elevating palate and preventing the food form entering nasopharynx during swallowing)
Identify the muscle in purple: innervation, attachments, actions.
PALATOPHARYNGEUS M
- inn vagus n
- elevates pharynx to craddle food
What forms the second arch of the mouth? what sits between the 2 arches?
Palatopharyngeus m
-> tonsil sits in between
Explain the blood suppy of the palates.
- maxillary a -> greater palatine foramen -> greater palatine a that supplies the hard palate
- maxillary a -> lesser palatine foramen -> less palatine a that supplies the soft palate
Explain the innervation of the soft and hard palate.
- nasopalatine n (from maxillary n cnv2): exits the incisive canal and innvervates sensory of anterior hard palate
- greater palatine n (from maxillary n) comes out of greater palatine foramen and does posterior sensory innervation of hard palate
- lesser palatine n (from maxillary n) comes out of lesser palatine foramen and does sensory innervation of soft palate
Explain innervation to the teeth and gingiva.
(gingiva: gums)
CN V ->
V2:
- infraorbital n that does sensory of cheek
- superior alveolar n: anterior, middle, posterior
V3: inferior alveolar n -> mandibular foramen (sensory inn of mandible) -> goes out to become mental n through mental foramen
Identify the muscle in green: origin, insertion, innervation, action.
TEMPORALIS m
(muscle of mastication)
ori: temporal fossa
ins: coronoid process of mandible
inn: temporal branches of CN V3
act: elevates and retracts mandible
(muscle of mastication)
Identify the muscle in blue: origin, insertion, innervation, action
MASSETER M
(muscle of mastication)
origin: zygomatic arch
ins: angle of mandible
inn: masseteric branches of CN V3
act: elevates and protrudes mandible
(muscle of mastication)
What is this landmark? Identify its superior, inferior, anterior, posterior, medial and lateral border.
INFRATEMPORAL FOSSA:
- superior border: greater wing of sphenoid bone
- inferior: attachement of medial pterygoid on angle of mandible
- anterior: posterior aspect of maxilla
- posterior: mastoid and styloid process
- medial: lateral pterygoid plate
-lateral: ramus of mandible
What are the 2 muscles found in the infratemporal fossa.
medial and lateral pterygoid muscles
Identify the muscle in blue: origin, insertion, innervation, action.
LATERAL PTERYGOID M
(muscle of mastication)
origin: lateral surface of the lateral pterygoid plate & sphenoid bone
insertion: condylar process of mandible & articular disc of tempomandibular joint
innervation: mandibular n CNV3
bilateral action: protrudes mandible, initiates opening of mouth
unilateral action: lateral movements of mandible
Identify the muscle in green: origin, insertion, innervation, actions.
MEDIAL PTERYGOID MUSCLE
(mastication muscle)
origin: medial surface of lateral pterygoid plate
insertion: angle of mandible
innervation: mandibular n CNV3
action: elevates mandible (closes jaw)
Describe the neurovasculature of the infratemporal fossa.
- ARTERIES:
- Maxillary artery (behind mandible) and off from our external carotid a:
- 1st branch off of maxillary a: middle meningeal a (goes to supply meninges) through the foramen spinosum
- gives of sphenopalatine a (goes to supply nose) - NERVES:
- From the mandibular n CNV3 through the foramen ovale - inferior alveolar n (gives sensory innervation to mandible and chin when it becomes mental n)
- lingual n: sensory to anterior 2/3 of tongue
- buccal n sensory to buccinator m
What anastomoses with the sphenopalatine a and where?
the greater palatine a in the incisive foramen
