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1. To drain an abscess (a closed collection of pus) affecting the
cheek area, an emergency room physician used local anesthesia
for the surgery. Which of the following nerves must be
anesthetized because it carries pain sensation from the cheek
area?
buccal (V3)
buccal (VII)
inferior alveolar
lingual
mental
2. A patient who experienced bilateral anterior dislocation of the jaw
(temporomandibular joints) could not swallow or talk since the
mouth was held open. What is the position of the condyles of the
mandible as a result of the dislocation?
against the external acoustic meatus
against the anterior slope of the articular eminence
against the posterior slope of the articular eminence
in the mandibular fossa
in the pterygoid fossa
3. In reducing an ankylosis of the TMJ, a surgeon provoked an
intense hemorrhage by lacerating the artery coursing transversely
just medial to the neck of the condyle. Which artery was involved
in the accident?
Buccal
External carotid
Maxillary
Middle meningeal
Superficial temporal
4. The muscle which separates the submandibular triangle from the
paralingual space is the:
Digastric, posterior belly
Hyoglossus
Mylohyoid
Stylohyoid
Styloglossus
5. The predominant muscle most associated with retraction of the
mandible is the:
lateral pterygoid
masseter
medial pterygoid
temporalis
mylohyoid
6. At the temporomandibular joint (TMJ), hinge movements occur
between the:
condyle and articular eminence
articular disc and articular eminence
condyle and articular disc
articular disc and articular cavity
condyle and articular cavity
7. A 38-year-old patient complained of acute dental pain. The
attending dentist found penetrating dental caries (dental decay)
affecting one of the mandibular molar teeth. Which nerve would
the dentist need to anesthetize to work on that tooth?
Lingual
Inferior alveolar
Buccal
Mental
Mylohyoid
8. Incapacity to protrude the mandible indicates a dysfunction of
which muscle?
Anterior belly of digastric
Buccinator
Lateral pterygoid
Mylohyoid
Temporalis
9. Damage to the facial nerve near the stylomastoid foramen would
likely cause each of the following motor deficits EXCEPT:
Paralysis of the buccinator muscle
Inability to whistle
Paralysis of the muscles that elevate the mandible
Inability to close the lips
10.
The lesser petrosal nerve carries preganglionic
parasympathetic fibers to the:
Geniculate ganglion
Otic ganglion
Submandibular ganglion
Ciliary ganglion
11.
What bony feature of the mandible can be used to find and
palpate the facial artery?
Oblique line
Mental trigone
Angle
Premasseteric notch
12.
Which of the following suprahyoid muscles would be
paralyzed if the inferior alveolar nerve were severed at its origin?
Geniohyoid m.
Hyoglossus m.
Mylohyoid m.
Stylohyoid m.
13.
Which nerve is endangered during surgical removal of an
impacted third mandibular molar tooth?
Hypoglossal n.
Glossopharyngeal n.
Inferior alveolar n.
Lingual n.
14.
After the mandibular condyle is moved forward onto the
articular eminence (e.g., by opening the mouth widely), what
muscle can then retract the mandible?
Superficial head of masseter m.
Deep head of masseter m.
Posterior part of temporalis m.
Anterior part of temporalis m.
15.
Two nerves usually emerge from between the two heads of
the lateral pterygoid muscle: the anterior deep temporal nerve and
the:
Masseteric n.
Buccal n.
Lingual n.
Inferior alveolar n.
16.
The chorda tympani enters the infratemporal fossa after it
exits the:
Stylomastoid foramen
Foramen spinosum
Foramen lacerum
Petrotympanic fissure
17.
Paralysis of which of the following muscles would impede
retraction of the mandible?
Buccinator
Lateral pterygoid, lower portion
Lateral pterygoid, upper (sphenomeniscus) portion
Medial pterygoid
Temporalis
18.
A cranial fracture through the foramen ovale that
compresses the enclosed nerve, will have an effect on all muscles
EXCEPT :
Tensor tympani
Masseter
Buccinator
Mylohyoid
19.
Temporalis
Which muscle is also known as the sphenomeniscus?
Inferior head of the lateral pterygoid
Masseter
Medial pterygoid
Superior head of the lateral pterygoid
Temporalis
20.
Forward movement of the condyle of the mandible during
wide opening of the jaws is accomplished mainly by the:
anterior part of temporalis muscle
lateral pterygoid muscle
masseter muscle
medial pterygoid muscle
posterior part of the temporalis muscle
21.
To drill a mandibular tooth without causing undue pain, a
dentist has injected an anesthetic into the space located between
the medial pterygoid muscle and the mandible near the lingula.
Given the nerves passing through the immediate vicinity of the
injection site, where would one expect anesthesia in addition to the
mandibular teeth?
back of tongue
external ear
maxillary incisor teeth
skin of chin
22.
upper lip
The middle meningeal artery:
enters the skull through the foramen ovale
passes through a split in the trunk of the mandibular nerve (V3)
is typically a branch of the second part of the maxillary artery
supplies blood to the temporal lobe of the brain
usually arises deep to the neck of the mandible
23.
The surgical removal of a metastatic tumor in the
infratemporal fossa caused an intense hemorrhage. The surgeon
clamped the main source of arterial supply to the area, which is
the:
Internal carotid
Lingual
Maxillary
Posterior auricular
Superficial temporal
24.
In acute inflammation (arthritis) of the TMJ, the muscle most
likely to be affected by the inflammatory process is the:
Temporal
Medial pterygoid
Masseter
Lateral pterygoid
25.
In explaining the pain caused by the drilling of a mandibular
molar tooth crown to a freshman medical student, a dentist
identified the nerve conducting the pain sensations as the:
Lingual
Mylohyoid
Inferior alveolar
Buccal
26.
The temporomandibular joint is characterized by all
EXCEPT:
A capsule strengthened by ligaments on its lateral side only
A completely flat surface for its gliding action
An articular disc
Extracapsular ligaments
Two joint cavities of different shapes
27.
In dislocation of the jaw, displacement of the articular disc
beyond the articular tubercle of the temporomandibular joint results
from excessive contraction of which muscle?
Buccinator
Lateral pterygoid
Medial pterygoid
Masseter
28.
Temporalis
Sympathetic fibers reach the tongue by way of the:
lingual nerve
maxillary artery
hypoglossal nerve
lingual artery
glossopharyngeal nerve
29.
After a radiograph revealed a sialolith (stone) in a patient's
right submandibular duct, the surgeon exposed the duct via an
intraoral approach. In this approach, what tissues or structures
must be cut through?
Mucous membrane only
Mucous membrane and genioglossus muscle
Mucous membrane and mylohyoid muscle
Mucous membrane and hyoglossus muscle
30.
Damage of the lingual nerve before it is joined by the chorda
tympani in the infratemporal fossa would cause loss of:
general sensation to the anterior two thirds of the tongue
general sensation to the posterior one third of the tongue
secretion of the submandibular gland
taste sensation from the anterior two thirds of the tongue
31.
taste sensation from the posterior one third of the tongue
The teeth and gums separate the oral cavity proper from the:
Nasal cavity
Oral vestibule
Oropharynx
Paralingual space
Submandibular space
Description for the following questions: Examination of a patient
with an ulcerative carcinoma of the posterior third of the tongue
revealed bleeding from the lesion and difficulty swallowing
(dysphagia).
32.
The bleeding was seen to be arterial; which of the following
arteries was involved?
Deep lingual
Dorsal lingual
Facial
Sublingual
Tonsillar
33.
The difficulty in swallowing was due to involvement of which
muscle that elevates the tongue?
Genioglossus
Hyoglossus
Styloglossus
Stylohyoid
Stylopharyngeus
34.
Cutting of the hypoglossal nerve in the hypoglossal canal
would not interrupt the nerve supply to the:
Hyoglossus muscle
Genioglossus muscle
Palatoglossus muscle
35.
Styloglossus muscle
The contents of the paralingual space do NOT include the:
Hypoglossal nerve
Lingual artery
Lingual nerve
Submandibular gland
Sublingual gland
36.
A patient is unable to taste a piece of sugar placed on the
anterior part of the tongue. Which cranial nerve is most likely to
have a lesion?
Facial nerve
Glossopharyngeal nerve
Hypoglossal nerve
Trigeminal nerve
Vagus nerve
37.
The chorda tympani contains which component before it
joins the lingual nerve?
Preganglionic sympathetics
Postganglionic sympathetics
Preganglionic parasympathetics
Postganglionic parasympathetics
Taste fibers to the posterior third of the tongue
38.
The cell bodies of the taste fibers from the anterior two-thirds
of the tongue are located in the:
Geniculate ganglion
Otic ganglion
Pterygopalatine ganglion
Submandibular ganglion
Trigeminal ganglion
39.
Which of the following structures is located in the vestibule of
the oral cavity?
Tongue
Opening of the parotid duct
Opening of the submandibular duct
Sublingual fold
Uvula
40.
When one presses the tongue tip against the anterior
(incisor) teeth, which of the following muscles must contract?
Styloglossus
Hyoglossus
Genioglossus
Superior longitudinal
Verticalis
41.
The muscle responsible for raising the floor of the mouth in
the early stages of swallowing is the:
genioglossus
geniohyoid
hyoglossus
mylohyoid
palatoglossus
42.
The cell bodies of the postganglionic parasympathetic
neurons innervating the sublingual gland are found in which of the
following ganglia?
ciliary
otic
submandibular
superior cervical
trigeminal
43.
A 46-year-old female patient comes to the emergency
department complaining of pain in the area just below her
mandible on the right side of her face. She says that the pain is
particularly severe when she eats. The area of the submandibular
gland is tender and swollen, as is the area in the floor of her mouth
lateral to the tongue. You suspect a stone in the submandibular
duct, and a plain film radiograph shows a density in that region
consistent with a stone. In order to remove the stone, the duct
must be incised in the floor of the mouth. What nerve, that loops
around the duct, is in danger in such an incision?
Chorda Tympani
Glossopharyngeal
Hypoglossal
Internal branch of the superior laryngeal
Lingual
44.
In accessing the submandibular gland in the submandibular
triangle, what vessel coursing through the gland and triangle would
need to be protected?
External jugular vein
Facial artery
Maxillary artery
Retromandibular vein
Superior thyroid artery
45.
All of the following may be found in the paralingual space
EXCEPT:
Hypoglossal nerve
Lingual nerve
Sublingual gland
Submandibular gland duct
Superficial lobe of the submandibular gland
1. The correct answer is:
Buccal (V3)
The buccal nerve is a branch of the mandibular division of the trigeminal
nerve that transmits sensory information from the skin of the cheek area
and the oral mucosa of the cheek. The buccal nerve is NOT the same as
the buccal branches of the facial nerve, which are motor nerves that
innervate the buccinator and the facial muscles of the upper lip. The
buccal branches of the facial nerve do not have a sensory component!
The inferior alveolar nerve is another branch of V3 that penetrates the
mandibular foramen and is the sensory nerve for the mandible and all
mandibular teeth. This is the nerve that dentists must anesthesize when
they are working on the mandibular teeth. The lingual nerve is also a
branch of V3--it transmits general sensation from the tongue. The lingual
nerve also receives the chorda tympani, a branch of the facial nerve,
which provides the lingual nerve with preganglionic parasympathetic
fibers for the submandibular and and sublingual glands, as well as the
taste fibers for the anterior 2/3 of the tongue. Finally, the mental nerve is
a branch of V3 from the inferior alveolar nerve--it provides sensory
innervation to the skin of the chin and lower lip.
2. The correct answer is:
eminence
against the anterior slope of the articular
The TMJ may dislocate anteriorly due to excessive contraction of the
lateral pterygoids. This could happen if someone yawned too much or
took a large bite of food. So, you want to look for the answer here that
represents anterior movement of the jaw. Answer B, against the anterior
slope of the articular eminence, is anterior to the normal position of the
mandible, so that's the correct answer.
The external acoustic meatus is posterior to the normal position of the
mandible, so you know that the mandible would not touch this structure if
it dislocated anteriorly. In its normal position, the head of the mandible is
near the posterior slope of the articular eminence and in the mandibular
fossa, so these answers are not correct. Finally, the pterygoid fossa
(also known as pterygoid fovea) is a fossa found on the mandible itself;
it's not a place where the mandible could move to dislocate. For a better
understanding of this, see Netter Plate 10 and 11.
3. The correct answer is:
Maxillary
The maxillary artery is one of the terminal branches of the external
carotid artery which is closely related with the TMJ. It travels medial to
the neck of the condyle, so it would be the artery damaged in this
scenario. The buccal artery is a branch of the maxillary artery that
travels in the cheek. It supplies blood to the cheek mucosa and skin. The
external carotid artery is the source of the maxillary artery, but it is not
the artery lying medial to the neck of the mandibular condyle. The middle
meningeal artery is a branch of the maxillary artery which is deep to the
lateral pterygoid muscle. It supplies the calvaria and the dura
surrounding the brain. Finally, the superficial temporal artery is the other
terminal branch of the external carotid artery. It courses posterior and
lateral to the head of the mandible to supply the scalp of the lateral side
of the head and lateral face. See Netter Plate 35 for a picture of all of
these arteries and their interconnections.
4. The correct answer is:
mylohyoid
The submandibular triangle is a space bounded by the anterior and
posterior bellies of the digastric and the body of the mandible. It is found
superficial to the mylohyoid muscle. The submandibular triangle contains
the superficial submandibular gland, stylohyoid muscle, facial artery and
facial vein.
The paralingual space is a space found deep to the mylohyoid muscle,
which makes the mylohyoid the dividing line between these two distinct
spaces. It is bounded by the lateral tongue (including the hyoglossus,
styloglossus, and genioglossus muscles), hyoid bone, and oral mucosa.
It contains the deep portion of the submandibular gland, the
submandibular duct and the sublingual caruncle, lingual nerve and
submandibular ganglion, hypoglossal nerve, and sublingual gland and
fold.
5. The correct answer is:
temporalis
Temporalis is the one muscle responsible for retracting the mandible--it
pulls the mandible backwards. The lateral pterygoid protracts the
mandible, or pulls it forward. It is the one jaw muscle that allows for
opening the mouth. The masseter is a powerful chewing muscle that
elevates the mandible. The medial pterygoid also elevates the mandible;
it has a similar position and action to the masseter, but the ramus of the
mandible separates the two muscles. Mylohyoid elevates the hyoid bone
and the tongue and depresses the mandible.
6. The correct answer is:
condyle and articular disc
The TMJ joint is a synovial joint with two articular cavities. Each cavity is
responsible for a different movement at the joint. An articular disc sits
between the condylar process of the mandible on its inferior side and the
mandibular fossa and articular eminence of the temporal bone on the
superior side. This disc divides the joint into the two articular cavities,
with one cavity acting as a hinge component and the other cavity serving
as a gliding component. The lower part of the joint, between the condyle
and the articular disc, is the hinge component of the joint. When the joint
moves, this hinge component of the joint moves first, to initiate
mandibular opening. The upper part of the joint, between the articular
disc and the mandibular fossa and articular eminence of the temporal
bone, creates the gliding component. During joint movement, this gliding
cavity moves after the hinge component to terminate mandibular
opening.
7. The correct answer is:
Inferior alveolar
The inferior alveolar nerve is a branch of the mandibular division of the
trigeminal nerve (V3). It penetrates the mandibular foramen and is the
sensory nerve for the mandible and all mandibular teeth. This is the
nerve anesthetized by dentists working on the mandibular teeth. It is
anesthetized near the mandibular foramen, so sensory nerves from
branches distal to that point would be blocked. The lingual nerve is
another branch of V3--it transmits general sensation from the tongue.
The lingual nerve also receives the chorda tympani, a branch of the
facial nerve. The chorda tympani gives the lingual nerve preganglionic
parasympathetic fibers for the submandibular and sublingual glands, as
well as the taste fibers for the anterior 2/3 of the tongue. The buccal
nerve is a branch of V3 that transmits sensory information from the skin
of the cheek area and the oral mucosa of the cheek. Remember: The
buccal nerve is NOT the same as the buccal branch of the facial nerve,
which is a motor nerve innervating the buccinator and muscles of the
upper lip!!!
The mental nerve is a branch of V3 from the inferior alveolar nerve--it
provides sensory innervation to the skin of the chin and lower lip. The
nerve to mylohyoid is also a branch of V3--it innervates the mylohyoid
muscle and the anterior belly of the digastric. All of these branches of
the inferior alveolar nerve could end up being anesthetized as a result of
the dental work, but these nerves are not the dentist's main target!
8. The correct answer is:
Lateral pterygoid
The lateral pterygoid muscle protrudes the mandible--it pulls the
mandible forward to allow for depression of the chin (which is mostly
produced by gravity). None of the other muscles help with this function.
The anterior belly of the digastric and mylohyoid have similar functions:
they both help elevate the hyoid bone and depress the mandible. The
buccinator is a muscle in the cheek; it pulls the corner of mouth laterally
and presses the cheek against the teeth. Temporalis is important for
retracting and elevating the mandible.
9. The correct answer is:
mandible
paralysis of the muscles which elevate the
The masseter, medial pterygoid, and temporalis are all muscles that
elevate the mandible. These muscles are innervated by branches of V3,
the mandibular division of the trigeminal nerve. So, none of these
muscles would be denervated if the facial nerve was injured. The other
actions discussed all involve the muscles of facial expression, which are
innervated by the facial nerve (CN VII). The buccinator muscle is
innervated by the buccal branches of the facial nerve--this muscle pulls
the corner of mouth laterally and presses the cheek against the teeth.
The orbicularis oris is the muscle that allows for whistling or closing the
lips; this muscle is innervated by the buccal branches of the facial nerve.
10. The correct answer is:
otic ganglion
The lesser petrosal nerve is a branch of the glossopharyngeal nerve (CN
IX). The lesser petrosal nerve carries presynaptic parasympathetic fibers
to the otic ganglion. These fibers synapse in the otic ganglion, and the
postsynaptic fibers travel on the auriculotemporal nerve to innervate the
parotid gland. The geniculate ganglion is the sensory ganglion of the
facial nerve--it holds the cell bodies of the neurons that carry taste
sensations from the anterior 2/3 of the tongue. The submandibular
ganglion receives preganglionic parasympathetic fibers from the chorda
tympani; the postsynaptic fibers from the submandibular ganglion go to
the sublingual and submandibular glands. Finally, the ciliary ganglion
receives preganglionic parasympathetic fibers from the inferior division
of the oculomotor nerve. The postganglionic fibers from this ganglion
leave via short ciliary nerves and innervate sphincter pupillae and the
ciliary muscle of the eye. Also remember that sensory and sympathetic
fibers are passing through the ciliary ganglion and distributing on the
short ciliary nerves, but these fibers never synapse in that ganglion.
11. The correct answer is:
Premasseteric notch
The facial artery arises from the external carotid artery and winds around
the inferior border of the mandible deep to the platysma, immediately
anterior to the insertion of masseter muscle. This is the area of the
premasseteric notch. The notch lies anterior to the angle of the
mandible, so angle would not be a landmark to find the facial artery.
12. The correct answer is:
Mylohyoid
Mylohyoid is innervated by the nerve to mylohyoid, which is a branch of
the inferior alveolar nerve. The inferior alveolar nerve is a branch of the
mandibular division of the trigeminal nerve. Geniohyoid is a muscle that
spans from the mental spines of the mandible to the body of the hyoid
bone--it elevates the hyoid and depresses the mandible. It is innervated
by the ventral primary ramus of spinal nerve C1 via fibers carried by the
hypoglossal nerve. Hyoglossus is a tongue muscle; it is innervated by
the hypoglossal nerve (CN XII). Finally, stylohyoid is a muscle that
spans from the styloid process to the hyoid bone. It elevates and retracts
the hyoid, and it is innervated by the facial nerve.
13. The correct answer is:
inferior alveolar nerve
The inferior alveolar nerve provides sensory innervation to the
mandibular teeth. This nerve runs in the mandibular foramen, near the
roots of the teeth. So, it might be endangered when removing an
impacted tooth. The hypoglossal nerve travels lateral to the carotid
vessels and through the floor of the mouth. The glossopharyngeal nerve
consists of pharyngeal branches that provide sensory innervation to the
upper pharynx and lingual branches that sweep around the
stylopharyngeus muscle and continue to the base of the tongue. Finally,
the lingual nerve, which is from the mandibular division of the trigeminal
nerve, is found in the floor of the mouth. These three nerves are far from
the area of the impacted tooth, so they would not be endangered by the
dental procedure.
14. The correct answer is:
posterior part of temporalis
The fibers of the posterior part of temporalis retract the mandible; the
fibers from the anterior part of temporalis elevate the mandible. The
anterior and deep heads of the masseter muscle are both important for
elevating the mandible--remember, the masseter is the very powerful
chewing muscle!
15. The correct answer is:
buccal
The lateral pterygoid muscle has 2 heads: The superior head of the
muscle inserts into the disc and capsule of the temporomandibular joint
while the inferior head inserts into the neck of the mandible (the
pterygoid fovea). There are two nerves coming between the heads of the
lateral pterygoid muscle: the anterior deep temporal nerve and the
buccal nerve. See Netter Plate 42A for a picture of these nerves. The
masseteric nerve courses superior to the 2 heads of the lateral
pterygoid, not between the 2 heads. The lingual nerve travels inferior to
the two heads of the muscle. The inferior alveolar nerve also travels
inferior to the two heads of the lateral pterygoid before it enters the
mandibular foramen.
16. The correct answer is:
petrotympanic fissure
The chorda tympani exits the skull through the petrotympanic fissure.
The stylomastoid foramen is the space that the facial nerve travels
through to leave the skull--remember, the chorda tympani has already
separated away from the facial nerve by this point. Foramen spinosum is
a hole in the base of the skull that transmits the middle meningeal artery
and vein. Finally, foramen lacerum is a ragged foramen that is an artifact
of a dried skull. In life, it is closed by cartilage. Nothing passes directly
through foramen lacerum, although both greater and deep petrosal
nerve pass through some of the cartilage that fills it, in order to enter the
pterygoid canal at the anterior margin of foramen lacerum.
17.
The correct answer is:
Temporalis
Temporalis is the important muscle for retracting the mandible!
Buccinator is a muscle on the side of the face which pulls the corner of
mouth laterally and presses the cheek against the teeth. Both portions of
the lateral pterygoid protract the mandible and open the mandible.
(Remember: lateral pterygoid is the only muscle that opens the
mandible!) Finally, the medial pterygoid protracts and elevates the
mandible.
18. The correct answer is:
buccinator
The mandibular division of the trigeminal nerve (V3) is transmitted
through foramen ovale. Branches from this nerve innervate the muscles
of mastication, like temporalis and masseter. A branch from V3 also
innervates tensor tympani, which is a muscle that dampens the
vibrations of the tympanic membrane. Mylohyoid is innervated by a
branch of the inferior alveolar nerve which is also from V3--this muscle
elevates the hyoid bone and the tongue and depresses the mandible.
Buccinator is a muscle on the side of the cheek which is innervated by
the facial nerve (VII). This muscle, which pulls the corner of mouth
laterally and presses the cheek against the teeth, would still be
functional even after disrupting the mandibular division of the trigeminal
nerve.
19.
The correct answer is:
Superior head of the lateral pterygoid
The superior head of lateral pterygoid is sometimes called
sphenomeniscus due to its insertion into the disc of the
temporomandibular joint. Remember, the superior head of the lateral
pterygoid inserts into the disc of the TMJ, while the inferior head of the
lateral pterygoid inserts into the neck of the mandible (pterygoid fovea).
None of the other listed muscles insert into a joint like the superior head
of the lateral pterygoid.
20. The correct answer is:
lateral pterygoid muscle
Remember--the lateral pterygoid muscle is the one muscle of
mastication that is responsible for opening the jaw! It also draws the
mandible forward. The anterior part of the temporalis muscle elevates
the mandible, while the posterior part of temporalis retracts the
mandible. Masseter is a powerful chewing muscle that elevates the
mandible. The medial pterygoid muscle elevates the mandible and can
help to move the mandible forward. But, when the mouth is open, the
lateral pterygoid will be the most important muscle for drawing the
mandible forward.
21.
The correct answer is:
Skin of chin
The dentist would need to numb the inferior alveolar nerve, which is the
nerve that runs in the mandibular foramen and provides sensory
innervation to the teeth. The inferior alveolar nerve also gives off the
mental nerve, which is a sensory nerve innervating the skin of the chin.
So, if the inferior alveolar nerve was anesthetized, the mental nerve
would be anesthetized, too. Then, the patient would lose sensory
innervation to the skin of the chin.
The back of the tongue (posterior 1/3) receives sensory innervation from
the glossopharyngeal nerve. This nerve would not be exposed to the
anesthetic. The external ear is innervated by the auriculotemporal nerve,
which is not near the area of anesthesia. The maxillary incisor teeth are
innervated by the superior alveolar nerves, which are branches of the
maxillary division of the trigeminal nerve (V2). The skin of the upper lip is
also innervated by a branch of V2--the infraorbital nerve. These branches
of V2 would not be exposed to the anesthesia.
If too much anesthesic was injected or if the parotid fascia was pierced
by the needle, it would be possible for the anesthesic to diffuse through
the soft tissue and paralyze the facial nerve. A high dose of anesthesic
might also diffuse to paralyze the muscles of mastication.
22.
The correct answer is:
usually arises deep to the neck of the mandible
The middle meningeal artery is always found deep to the lateral
pterygoid muscle, so it is arising deep to the neck of the mandible. It
enters the skull by passing through the foramen spinosum, not through
foramen ovale. Remember--foramen ovale transmits the mandibular
branch of trigeminal. Although the middle meningeal artery appears to
pass through a fork in the auriculotemporal nerve, it does not pass
through a split in the trunk of V3. The middle meningeal artery is not a
branch of the second part of the maxillary artery--it is a very early branch
that separates from the maxillary artery almost immediately. It supplies
blood to the dura mater and the bones of the cranial vault, but it does not
supply the temporal lobe of the brain. The temporal lobe is supplied by
the middle cerebral artery.
23. The correct answer is:
Maxillary artery
The maxillary artery is one of the terminal branches of the external
carotid artery. It enters the infratemporal fossa and is the major source
of blood for that region. The internal carotid artery is the primary blood
supply to the brain. The lingual artery is another branch of the external
carotid artery--it supplies blood to the tongue and the floor of the mouth.
The posterior auricular is a branch of the external carotid artery that
supplies the external ear, scalp and the deeper structures posterior to
the ear. The superficial temporal artery is the other terminal branch of
the external carotid artery -- it supplies blood to the scalp of the lateral
side of the head and the lateral face.
24. The correct answer is:
lateral pterygoid
The inferior head of the lateral pterygoid inserts into the neck of the
mandible, while the superior head of the lateral pterygoid inserts directly
into the capsule and articular disk of the temporomandibular joint. So,
this muscle would be affected by arthritis of the joint. This muscle is the
only one that opens the mandible, so this movement might be weakened
if there was inflammation at the TMJ.
Temporalis elevates and retracts the mandible; it inserts on the coronoid
process of the mandible and the anterior surface of the ramus of the
mandible. The medial pterygoid muscle protracts and elevates the
mandible; it inserts on the medial surface of the ramus and angle of the
mandible. Finally, the masseter is the muscle that powerfully elevates
the mandible--it inserts on the lower half of the ramus of the mandible.
None of these other muscles are inserting into the TMJ, so they would
not be impaired quite as much as the lateral pterygoid.
25. The correct answer is:
Inferior alveolar
The inferior alveolar nerve is a branch of the mandibular division of the
trigeminal nerve (V3). It travels through the mandibular foramen and
provides sensory innervation to the mandibular teeth. The lingual nerve
is another branch of V3--it travels in the floor of the mouth and provides
sensory innervation to the anterior 2/3 of the tongue and the floor of the
mouth. The nerve to mylohyoid is a motor branch of V3--it provides motor
innervation to mylohyoid and the anterior belly of the digastric. Finally,
the buccal nerve is a sensory branch of V3 that supplies the cheek and
oral mucosa.
26. The correct answer is:
action
A completely flat surface for its gliding
The TMJ joint is a synovial joint with two articular cavities. Each cavity is
responsible for a different movement at the joint. The lower part of the
joint is the hinge component of the joint. When the joint moves, this
hinge component of the joint initiates mandibular opening. The upper
part of the joint is the gliding component. During joint movement, this
gliding cavity moves to terminate mandibular opening. The gliding cavity
is the space between the articular disc and the mandibular fossa and
articular eminence of the temporal bone--it's not a completely flat
surface.
There are extracapsular ligaments around the TMJ joint capsule, but
these ligaments are on the lateral side only. The lateral ligament
reinforces the lateral part of the capsule, while other ligaments (the
stylomandibular and sphenomandibular) only have a minor role in
stabilizing the joint capsule. There is also an articular disc dividing the
two components of the joint, and the two cavities are different shapes.
See Netter Plate 11 for a picture of all of these structures.
27. The correct answer is:
Lateral pterygoids
The TMJ may dislocate anteriorly due to excessive contraction of the
lateral pterygoids (for example, during excessive opening of the mouth).
This could happen if someone yawned too much or took a large bite of
food. Posterior dislocations of the TMJ are rare due to resistance from
the postglenoid tubercle and the strong lateral ligaments.
The buccinator is an important muscle for mastication because it keeps
the cheek taut, so the cheek can press against the molars. However, it is
a facial muscle innervated by the facial nerve, and it is not active at the
TMJ. The medial pterygoid, masseter and temporalis produce motion at
the TMJ, but contracting these muscles does not cause the joint to
dislocate.
28. The correct answer is:
Lingual artery
Remember--all over the body, the vasculature is the number one target
of sympathetic nerves. Sympathetic nerves help to constrict the
vasculature, and they are found covering arteries in periarterial
plexuses. In the head, sympathetics travel to targets on vessels. So, you
know that the sympathetic nerves are coming to the tongue on an artery-now, you just need to determine what artery goes to the tongue. And
that artery is the lingual artery.
The lingual artery is the second branch off the anterior side of the
external carotid artery. It travels in the floor of the mouth and supplies
blood to the tongue, suprahyoid muscles, and the palatine tonsil. This is
the artery going to the targeted area, so that's the answer you're looking
for. The maxillary artery is one of the 2 terminal branches of the external
carotid artery. It supplies blood to the deep face and infratemporal fossa.
It is not going to the tongue.
As far as the nerves go... The lingual nerve is a branch of V3, the
mandibular division of the trigeminal nerve. It supplies general sensation
(touch and temperature) to the anterior 2/3 of the tongue. (Taste
sensation for the anterior 2/3 of the tongue arrives at the tongue by way
of the lingual nerve, but the original fibers for taste came from the chorda
tympani, a branch of CN VII.) The hypoglossal nerve (CN XII) provides
motor innervation to the muscles of the tongue. The glossopharyngeal
nerve (CN IX) provides taste sensation and general sensation to the
posterior 1/3 of the tongue.
29.
The correct answer is:
Mucous membrane only
The submandibular duct is found deep to the mucous membrane of the
mouth, but superficial to the muscles of the tongue and the muscles on
the floor of the mouth. So, genioglossus, mylohyoid, and hyoglossus are
deep to the submandibular duct. See Netter Plate 56B for a picture of
these relationships.
30. The correct answer is:
tongue
General sensation to the anterior 2/3 of the
The lingual nerve is a branch of V3, the mandibular division of the
trigeminal nerve. It transmits general sensation from the anterior 2/3 of
the tongue. Damaging this nerve anywhere along its course would cause
someone to lose general sensation to the anterior 2/3 of the tongue. The
chorda tympani is a branch of VII--it carries taste fibers to the anterior
2/3 of the tongue and presynaptic parasympathetic fibers to the
submandibular ganglion. The fibers from the chorda tympani join the
lingual nerve as they travel to the submandibular ganglion and the
anterior tongue. However, if the lingual nerve was damaged before the
chorda tympani had joined it, the chorda tympani fibers would still be
intact. So, there would still be taste innervation to the anterior 2/3 of the
tongue and the submandibular gland would still secrete. If the lingual
nerve was disrupted after the chorda tympani had already joined it, there
would be no secretomotor innervation to the submandibular and
sublingual glands, and there would be no taste or general sensation to
the anterior 2/3 of the tongue.
As for the posterior 1/3 of the tongue, it receives taste and general
sensation from the glossopharyngeal nerve (CN IX).
31.
The correct answer is:
oral vestibule
The oral vestibule is the space in the mouth lying between the lips and
the teeth. See Netter Plate 45 for an illustration of the mouth--although
the vestibule isn't labeled, you can get some idea of where it lies. The
nasal cavities are spaces that connect the nasopharynx with the external
environment. The roof of the nasal cavity is made of the cribriform plate
of the ethmoid bone. The floor of the nasal cavity is made of the hard
palate. The medial wall is made by the nasal septum, and the lateral wall
is the place where the inferior, superior, and middle conchae project into
the nasal cavity.
The oropharynx is the middle part of the pharynx, found behind the
mouth. It communicates anteriorly with oral cavity through the
palatoglossal arch, superiorly with the nasopharynx through the posterior
margin of soft palate, and inferiorly with the laryngopharynx at the
superior margin of epiglottis. The oropharynx contains the palatine tonsil,
which is located between the palatoglossal arch and the
palatopharyngeal arch.
The paralingual space is a space inside the floor of the mouth. It is
bounded by the mylohyoid muscle, the lateral tongue, the hyoid bone,
and the oral mucosa. The paralingual space contains the deep portion of
the submandibular gland, the lingual nerve and submandibular ganglia,
the sublingual gland and fold, and the hypoglossal nerve.
Finally, the submandibular space is a space defined by the body of the
mandible and the anterior and posterior digastric muscles. It contains the
superficial submandibular gland, mylohyoid and stylohyoid muscles, the
facial artery, and the facial vein.
32. The correct answer is:
Dorsal lingual artery
The dorsal lingual artery runs on the superficial surface of the tongue--it
is a branch of the lingual artery that delivers blood to the posterior
superficial tongue. So, this artery must be the source of the hemorrhage.
The deep lingual artery and sublingual artery are two terminal branches
of the lingual artery. These branches run in the floor of the mouth
(sublingual) and the deep surface of the tongue (deep lingual). See
Netter Plate 53 for a picture. The facial artery is a branch of the external
carotid artery that courses across the face. The tonsillar artery is a
branch of the facial artery that supplies blood to the palatine tonsil.
33. The correct answer is:
Styloglossus
Styloglossus retracts and elevates the tongue. Genioglossus is a large,
fan shaped muscle with many actions: its inferior fibers protrude the
tongue, its middle fibers depress the tongue, and its superior fibers draw
the tip back and down. Hyoglossus retracts and depresses the tongue.
All of these muscles are innervated by the hypoglossal nerve (CN XII).
Stylohyoid elevates and retracts the hyoid bone. It is innervated by the
facial nerve (CN VII). Stylopharyngeus elevates the larynx--it is
innervated by the glossopharyngeal nerve (IX).
34. The correct answer is:
Palatoglossus muscle
All of the tongue muscles are innervated by the hypoglossal nerve. So,
hyoglossus, genioglossus, and styloglossus are all innervated by the
hypoglossal nerve. Although palatoglossus sounds like a tongue muscle,
it is a palatal muscle, innervated by the vagus nerve. (Palatoglossus is
the only "glossus" muscle that is not innervated by the hypoglossal
nerve.)
35. The correct answer is:
Lingual artery
The paralingual space is a space inside the floor of the mouth. It is
bounded by the mylohyoid muscle, the lateral tongue, the hyoid bone,
and the oral mucosa. The paralingual space contains the deep portion of
the submandibular gland, the lingual nerve and submandibular ganglion,
the sublingual gland and fold, and the hypoglossal nerve. The lingual
artery is not in the paralingual space.
36. The correct answer is:
facial nerve
Taste fibers to the anterior 2/3 of the tongue come from the chorda
tympani--a branch of the facial nerve. So, if the patient has lost taste
sensation to the anterior 2/3 of the tongue, the patient might have a
lesion of the facial nerve. The glossopharyngeal nerve (CN IX) carries
taste and general sensory fibers to the posterior 1/3 of the tongue. The
hypoglossal nerve (CN XII) gives motor innervation to all the muscles of
the tongue (ie, all the muscles that end in glossus except for
palatoglossus, which is a palate muscle innervated by the vagus). The
trigeminal nerve supplies general sensory fibers to the anterior 2/3 of the
tongue via the lingual nerve, a branch of V3. Remember, the chorda
tympani fibers jump on the lingual nerve to reach the tongue, but the
chorda tympani fibers originate from the facial nerve! Finally, the vagus
nerve supplies general and taste sensation to a very small part of the
posterior tongue, right next to the epiglottis.
37. The correct answer is:
preganglionic parasympathetics
The chorda tympani contains preganglionic parasympathetic nerves that
go to the submandibular ganglion. These preganglionic
parasympathetics synapse in the submandibular ganglion and then
provide secretomotor innervation to the submandibular and sublingual
glands. The chorda tympani also contains taste fibers to the anterior 2/3
of the tongue, but not to the posterior 1/3.
38. The correct answer is:
geniculate ganglion
The geniculate ganglion is the sensory ganglion of the facial nerve--it
holds the cell bodies of the neurons that carry taste sensations from the
anterior 2/3 of the tongue. These fibers then travel on the chorda
tympani, which carries the fibers to the lingual nerve. The chorda
tympani fibers then jump on the lingual nerve so they can reach the
tongue and provide taste sensation to the anterior 2/3. The otic ganglion
is the ganglion where parasympathetic fibers synapse before innervating
the parotid gland. The lesser petrosal nerve is a branch of the
glossopharyngeal nerve (CN IX) that carries presynaptic
parasympathetic fibers to the otic ganglion. These fibers synapse in the
otic ganglion, and the postsynaptic fibers travel on the auriculotemporal
nerve to the parotid gland.
The pterygopalatine ganglion is the ganglion that enables secretomotor
innervation to the mucous glands of the palate, nasal cavity, and lacrimal
gland. Preganglionic fibers arrive at this ganglion from the greater
petrosal nerve of the facial nerve. The submandibular ganglion receives
preganglionic parasympathetic fibers from the chorda tympani; the
postsynaptic fibers from the submandibular ganglion go to provide
secretomotor innervation to the sublingual and submandibular glands.
Finally, the trigeminal ganglia (also called the semilunar ganglia) is a
sensory ganglion equivalent in histological structure and function to a
dorsal root ganglion. The cell bodies of the afferent fibers of the
trigeminal nerve reside in this ganglion.
39. The correct answer is:
the opening of the parotid duct
The oral vestibule is the space in the mouth lying between the lips and
the teeth. See Netter Plate 45 for an illustration of the mouth and
vestibule--although the vestibule isn't labeled, you can get some idea of
where it lies. You can also see that the parotid duct is opening into this
space . The parotid duct drains the parotid gland; it crosses the
masseter to enter the cheek and drain into the oral cavity. The parotid
duct drains into the cheek near the upper 2nd molar tooth.
The tongue is not in the vestibule--it's behind the teeth. The
submandibular duct opens into the area under the tongue, near the
tongue's frenulum. The sublingual fold is also underneath the tongue;
this is the fold that contains the openings for the ducts of the sublingual
gland to drain into the mouth. The uvula is the "punching bag" hanging
from the soft palate at the back of the oral cavity.
40. The correct answer is:
genioglossus
Genioglossus is a large, fan shaped muscle with many actions: its
inferior fibers protrude the tongue, its middle fibers depress the tongue,
and its superior fibers draw the tip back and down. So, since the tongue
is being protruded, the inferior fibers of genioglossus must be
contracting. Styloglossus retracts and elevates the tongue. Hyoglossus
depresses the sides of tongue and retracts the tongue. The superior
longitudinal and verticalis muscles are intrinsic muscles of the tongue.
They help shape the tongue for speech and chewing. All of these
muscles are innervated by the hypoglossal nerve!
41. The correct answer is:
mylohyoid
The mylohyoid muscle elevates the hyoid bone and the tongue and
depresses the mandible. It is a muscle in the floor of the mouth that
helps elevate the floor of the mouth, so this is the correct answer. The
genioglossus is a large, fan shaped tongue muscle that protrudes
tongue with its inferior fibers and depresses the tongue with its middle
fibers. Geniohyoid is a small muscle in the floor of the mouth that
elevates the hyoid and depresses the mandible. Hyoglossus is a tongue
muscle that depresses the sides of the tongue and retracts the tongue.
Finally, palatoglossus is a palate muscle, innervated by the vagus nerve.
It elevates and retracts the tongue.
42. The correct answer is:
submandibular ganglion
The submandibular ganglion contains the cell bodies of the
postganglionic parasympathetic neurons that innervate the sublingual
and submandibular gland. Preganglionic parasympathetic fibers arrived
at the submandibular ganglion via the chorda tympani. These neurons
then synapsed with the cell bodies in the submandibular ganglion, and
the postganglionic fibers traveled out to provide secretomotor
innervation to the sublingual and submandibular glands.
The ciliary ganglion receives preganglionic parasympathetic fibers from
the inferior division of the oculomotor nerve. The postganglionic fibers
from this ganglion leave via short ciliary nerves and innervate sphincter
pupillae and the ciliary muscle of the eye. Also remember that sensory
and sympathetic fibers are passing through the ciliary ganglion and
distributing on the short ciliary nerves, but these fibers never synapse in
that ganglion. The otic ganglion is the ganglion where parasympathetic
fibers synapse before innervating the parotid gland. The lesser petrosal
nerve is a branch of the glossopharyngeal nerve (CN IX) that carries
presynaptic parasympathetic fibers to the otic ganglion. These fibers
synapse in the otic ganglion, and the postsynaptic fibers travel on the
auriculotemporal nerve to the parotid gland.
The superior cervical ganglia is at the level of the C1 and C2 vertebrae-it is the highest ganglia in the sympathetic chain. Sympathetic nerves
from this ganglia go to form the internal carotid sympathetic plexus along
the internal carotid artery. Finally, the trigeminal ganglia (also called the
semilunar ganglia) a sensory ganglion equivalent in histological structure
and function to a dorsal root ganglion. The cell bodies of the afferent
fibers of the trigeminal nerve reside in this ganglion.
43. The correct answer is:
Lingual
The lingual nerve is found in the floor of the mouth--it wraps around the
submandibular duct. So that nerve might be injured as you try to remove
the stone from the submandibular duct. The lingual nerve contains
general sensory fibers for the anterior 2/3 of the tongue, and fibers from
the chorda tympani that provide taste to the anterior 2/3 of the tongue.
All of these sensory components might be lost if the lingual nerve was
damaged.
At the point where the lingual nerve is wrapping around the
submandibular gland, the fibers from chorda tympani have already
joined the lingual nerve.This means that fibers from chorda tympani
might be damaged, but the chorda tympani itself is not near the
submandibular duct. The glossopharyngeal nerve provides sensory and
taste innervation to the posterior 1/3 of the tongue and sensory
innervation to the pharynx--it is not associated with the submandbular
duct. The hypoglossal nerve is in the sublingual space, just like the
submandibular duct. However, it is deeper in the sublingual space and
does not wrap around the duct. Remember--the lingual nerve is a much
more superficial structure in the sublingual space. Finally, the internal
branch of the superior laryngeal nerve crosses the thyrohyoid membrane
to provide sensory innervation to the mucosa of the pharynx, superior to
the vocal folds.
44. The correct answer is:
facial artery
The submandibular triangle is formed by the lower border of the
mandible and the anterior and posterior bellies of the digastric muscle.
The facial artery and facial vein course through this triangle. The facial
artery lies deep to the superficial part of the submandibular gland and
wraps around the mandible. The facial vein is superficial to the gland-see Netter Plate 27 for a picture. The external jugular vein is a
superficial vein on the lateral side of the neck. The maxillary artery is a
branch of the external carotid artery that is the main source of blood to
the infratemporal fossa. The retromandibular vein is a vein that passes
through the parotid gland, along with the facial artery and facial nerve.
Finally, the superior thyroid artery is a branch of the external carotid that
supplies blood to the superior pole of the thyroid.
45. The correct answer is:
Superficial lobe of the submandibular gland
The paralingual space is found in the floor of the mouth, deep to the
mylohyoid muscle. The space is bounded by the lateral tongue, the
hyoid bone, and the oral mucosa. Remember--the submandibular gland
has a deep and superficial portion. The deep portion of the
submandibular gland is found deep to the mylohyoid muscle, while the
superficial portion of the submandibular gland is found superficial to the
mylohyoid muscle. So, the deep portion of the submandibular gland is in
the paralingual space, while the superficial portion of the submandibular
gland is not. See Netter Plate 55 for a picture of this.
The paralingual space also contains the submandibular duct and
sublingual caruncle, the lingual nerve and submandibular ganglion, the
hypoglossal nerve, and the sublingual gland and fold.