LECTURE: Muscles of Mastication Flashcards
(112 cards)
1
Q
The primary muscles of mastication
A
temporalis, masseter and pterygoids
2
Q
the boundaries of the temporal fossa
A
- Posteriorly and superiorly by the temporal lines.
- Anteriorly by the frontal and zygomatic bones
- Laterally by the zygomatic arch.
- Inferiorly by the infratemporal crest.
3
Q
What makes up the floor of the temporal fossa?
A
lateral skull
4
Q
What makes up the roof of the temporal fossa?
A
temporal fascia
5
Q
The temporal fascia covers the ______ muscle
A
temporalis
6
Q
Action of temporal fascia during chewing
A
pulling up on the zygomatic arch
7
Q
Action of the masseter during chewing
A
inferior pull by masseter
8
Q
What is the infratemporal fossa?
A
an irregularly shaped space deep and inferior to the zygomatic arch and deep to the ramus of the mandible
9
Q
What does the infratemporal fossa communicate with?
A
the temporal fossa under the zygomatic arch
10
Q
The boundaries of the infratemporal fossa
A
- Laterally: the ramus of the mandible.
- Medially: the lateral pterygoid plate.
- Anteriorly: the posterior aspect of the maxilla.
- Posteriorly: the mastoid and styloid processes of temporal bone.
11
Q
The infratemporal fossa opens into the
A
pterygomaxillary fissure
12
Q
The pterygomaxillary fissure leads to the
A
pterygopalatine fossa
13
Q
In the medial wall of the pterygopalatine fossa is an opening called the
A
sphenopalatine foramen
14
Q
The sphenopalatine foramen leads to the
A
nasal cavity
15
Q
O/I/A/N of temporalis muscle
A
- O: temporal fossa
- I: coronoid process and anterior ramus of mandible
- A: elevate mandible with chewing, the posterior part of muscle retract mandible
- N: mandibular division of V3 (via deep temporal nerves)
16
Q
O/I/A/N of masseter muscle
A
- O: zygomatic arch (superficial portion above the arch, the posterior portion of muscle at the posterior part of the arch)
- I: angle and lateral aspect of ramus of mandible
- A: elevate mandible with chewing, the posterior part of muscle protrude the mandible
- N: mandibular division of V3 (via deep temporal nerves)
17
Q
Which muscle of mastication has a superior and inferior head?
A
lateral pterygoid
18
Q
O/I/A/N of the inferior head of lateral pterygoid
A
- O: lateral surface of the lateral pterygoid plate
- I: neck of mandible, articular disc and capsule of TMJ (same as superior head)
-
A: two actions (same as superior head)
- bilaterally: protraction of condyle
- unilaterally: moves mandible laterally
- N: lateral pterygoid branches of V3
19
Q
O/I/A/N of the superior head of lateral pterygoid
A
- O: infratemporal surface of greater wing of sphenoid
- I: neck of mandible, articular disc and capsule of TMJ (same as inferior head)
-
A: two actions (same as inferior head)
- bilaterally: protraction of condyle
- unilaterally: moves mandible laterally
- N: lateral pterygoid branches of V3
20
Q
O/I/A/N of the superficial head of medial pterygoid
A
- O: maxillary bone
- I: medial aspect of the angle of the mandible (same as deep head)
-
A: two actions (same as deep head)
- bilaterally: elevates and protrudes the mandible (working with masseter)
- unilaterally: moves the mandible contralaterally (grinding movements)
- N: V3
21
Q
O/I/A/N of the deep head of medial pterygoid
A
- O: medial surface of lateral pterygoid plate
- I: medial aspect of the angle of the mandible (same as superficial head)
-
A: two actions (same as superficial head)
- bilaterally: elevates and protrudes the mandible (working with masseter)
- unilaterally: moves the mandible contralaterally (grinding movements)
- N: medial pterygoid branches of V3
22
Q
With damage to the lateral pterygoid on one side, the mandible will be …
A
deviated to the side that is damaged
23
Q
With a subcondylar fracture on the left, only the right lateral pterygoid is functional and will pull the mandible to the …
A
left (contralateral)
24
Q
The ____ is a hinge-like synovial joint.
A
temporomandibular joint (TMJ)
25
The articular surfaces involved are
1. condyle of the mandible
2. articular tubercle of the temporal bone
3. mandibular fossa
26
The TMJ is surrounded by a
capsule
27
What divides the joint cavity into a superior and inferior joint space of the TMJ?
an articular disc
28
The TMJ comprises what 2 types of synovial joints?
hinge and sliding
29
Structural Components of TMJ
1. Squamous portion of the temporal bone
2. Articular disc
3. Condyle of the mandible
4. TMJ compartments
5. capsule
6. superior and inferior lamina
30
Which structural component of the TMJ is responsible for providing an important articular surface that includes the articular eminence and glenoid fossa?
squamous portion of the temporal bone
31
Which structural component of the TMJ is biconcave and made of dense fibrous connected tissue?
articular disc
32
Which structural component of the TMJ is located between squamous portion of temporal bone and the condyle?
articular disc
33
What part of the articular disc is avascular and vascular?
central part is avascular
periphery is vascular
34
What anchors the articular disc to the condyle?
strong medial and lateral collateral ligaments
35
Which structural component of the TMJ articulates with the articular disc?
condyle
36
The articular surface of the condyle of the mandible is _____________ instead of hyaline cartilage.
avascular fibrous connective tissue
37
The TMJ superior and inferior compartments are what type of joints?
synovial joints
38
Which structural component of the TMJ encloses the articular surface of the temporal bone and the condyle?
capsule
39
Which structural component of the TMJ is strengthened medially and laterally by the collateral ligaments?
articular disc and the capsule
40
Which structural component of the TMJ anchor the posterior aspect of the disc to the temporal bone and condylar neck?
superior and inferior lamina
41
Which structural component of the TMJ serve as the borders for the retrodiscal pad?
superior and inferior lamina
42
What structural component of the TMJ is the highly vascular and neural part of the TMJ?
retrodiscal pad
43
Which TMJ ligament provide strong attachment for disc (to condyle)?
medial and lateral collateral ligaments
44
The medial and lateral collateral ligaments are made of collagenous connective tissue which prevents them …
from stretching
45
Which TMJ ligament prevents lateral and posterior displacement of the condyle?
lateral temporomandibular ligament
46
Which TMJ ligament is the only ligament that gives direct support to the TMJ capsule?
the lateral temporomandibular ligament
47
Which TMJ ligament helps limit anterior protrusion of the mandible?
stylomandibular ligament
48
Which TMJ ligament extends from the styloid process to the posterior margin of the angle of the mandible?
stylomandibular ligament
49
Which TMJ ligament extends from the spine of the sphenoid to the lingula of the mandible?
sphenomandibular ligament
50
Which TMJ ligament act as a pivot point on the mandible by maintaining the same amount of tension during both opening and closing of the mouth?
sphenomandibular ligament
51
What muscle(s) is responsible for elevation (closing)?
Temporalis, masseter and medial pterygoid
52
What muscle(s) is responsible for depression (opening)?
Lateral pterygoid and suprahyoid muscles
53
What muscle(s) is responsible for protrusion (forward)?
Lateral pterygoid, masseter and medial pterygoid
54
What muscle(s) is responsible for retrusion (retract)?
Temporalis (posterior part)
55
What muscle(s) is responsible for lateral movements?
Pterygoids, temporalis and masseter
56
Describe the process of opening the TMJ
1. inferior head of lateral pterygoid initiates opening
2. rotation of condyle in lower TMJ compartment and continues until the upper and lower teeth are 20 mm apart
3. As mandible depresses, the collateral ligaments are tightened
4. For additional opening, requires translational movement
57
What is translational movement of the TMJ?
this occurs in the upper TMJ compartment and accounts for most of the opening. The articular disc and condyle complex slides inferiorly and anteriorly on the articular eminence, opening the mouth an additional 30mm on average.
58
How far apart (on average) are the upper and lower incisors at the end of initial opening?
20 mm
59
The typical range of TMJ movement: opening
50 mm
60
The typical range of TMJ movement: protrusion
10 mm
61
The typical range of TMJ movement: excursion
10 mm
62
Mandibular dislocation occurs when
the condyle moves anterior to the articular eminence, locking the mouth in the opened position
63
This allows palpation of the glenoid fossa posterior to the condyle
mandibular dislocation
64
The external carotid artery will travel up the neck, just posterior to the mandibular ramus, before bifurcating into its two terminal branches called
the maxillary artery and superficial temporal artery
65
The __________ will travel anterior to the ear and then onto the side of the head to deliver blood to the temporal region
superficial temporal artery
66
The maxillary artery will course through the \_\_\_\_\_\_\_\_\_\_, providing numerous branches along the way
infratemporal fossa
67
The maxillary artery will course from posterior to anterior through the infratemporal fossa before giving rise to how many terminal branches?
four
68
The maxillary artery will give rise to which branches? (6)
1. inferior alveolar artery
2. deep temporal arteries
3. masseteric artery
4. buccal artery
5. pterygoid branches
6. middle meningeal artery
69
The inferior alveolar artery goes to the
lower teeth
70
The deep temporal arteries goes to the
temporalis
71
The masseteric artery goes to the
masseter
72
The buccal artery goes to the
cheek
73
The pterygoid branches goes to the
medial and lateral pterygoids
74
The middle meningeal artery goes to the
meninges
75
76
All of these arteries stem from what artery?
77
What artery supplies blood to the chin and lower lip?
mental artery
78
The mental artery is a branch off which artery?
the inferior alveolar
79
The middle meningeal artery is a deep branch of the maxillary artery that travels up through the floor of the skull through which opening?
foramen spinosum
80
After the main branches, the maxillary artery will give rise to 4 terminal branches called …
1. infraorbital artery
2. posterior superior alveolar artery
3. descending palatine artery
4. sphenopalatine artery
81
82
The infraorbital artery travels in the floor of the orbit before emerging from what opening?
infraorbital foramen
83
While passing through the floor of the orbit, the infraorbital artery give rise to what arteries?
middle and anterior superior alveolar arteries
84
The middle and anterior superior alveolar arteries supply blood to …
the upper teeth
85
The posterior superior alveolar artery travels through an opening in the maxilla to the
upper teeth
86
The descending palatine artery travels through the ______ onto the palate (roof of oral cavity).
palatine canal
87
The sphenopalatine artery travels through the __________ into the pterygopalatine fossa and through the sphenopalatine foramen to get to the nasal cavity.
pterygomaxillary fissure
88
The mandibular division of the trigeminal nerve (V3) is a mixed nerve with \_\_\_\_\_\_\_\_\_\_\_\_\_\_.
sensory and motor function
89
The mandibular division of the trigeminal nerve (V3) passes through which opening to enter the infratemporal fossa?
foramen ovale
90
Which nerves are the sensory components of V3? (4)
1. inferior alveolar nerve
2. lingual nerve
3. buccal nerve
4. auriculotemporal nerve
91
Which nerves are the motor components of V3? (4)
1. deep temporal nerves
2. masseteric nerve
3. medial and lateral pterygoid nerves
4. nerve to mylohyoid
92
Which nerve sends sensation from the lower teeth?
Inferior alveolar nerve
93
Which nerve sends sensation from the chin and lower lip?
mental nerve (from the inferior alveolar nerve)
94
Which nerve sends sensation from anterior ⅔ of tongue on the same side?
lingual nerve
95
Which nerve sends sensation from the skin and mucosa of the cheek?
buccal nerve
96
Which nerve sends sensation from the skin in front of ear and side of head, as well as from TMJ?
auriculotemporal nerve
97
Which nerve carries motor innervation to the temporalis?
deep temporal nerves
98
Which nerve carries motor innervation to the masseter?
masseteric nerve
99
Which nerve carries motor innervation to the pterygoids?
medial and lateral pterygoid nerves
100
Which nerve carries motor innervation to the mylohyoid and the anterior belly of digastric?
nerve to mylohyoid
101
The chorda tympani nerve is a component of which nerve?
facial nerve (CN VII)
102
The chorda tympani nerve joins the lingual nerve in what location?
infratemporal fossa
103
What nerve carries the taste from the anterior ⅔ of the tongue (on the same side)?
chorda tympani nerve
104
The chorda tympani nerve will also deliver parasympathetics to what?
the sublingual and submandibular salivary glands
105
The __________ is the parasympathetic ganglion serving the glands.
submandibular ganglion
106
What is the name of the ganglion that contains the postsynaptic parasympathetic neurons that innervate the submandibular and sublingual salivary glands?
Submandibular ganglion
107
108
109
What is the name of the venous plexus in the infratemporal fossa, and where does it drain?
The pterygoid plexus drains venous blood from structures of the infratemporal fossa and empties into the retromandibular vein.
110
Venous blood in the infratemporal fossa is drained by the
pterygoid plexus
111
The blood from the pterygoid plexus enters 1-2 maxillary veins, which drain into the
retromandibular vein
112
The retromandibular vein then drains into the
internal jugular vein
