Infratemporal Fossa-Sievert Flashcards
(121 cards)
1
Q
Which parts of the trigeminal nerve carry motor branches?
A
only V3…this has sensory & motor. The rest only have sensory branches.
2
Q
What type of a joint is the TMJ? It is prone to what?
A
TMJ is multiaxial
it is prone to dislocation
3
Q
What are the important muscles that are found in the infra temporal fossa?
A
muscles of mastication
4
Q
Where is the infra temporal fossa located?
A
deep to the mandible
inferior to the zygomatic arch
5
Q
What are the following boundaries of the infra temporal fossa?
A
Anterior Border: maxillary bone
Posterior Border: Temporal Bone
Medial Border: Lateral Pterygoid plate off the sphenoid bone
Lateral Border: ramus of mandible
Inferiorly: open, sorta contained by medial pterygoid
6
Q
What makes up the temporal region?
A
the temporal area + infra temporal fossa
7
Q
What is found in the temporal area?
A
the temporalis muscle & its overlying CT
8
Q
T/F The styloid process & mastoid process that are found on the head are a part of the temporal bone.
A
True.
9
Q
If you remove the zygomatic arch & mandible…which structures are visible in the infra temporal fossa region?
A
lateral pterygoid plate
infratemporal surface of the maxilla
pterygomaxillary fissure
10
Q
What is the pterygomaxillary fissure? What does it lead to? What else follows it?
A
This is sort of a crack that is found b/w the lateral pterygoid plate & the maxilla. It leads to the pterygopalatine fossa. A blood supply branches & follows this pathway as well.
11
Q
Which hole does the facial nerve exit from? What is the nerve mainly composed of at this point?
A
Exits via the stylomastoid foramen.
Mainly composed of motor branches at this point.
12
Q
What exits out of the foramen ovale?
A
V3 out of the cranial cavity into the infra temporal fossa
13
Q
What goes thru the foramen spinosum?
A
the middle meningeal artery goes from the infra temporal fossa into the cranial cavity. Opposite direction of V3.
14
Q
What’s the significance of the mandibular fossa?
A
this is the depression of the temporal bone where the condylar process of the mandible articulates with the temporal bone.
15
Q
What is the mandibular notch?
A
this is a little swoop of the bone b/w the coronoid process & the condylar process of the mandible.
16
Q
What is the mandibular foramen?
A
this is important! This is an entrance point for the nerves & blood vessels that supply the mandible & the teeth.
17
Q
Describe the TMJ.
A
the temporomandibular joint
this is made of 2 joint cavities (superior & inferior) & one articular disc
has a strong ligamentous capsule that contains it
18
Q
Which bones are involved in the TMJ?
A
the condylar process of the mandible
the mandibular fossa w/ the articular tubercle
19
Q
What is the most notable muscle involved in the TMJ? What does it attach to?
A
the lateral pterygoid muscle
one belly attaches to the condylar process of the mandible
the other belly attaches to the articular disc of the TMJ
20
Q
What family of muscles is the lateral pterygoid muscle a part of? What is its action on the TMJ?
A
mastication muscles!
It pulls the articular disc & the condylar process anteriorly
21
Q
Describe what happens to the TMJ when you open your mouth wide?
A
the lateral pterygoid muscle helps with this
the condyle rides anteriorly & pushes into the articular tubercle
**this is protraction
22
Q
What tragic thing happens when you open your mouth too wide?
A
the condylar process pushes too far anteriorly & rolls off the articular tubercle & gets stuck in an in b/w space.
Then all of the muscles of mastication are contracted & don’t allow you to push your jaw back to a resting position.
Requires muscle relaxants to get it back.
23
Q
What’s the deal with elevation & depression of the TMJ? Which joint cavity does this involve?
A
this involves hinge movements
this happens in the lower joint cavity
24
Q
What’s the deal with protraction & retraction of the TMJ? Which joint cavity does this involve?
A
this involves gliding movements
this happens in the upper joint cavity
**this of course involves the condylar process hitting the articular tubercle
25
How does a side to side grinding motion occur @ the TMJ?
the involves protraction of one side of the jaw while there is retraction of the other side of the jaw
26
What are the 2 important ligaments near the TMJ? (excluding the ligamentous capsule around the TMJ)
the sphenomandibular ligament
| the stylomandibular ligament
27
What is a fun fact about the actions of the sphenomandibular & stylomandibular ligaments on the TMJ?
they tighten up when you open your mouth & force the condylar process of the mandible to ride anteriorly if you open your mouth any further.
28
Wanna know something awesome about the TMJ? It has a high range of motion! What's something less awesome that is necessarily associated w/ this attribute?
sadly, it is highly susceptible to dislocation.
29
T/F The TMJ is a synovial joint.
True.
30
What covers the articular surfaces of the TMJ?
hyaline cartilage
31
What connects the bones of the TMJ?
the joint capsule
32
What composes the joint capsule of the TMJ?
fibrous CT
33
What lines the non weight bearing surfaces of the TMJ?
synovial membranes
34
What are the muscles of mastication innervated by?
They are all innervated by V3 (mandibular division of the trigeminal nerve). they are more specifically innervated by branchiomotor fibers of this.
35
What are the muscles of mastication derived from? How does this fit with its innervation?
They are all derived from the 1st pharyngeal arch. This makes sense then why they are all innervated by branchiomotor fibers of the trigeminal nerve.
36
What are the branchiomotor fibers that innervate the muscles of mastication called?
SVE: special visceral efferent
37
When you cut thru the skin & are looking @ the muscles around the mandible...which is most prominent?
the masseter muscle
38
Describe the position & connection pts of the masseter.
runs a little posteriorly as you move inferiorly.
* *attaches to zygomatic arch
* *attaches to body, ramus of mandible, inferior angle of mandible
39
What is the main action of the masseter?
elevation of the mandible (closing the mouth)-->towards the zygomatic arch
**this makes sense b/c the origin & insertion are the in the same sagittal plane-->not as good at side to side movements. Plays a small role, though, in lateral grinding.
40
What are the 4 muscles of mastication?
Masseter
Temporalis
Medial Pterygoid
Lateral Pterygoid
41
What are the actions of the anterior fibers of the temporalis muscle?
anterior fibers are oriented vertically & help in elevating the mandible & closing the mouth. They move the coronoid process of the mandible closer to the temporal bone
42
What are the actions of the posterior fibers of the temporalis muscle?
posterior fibers are oriented horizontally & help in retracting the mandible & closing it when it is open wide & protracted.
**these fibers are also involved in grinding motions.
43
What is the origin & insertion of the lateral pterygoid muscle? What is its main action?
Origin: lateral pterygoid plate
Insertion: condyle & articular disc of TMJ/Mandible
Action: protraction of the mandible
44
What is the origin & insertion of the medial pterygoid muscle? What is its main action?
Origin: medial side of the lateral pterygoid plate
Insertion: medial border of the ramus & angle of the mandible
Action: Elevation of the mandible, closing the mouth
45
What is the similar muscle to the medial pterygoid muscle?
the masseter. The medial pterygoid is just deeper. They run in a similar direction & are both muscles of mastication.
46
Which muscle of facial expression is deep & can be seen near the pterygoids?
the buccinator!
47
What innervates (motor) the buccinator? Which cranial nerve is this from? Which primordial thing is this derived from?
the buccal branch of the facial nerve (CN7) innervates this (motor).
The buccal branch of the trigeminal nerve (CN5) gives sensory innervation to the inside of the cheek.
**buccinator is derived from the 2nd pharyngeal arch--makes sense why the facial nerve innervates it.
48
Which major duct passes thru it?
the duct of the parotid gland...pops in around the 2nd molar.
49
Grinding the teeth involves most of the muscles b/c it is such a complex action. Which actions are included in this movement?
protraction & retraction
| elevation & depression of the mandible
50
Which muscles are involved in elevating the mandible?
masseter
temporalis
medial pterygoid
51
Which muscles are involved in depressing the mandible?
lateral pterygoid
52
Which muscles are involved in protraction of the mandible? Which of these muscles is the most powerful?
Most powerful: lateral pterygoid
| Others: masseter, medial pterygoid
53
Which muscles are involved in retraction of the mandible?
temporalis (posterior fibers)
54
Which muscles are involved in rotation/grinding movement of the jaw?
Temporalis
Medial Pterygoid
Lateral Pterygoid
**only slight the masseter
55
What can be seen in the superficial infratemporal fossa?
```
TMJ
Medial & Lateral Pterygoid Muscles
Inferior Alveolar Nerve
Lingual Nerve
Buccal Nerve
Buccinator
External Carotid artery
Branches of the Maxillary Artery
```
56
Where do you find the inferior alveolar & lingual nerves?
You find them coursing b/w the bellies of the pterygoid muscles.
57
If you do a deep dissection in the infra temporal fossa & really remove all of the excess stuff, including the lateral pterygoid muscle...what do you find?
the maxillary artery & its branches
| the V3 nerve & its branches.
58
What are the branches off of the maxillary artery?
```
MIMS
M: Middle Meningeal Artery
I: inferior alveolar artery
M: Muscular Branches
S: Sphenopalatine artery
```
59
Which branch off the maxillary artery goes up thru the foramen spinosum into the cranial cavity?
the middle meningeal artery
60
What does the middle meningeal artery supply once it is in the cranial cavity?
the dura, bones, meninges where they attach to the calvaria
61
Which nerve courses around the middle meningeal artery? What is this a branch of?
the auriculotemporal nerve courses around the middle meningeal artery & this is a branch off of V3.
**it supplies some cutaneous innervation to the ear.
62
What are the branches off of V3 that can be seen in the infra temporal fossa (deep)?
```
Auriculotemporal nerve
Inferior alveolar nerve
mylohyoid nerves
Lingual nerve
Buccal nerve (sensory)
Motor branches to
Muscles of mastication
```
63
The external carotid artery splits into 2 terminal branches. What are they? Which one goes into the infra temporal fossa?
```
Superficial Temporal Artery
Maxillary Artery (dives into the infra temporal fossa)
```
64
After the maxillary artery gives off all of its branches-->where does it go?
it goes into the pterygomaxillary fissure & then supplies the pterygopalatine fossa
65
What's the deal w/ the sphenopalatine artery?
This seems to come from the maxillary & supplies the sphenopalatine fossa (accessed via the ptergyopalatine fossa). This is responsible for nosebleeds.
66
What are the 2 main muscle branches off of the maxillary artery?
the anterior & posterior deep temporal arteries...they come off of the maxillary artery & supply the temporalis muscle
67
Once again, what is the first branch off of the maxillary artery & which foramen does it pass thru?
the middle meningeal artery ends up going thru the foramen spinosum into the cranial cavity.
68
What's the deal w/ the inferior alveolar artery?
This is a branch off of the maxillary artery & it travels w/ the inferior alveolar nerve into the mandible & supplies the teeth.
69
T/F The middle meningeal artery makes noticeable grooves in the tissue of the brain.
False. More like it makes noticeable grooves b/w the dura & calvaria bone part. Can see it on the inside of the skull.
70
So...the middle meningeal artery supplies the dura & can be easily torn w/ a fracture to the skull. The skull is particularly vulnerable to fracture in the temporal region. If this happened, what would occur?
Epidural Hematoma
71
What branches does the middle meningeal artery give off?
Anterior & posterior branches that supply most of the dura in the cranial cavity.
72
Which structure is found above the foramen ovale where V3 exits the cranial cavity?
the trigeminal ganglion
73
What's the deal w/ V1 & V2? Where do these poor guys travel?
So...V3 is the first branch off.
| V1 & V2 travel along the sphenoid bone in the cavernous sinus.
74
Describe the branching on a basic level of V3.
Starts off as an undivided trunk. This gives off 4 branches (MMTT). Then it splits into an anterior & posterior division. The anterior division is mainly motor w/ 1 sensory. The posterior division is mainly sensory w/ 1 motor. The anterior division has 5 branches (BLMAP). The posterior division has 3 branches (ALI) & another branch off the I.
75
What are the specific nerves that branch off of the undivided trunk of V3?
M: Meningeal
M: Medial Pterygoid (motor)
T: Tensor Veli Palatini
T: Tensor Tympani
76
What are the branches that come off of the anterior division of V3?
```
B: buccal (sensory)
L: Lateral Pterygoid
M: Masseteric
A: Anterior Deep Temporal Nerve
P: Posterior Deep Temporal Nerve
```
77
What are the branches that come off of the posterior division of V3?
A: auriculotemporal nerve
L: Lingual
I: inferior alveolar nerve
**off the inferior alveolar nerve-->mylohyoid nerve. (MOTOR)-->comes off before IA nerve goes into the mandibular foramen
78
The tensor veli palatini has to do with which structure?
the ear
79
The tensor tympani serves which fcn?
it dampens loud noises to protect the ear.
80
What is the fcn of the lingual nerve off V3?
It supplies both general sense & taste to the tongue.
81
What does the mylohyoid branch off the inferior alveolar nerve supply?
this gives motor innervation to the mylohyoid muscle on the floor of the oral cavity.
82
What is another name for the trigeminal ganglion?
semilunar ganglion
83
What are the names for the 3 divisions of the trigeminal nerve?
V1: opthalmic
V2: maxillary
V3: mandibular
84
Where does the mental nerve come from?
This is a sensory continuation of the inferior alveolar nerve. Once it is done innervating the teeth it pops out the mental foramen as the mental nerve & gives sensory innervation there.
85
T/F The V3 branch is partially located w/i the cavernous sinus.
False. It isn't at all. It goes into the foramen ovale. V1 & V2 are found in the sinus. V3 isn't about that life.
86
Do the motor fibers of V3 synapse in the semilunar ganglion?
No. They go to a motor root of the trigeminal nerve.
87
Do the motor & sensory fibers come from the same nucleus in the brainstem?
NO.
General Sensory from the Chief Sensory Nucleus
Motor from the Motor V
88
There is motor & then 3 types of sensation that we talk about with the trigeminal nucleus. What are the 3 types of sensation?
Proprioception
Pain & Temp
General Sensory-2 pt discrimination, vibrational sense etc.
89
Describe the shape of the trigeminal nucleus.
It is really long. Its main portion is a large swelling in the pons. There is also a portion that extends rostrally called the mesencephalic nucleus and a portion that extends caudally called the spinal nucleus V.
90
Where does proprioceptive info go?
to the rostral component of the trigeminal nucleus. The Mesencephalic nucleus.
91
Where does the pain & temp info go?
to the caudal component of the trigeminal nucleus. The spinal nucleus V.
92
Where does the general sensory, vibrational sense & 2 pt discrimination info go?
to the pons swelling in the trigeminal nucleus to chief sensory V
93
Where does the motor info go for the trigeminal nerve?
to the pons swelling in the trigeminal nucleus to motor V
94
What are 2 possible things that can happen to the info that goes to chief sensory nucleus in the pons swelling?
it can go up to the brain for conscious awareness
| it can be involved in reflexes.
95
What type of a reflex would it be if you shut your eyes after something brushes up against them?
5-7 reflex.
96
What type of reflex would it be if you shut your eyes after you see something flying at you?
2-7 reflex.
97
The pain & temp info that descends to the spinal nucleus V travel on a tract. What is this tract called?
the spinal tract V
98
The root of the 5th cranial nerve enters the pons in the _________.
middle cerebellar peduncle. Then it gets to the different nuclei & tracts.
99
Which muscles are innervated by the motor fibers of V3?
```
muscles of mastication
tensor tympani
tensor veli palatini
mylohyoid
anterior belly of the digastric
```
100
T/F There are 3 cranial nerves that have only general sensory input & branchiomotor input.
False. There is only one. The trigeminal nerve.
101
If a cranial nerve is only carrying branchiomotor & visceromotor...which one is it?
Oculomotor.
102
What supplies motor innervation to the muscles of mastication?
branchiomotor innervation from V3. Considered SVE
103
What supplies sensory innervation (GSA) to lower teeth, general sense of tongue, oral cavity surface, skin anterior to the ear?
these are all supplied by V3. GSA
104
What supplies taste to the tongue? What is this considered?
Considered special visceral afferent. SVA. Gustatory nucleus.
Cranial Nerve 7-->anterior 2/3 tongue
Cranial Nerve 9-->posterior 1/3 tongue
Cranial Nerve 10-->epiglottis
105
What innervates the parasympathetics that is of note?
parasympathetics. Means they come out of GVE.
They are all innervated by Cranial Nerve 7 in the head & neck, except for the parotid gland-->Cranial Nerve 9.
**However, they hop on the Cranial Nerve 5 to get to their targets.
106
3, 7, 9, 10 will be found in GVE. But where in the brain are 3, 7, 9, found?
3--midbrain
7--pons
9--medulla
107
Which salivary glands are found in the infra temporal region? What are they innervated by?
Submandibular Gland--CN 7
Sublingual Gland--CN 7
Parotid Gland--CN 9
108
We know that the parasympathetics that supply the submandibular & sublingual glands hop on a V bus. Which one?
the CN 7 fibers to the 2 glands both hop on a V3 bus. The lingual nerve branch to be exact.
109
The parasympathetics that supply the submandibular & sublingual glands need to synapse before they hit their target cell. Where do they go to do that? Hint: they go to the same place.
They both go to the submandibular ganglion. This is attached to the lingual nerve & submandibular gland.
110
What are the parasympathetic fibers riding on before they hop onto the Lingual Nerve V3 bus?
A branch of CN7, the chorda tympani nerve.
111
Where does the chorda tympani come from? What is its journey? It carries parasympathetics, but what else does it carry?
It comes from CN7. It branches off before it exits the stylomastoid foramen, in the middle ear cavity. Then it exits a separate hole than the facial nerve does. It exits the petrotympanic fissure. Then it hops on the lingual nerve.
It also carries SVA taste to the anterior 2/3 of the tongue. This of course, does not synapse in the submandibular ganglion.
112
T/F The lingual nerve ONLY carries preganglionic parasympathetics.
False. It also carries a few postganglionic parasympathetics out to the sublingual gland.
113
The petrotympanic fissure appears quite close to which structure? So close it almost looks like what would crush it?
So close to the mandibular fossa.
| It almost looks like the condylar process of the mandible would crush it.
114
The CN VII enters the brainstem in the ____. At the point of entry there is a nucleus for which 2 things? There is no nucleus for ____. Where do these fibers have to go to find a place to dump of their info?
* pons
* *branchiomotor SVE and visceromotor (salivation) GVE
* *taste-->SVA
* *taste fibers have to travel down the nucleus solitariis tract.
115
T/F If there were fibers for GVA on CN7 they would have to travel down the nucleus solitariis tract too.
True.
116
What is the significance of the nucleus ambiguus? What is found next to it?
this is the pt where CN9 enters or leaves the brainstem.
**next to it is a small nucleus called inferior salivatory nucleus. This is GVE/Visceromotor-->a place for parasympathetics.
117
What does the inferior salivatory nucleus supply?
the secretory parasympathetic fibers from CN9
they are preganglionic
they will synapse in the otic ganglion
they will eventually innervate the parotid gland
118
Aside from being next to the nucleus ambiguus what else is the inferior salivatory nucleus next to?
branchiomotor nuclei for CN 9 & CN10
119
Which fibers are found in the superior salivatory nucleus? What is this located next to?
here are found preganglionic secretory parasympathetic fibers from CN7
they are located next to the branchiomotor nucleus for CN7.
they will go on to synapse in the submandibular ganglion & supply the submandibular & sublingual glands.
120
What is the clinical relevance of the route of the lesser petrosal nerve from the brainstem to the parotid gland?
if you have a massive infection in the middle ear cavity...this could decrease your salivary secretions via the chorda tympani nerve & the lesser petrosal nerve.
121
Describe the circuitous route of the CN9 parasympathetic fibers to the parotid gland.
Inferior Salivatory Nucleus
Leaves skull via Jugular Foramen
CN9 gives off tympanic nerve branch
This reenters skull via tympanic canaliculus
Now in middle ear cavity
Tympanic plexus sits on promontory
Leaves ear cavity & enters main part of skull via lesser petrosal hiatus
Goes along the petrous portion of the temporal bone
Leaves skull via the foramen ovale
Synapses in the otic ganglion
Hops on a Posterior Division V3 branch (Auriculotemporal nerve)
Goes to the parotid gland & causes secretion.
