Sievert: Infratemporal fossa Flashcards by Megan Foggia

What is the only division of the trigeminal nerve that carries both motor and sensory information?

V3 is the only division

**V1 and V2 are only sensory

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Where is the infratemporal fossa located?

deep to the mandible

inferior to the zygomatic arch

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What are the boundaries of the infratemporal fossa?
Anterior?
Medial?
Lateral?
Posterior?

ant - maxillary bone
medial - lateral pterygoid plate
lateral - ramus of mandible
posterior - parts of the temporal bone

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What is significant about the following features of the mandible?
Condyle and coronoid process
Mandibular notch

Condyle and coronoid process are for the attachment of muscles
Mandibular notch allows for small nerves to pass thru

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What is the opening between the styloid process and the mastroid process? What nerve passes through here?

stylomastoid foramen; cranial nerve 7 passes through here **it is almost entirely motor as it passes through and gives off its 5 terminal branches

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What is located between the pterygoid plate and the maxillary bone? Why is this important?

pterygomaxillary fissure; it is a way for things to get into and out of the pterygopalatine fossa

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What does the foramen ovale allow for?

the passage of V3 into infratemporal fossa from the cranial cavity

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What does the foramen spinosum allow for?

passage of middle meningeal artery from infratemporal fossa to cranial cavity

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Where do blood vessels and nerves to the mandible (lower teeth) enter?

mandibular foramen

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The temporomandibular joint has two joint cavities - a superior joint cavity, a disc, and an inferior joint cavity. It has a ligamentous capsule surrounding the whole thing. What muscle of this joint attaches to both the condyle and the disc, and pulls both of these structures anteriorly to aid in mastication?

lateral pterygoid muscle

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When the jaw opens, what happens to the condyle?

It moves anteriorly on the mandibular fossa and rides forward

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How do you get wide opening of the TMJ?

protraction of the condyle in the mandibular fossa and on top of the articular tubercle

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What does extreme protraction cause the muscles of mastication to do?

Causes these muscles to contract forcefully

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What must occur for the jaw to open widely?

protraction

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This muscle attaches to the condyle and also has one head that goes to the disc. When this muscle contracts, it pulls from posterior to anterior, and the condyle slides down onto the articular tubercle.

Lateral pterygoid

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Which movements of the TMJ occur in the lower joint cavity?

elevation and depression

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Which movements of the TMJ occur in the upper joint cavity?

protraction and retraction

**both the disc and the condyle are being pulled forward by the lateral pterygoid muscle

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How do you get a grinding motion of the jaw?

Use a combination of protraction/retraction and elevation/depression to create side-to-side movements of the jaw.
**use alternating sides

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What are two important ligaments of the TMJ?

sphenomandibular

stylomandibular

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What muscle is the main protractor that pulls the condyle toward the pterygoid plates?

lateral pterygoid

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The lateral pterygoid muscle has two heads? Where do they insert?

one head goes to the disc, one head goes to the condyle.

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(blank) cartilage covers the articular surfaces of the temporomandibular joint. A joint (blank) connects the bones. Synovial membranes line non-weight bearing surfaces.

hyaline; capsule

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Does the TMJ have a high range of motion?

Yes, compared to other joint types

**due to its gliding motion

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Elevation and depression of the jaw are (blank) movements, while protraction and retraction are (blank) movements

hinge; gliding

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What kind of dislocation is the TMJ most prone to?

anterior dislocation when jaw is open wide | **head of mandible displaced anterior to articular tubercle

What 3 things are found in the infratemporal fossa?

muscles of mastication branches of the mandibular nerve **V3 which has various branches branches of the maxillary artery **4 branches

What type of fibers are necessary for muscles of mastication?

branchiomotor!

Where do all muscles of mastication come from? What are they innervated by?

the first branchial arch; | the mandibular division of the trigeminal nerve **only division with motor in addition to sensory

What does the masseter muscle do? What is it not good at?

it is a powerful elevator of the mandible **closer of the jaw, brings the mandible up toward the zygomatic arch

The temporalis muscle has both anterior and posterior fibers. How are the anterior fibers oriented? What do they do? How are the posterior fibers oriented? What do they do?

anterior fibers are vertically oriented and contribute to elevation of the mandible; posterior fibers are horizontally oriented and contribute to retraction of the mandible

What nerve supplies the temporalis and masseter muscles?

motor fibers of V3

What are the two pterygoid muscles? Where do they both arise from? What are they innervated by?

medial and lateral pterygoid muscles; they both arise from the lateral pterygoid plate; they are innervated by motor fibers of V3

The lateral pterygoid muscle goes from the lateral pterygoid plate to what two things?

the condyle and the disc

What are the actions of the masseter muscle?

elevation | protraction

What are the actions of the temporalis muscle?

elevation retraction rotation

What are the actions of the lateral pterygoid muscle?

depression protraction rotation

What are the actions of the medial pterygoid muscle?

elevation protraction rotation

Rotation, or side to side grinding movements, combines primary actions of at least (blank) muscles, alternating sides

Is the buccinator a muscle of mastication? What is it innervated by?

no, it is a muscle of facial expression; the buccal branch of cranial nerve 7

The buccal branch of cranial nerve 5 and the buccal branch of cranial nerve 7 are named identically. How are they different?

the buccal branch of 5 is sensory and takes care of the inside of the cheek; the buccal branch of 7 is branchiomotor

What passes through the buccinator?

parotid duct

Where does the parotid duct empty into the mouth?

enters into the cheek right by the second upper molar

T/F: A sensory branch of cranial nerve 5 passes through the buccinator, but this muscle is innervated by cranial nerve 7.

True

What is the most powerful protractor at the TMJ?

the lateral pterygoid muscle

Where do branches of cranial nerve 5 come out of?

the foramen ovale

What is the artery that branches off of the maxillary artery and enters the foramen spinosum? Why is this artery clinically important? What does it supply?

middle meningeal artery; this artery can cause epidural hematoma; this artery supplies the dura and the bone

What is the nerve that is associated with the middle meningeal artery? This nerve comes off of the mandibular division of cranial nerve 5 after exiting the foramen ovale. It gives off a branch that goes around the middle meningeal artery, then goes posterior and medial to the ramus of the mandible. Finally, it supplies a bit of cutaneous innervation to the ear.

articulotemporal nerve

The external carotid artery comes up and ends in two terminal branches. What are they?

superficial temporal | maxillary **goes deep into the infratemporal fossa

What are two muscular branches off of the maxillary artery that travel underneath the temporalis muscle?

anterior and posterior deep temporal arteries **these are muscular branches

What is the branch off of the maxillary artery that gives blood supply to the teeth?

inferior alveolar artery

What is the first branch off of the maxillary artery that goes through the foramen spinosum?

the middle meningeal artery

Where does the maxillary artery eventually enter?

enters the pterygomaxillary fissure and disappears into the pterygopalatine fossa

What nerve passes through the foramen ovale? | What artery passes through the foramen spinosum?

V3; middle meningeal artery

This artery passes through the foramen spinosum and leaves a depression on the inside of the temporal bone

middle meningeal artery

This artery supplies the dura and can be easily torn following head trauma to the region of the temporal bone

middle meningeal artery

What structures near or in the fossa need somatosensory innervation?

Teeth need sensory innervation **teeth of the lower jaw (upper jaw provided by maxillary division) Tongue needs sensory innervation Oral cavity needs sensory innervation **buccal branch Skin anterior to the ear needs sensory innervation

Where does V3 enter the foramen ovale?

just distal to the trigeminal ganglion

What are the branches of V3 on its undivided trunk?

Meningeal Medial pterygoid Tensor veli palatini Tensor tympani

Is the anterior division of V3 sensory or motor? What are the branches of the anterior division?

``` mostly motor, one sensory Buccal **sensory Lateral pterygoid Masseter Anterior Posterior deep temporals ```

Is the posterior division of V3 sensory or motor? What are the branches of the posterior division?

mostly sensory, one motor Auriculotemporal **to ear Lingual **sensory to anterior 2/3 of tongue Inferior alveolar **mylohyoid is motor off of this branch

This posterior division nerve enters the mandibular foramen and supplies the teeth. Just before entering the foramen, it gives off a motor branch called the mylohyoid branch.

inferior alveolar nerve

Does the mandibular division of cranial nerve 5 enter the cavernous sinus?

No, V3 comes off right after the ganglion, before V1 and V2 continue into the cavernous sinus

What is the ganglion for all 3 divisions of cranial nerve 5?

the semilunar or trigeminal ganglion

What are the three named areas of the trigeminal nucleus?

rostrally - mesencephalic nucelus caudally - spinal nucleus of 5 big swelling in the middle - chief sensory nucleus

Where does info coming in on cranial nerve 5 carrying discriminative touch, vibrational sense, etc from face and head go to?

chief sensory nucleus

Where does info about unconscious proprioception go to?

mesencephalic nucleus | **doesn't enter chief sensory nucleus

Where does info about pain and temp from the face, head, and anterior 2/3 of the tongue go to?

descends to spinal nucleus 5 | **can't synapse in chief sensory nucleus - must descend along the spinal tract of 5

Parasympathetics to the head leave the brainstem with which cranial nerves?

3, 7, and 9

Parasympathetics to the head travel with their respective cranial nerve for a short distance, and then what do they do?!

hitchhike on a branch of cranial nerve 5 to their targets

What do parasympathetics in the infratemporal region supply?

submandibular and siblingual glands | parotid gland

The mandibular division of cranial nerve 5 has what two components?

general sense | branchiomotor

All the glands in the head are innervated by which cranial nerve? What is an exception to this?

cranial nerve 7; except for the parotid gland, which is innervated by cranial nerve 9

There are two types of parasympathetics that pass into the infratemporal fossa. What are they?

parasympathetics for the parotid on cranial nerve 9 parasympathetics for the submandibular, sublingual, and lacrimal glands on cranial nerve 7 **parasympathetics travel on 5 to their targets

What are the three big cranial nerves that take care of parasympathetics?

3, 7, 9

The mandibular nerve comes out of the foramen ovale. What is the nerve that gets really close to the submandibular and sublingual glands?

lingual nerve

Where does the lingual nerve go?

into the tongue

How do parasympathetics get onto the back of the lingual nerve and travel to the two glands (submandibular and sublingual)?

they travel with the chorda tympani **a branch of 7 that comes off inside the middle ear cavity. This branch travels out of the petrotympanic fissure and jumps onto the back of the lingual nerve. Then, it travels to the ganglion, synapses, and travels to the two glands.

What two types of fibers does the lingual nerve carry?

preganglionics from the chorda tympani and postganglionics from the ganglion

Where does the chorda tympani branch off of cranial nerve 7?

as it is leaving the stylomastoid foramen

The CN VII enters the brainstem in the (blank). At the point of entry there is a nucleus for branchiomotor (motor VII) and visceromotor (salivation), but there is no nucleus for taste. Where do the taste fibers have to go to find a place to dump of their info?

pons; down to the medulla in the nucleus solitarius

So, the chorda tympani jumps onto the back of the (blank) nerve. It comes out of the (blank) fissure of the temporal bone.

lingual; petrotympanic

Where must taste and visceral afferent information go after entering the brainstem?

must travel down to the nucleus solitarius

How does cranial nerve 7 enter the temporal bone? Where does it leave the middle ear?

through the internal auditory meatus; remains in the middle ear until it comes out through the stylomastoid foramen

What nerve leaves the skull through the foramen ovale alongside V3? This nerves reforms after innervating some stuff in the middle ear cavity.

lesser petrosal nerve

What does the lesser petrosal nerve carry?

preganglionic parasympathetics only

Where does the lesser petrosal nerve synapse? What does it do after it synapses?

synapses in the otic ganglion, then gives off fibers that jump onto the auriculotemporal nerve, travel around the middle meningeal artery, and come out behind the ramus of the mandible to innervate the parotid gland

The auriculotemporal nerve is primarily (blank) to skin of ear, parotid gland, and fascias. It also carries postganglionic parasympathetic fibers that are secretomotor the the (blank)

sensory; parotid gland

What innervates the parotid gland?

preganglionic sympathetics from cranial nerve 9 to the otic ganglion

The (blank) marks the point where cranial nerve IX enters or leaves the brainstem. There is a small nucleus just next to ambiguus called the (blank) which is a visceromotor nucleus. This gives rise to the preganglionic fibers that synapse on the otic ganglion and then continue on to the parotid

nucleus ambiguus; inferior salivatory

A tiny little nucleus called the (blank) sits next to the branchiomotor column in the medulla and sends preganglionic axons out with cranial nerve 9. These ultimately synapse in a parasympathetic ganglion and reach the parotid gland. Very similar to the superior slaivatory nucleus associated with VII.

inferior salivatory

Cranial nerve 9 leaves the skull through the (blank). What other nerves exit through this foramen?

jugular foramen; cranial nerves 10 and 11

What nerve does cranial nerve 9 give off just before it gives off all of its branches? What course does this nerve take?

gives off the tympanic nerve; this nerve turns around and immediately reenters the skull through the tympanic cannaliculus

Cranial nerve 9 leaves the middle ear cavity to reneter the skull. It then travels on top of the temporal bone, turns and leaves out of the foramen ovale, jumps into the otic ganglion, and supplies the parotid gland. Why is it important to consider the course of this nerve?

If you have a massive infection of your inner ear, this can affect salivation via the chorda tympani and lesser petrosal nerve. Infection can destroy these nerve fibers!

What are the 3 main openings that cranial nerve 9 passes through?

jugular foramen tympanic cannaliculus foramen ovale