Infratemporal fossa Flashcards

1
Q

What is the boundaries of the temporal fossa?

A

• Temporal Fossa: shallow depression on side of skull that funnels inferiorly to pass below zygomatic arch & end at base of skull; separated from Infratemporal Fossa by the Infratemporal Crest
o Posterior & Superior= Superior & Inferior temporal lines
o Anterior= Frontal & Zygomatic Bones
o Lateral= Zygomatic Arch
o Inferior= Infratemporal Crest

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2
Q

What is the contents of the temporal fossa?

A

temporalis muscle fills the temporal fossa

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3
Q

What are the boundaries of the infratemporal fossa?

A

o Lateral= Ramus & Condyle of Mandible
♣ Features= LINGULA; MANDIBULAR FORAMEN & CANAL
o Medial= Lateral Pterygoid Plate
♣ Features= PTERYGOMAXILLARY FISSURE
o Anterior= Posterior Aspect of Maxilla
♣ Features= ALVEOLAR FORAMINA
o Posterior= Tympanic Plate; Mastoid & Styloid Processes of Temporal Bone; not bony
o Superior= Inferior Surface of Greater Wing of Sphenoid Bone; Squamous Temporal Bones
♣ Features= FORAMEN OVALE; FORAMEN SPINOSUM
o Inferior= Where medial pterygoid attaches to mandible near its angle; open

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4
Q

What are the contents of the infratemporal fossa?

A

o Contents Inferior part of temporalis muscle; Lateral & Medial Pterygoid; Maxillary Artery and branches; Pterygoid Venous Plexus; Mandibular, Inferior Alveolar, Lingual, Buccal, & Chorda Tympani Nerves; Otic Ganglion

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5
Q

What are the actions of the TMJ?

A

• TEMPOROMANDIBULAR JOINT (TMJ)= modified hinge-type synovial joint allowing movement in 3 planes
o Actions: Gliding/Excursion (protrusion/retrusion); depression; elevation

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6
Q

What forms the TMJ?

A

o Bony Articulating Surfaces:
♣ Mandibular Head/Condyle (inferior)
♣ Articular Tubercle of Temporal Bone (superior, anterior)
♣ Mandibular Fossa of Temporal Bone (superior, posterior)
o surrounded by FIBROCARTILAGE (rather than hyaline cartilage) Fibrous Joint Capsule (loose)
o Articular Disc= divides joint cavity into 2 separate synovial compartments; dense fibrous tissue between condyle & mandibular fossa
♣ Biconcave Discthickened posteriorly; less prominent anterior thickening
♣ Upper Compartment= Translatory Movement (Gliding)
♣ Lower Compartment= Hinge Movement

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7
Q

What ligaments stabilize the TMJ?

A

o Ligaments of TMJ: connect mandible to the cranium
♣ INTRINSIC:
• LATERAL LIGAMENT OF TMJ= thickened portion of joint capsule to prevent posterior & inferior dislocation of joint; strengthens joint
♣ EXTRINSIC:
• STYLOMANDIBULAR LIGAMENT runs from styloid process to angle of mandible; does NOT contribute to strength of joint
• SPHENOMANDIBULAR LIGAMENT runs from spine of sphenoid to lingual of mandible medial to TMJ; check ligament for movement of extension at TMJ
o PRIMARY PASSIVE SUPPORT OF MANDIBLE (active support= muscles of mastication)

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8
Q

What muscles act on the TMJ?

A

The muscles of mastication produce movement of mandible at TMJ

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9
Q

What nerve provides sensory innervation to this joint and would carry pain if damaged?

A

♣ AURICULOTEMPORAL NERVE (sensory innervation from CN V3) & SUPERFICIAL TEMPORAL ARTERY (smaller terminal branch of ECA)
• anterior portion also innervated by nerve to masseter & supplied by small muscular branches of maxillary artery

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10
Q

What causes clicking of TMJ?

A

minor disc displacement or osteoarthritis

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11
Q

Describe dislocation of TMJ

A

The mandibular head displaces anterior to the auricular tubercle, should be prevented muscles

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12
Q

What is the innervation of the muscles of mastication?

A

• Muscles of Mastication are innervated by the MOTOR FIBERS OF CN V3 (MANDIBULAR DIVISION OF TRIGEMINAL NERVE)
o all muscles are derivatives of 1st pharyngeal arch
o Nerve to Medial Pterygoid
o Nerve to Lateral Pterygoid
o Nerve to Masseter
o Deep Temporal Nerve

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13
Q

What muscles act to close the mouth?

A

• MOUTH CLOSURE/ ELEVATION OF MANDIBLE
o Medial Pterygoid (bilateral contraction)
o Temporalis Muscle (anterior fibers; bilateral contraction)
o Masseter Muscle (bilateral contraction)

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14
Q

What muscles act to open the mouth?

A
•	OPEN MOUTH/ DEPRESSION OF MANDIBLE
o	Lateral Pterygoid (bilateral contraction; inferior heads)
****main assistor
o	Suprahyoid
o	Infrahyoid
o	Platysma
***against resistance
*** but really gravity is the main player
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15
Q

What muscles retrude mandible?

A

o Temporalis Muscle (posterior fibers; bilateral contraction)**main player
o Digastrics
o Geniohyoid

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16
Q

What muscles protrude the mandible?

A

o Masseter Muscle (bilateral contraction; superficial fibers)
o Lateral Pterygoid (bilateral contraction)*only assists
o Medial Pterygoid (bilateral contraction)

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17
Q

What muscles are involved in the side to side movements of mandible?

A
•	SIDE-TO-SIDE MOVEMENTS OF MANDIBLE contraction produces movement to contralateral side (left side contraction= right lateral movement; right side contraction= left lateral movement)
o	Lateral Pterygoid (unilateral contraction)
Medial Pterygoid (unilateral contraction)
18
Q

The maxillary artery is a terminal branch of what vessel?

A

• MAXILLARY ARTERY= larger terminal branch of External Carotid Artery
o arises posterior to neck of mandiblepasses deep to neck of mandible passes anteriorly superficial/deep to lateral pterygoid courses through pterygomaxillary fissure to enter pterygopalatine fossa

19
Q

2 terminal branches of ECA are:

A

Maxillary and superificial temporal aa.

20
Q

How is maxillary artery divided into 3 segments?

A

By their relation to lateral pterygoid muscle.

21
Q

Describe 1st part of maxillary artry

A

**All go into bone, mandibular portion, posterior to mandible
5 branches, 2 important:
middle meningeal- supplies dura mater and calvaria via foramen spinosum
inferior alveolar artery- into mandibular foramen and canal, supplies manidble and teeth, gives off mental a.

22
Q

Describe 2nd part of maxillary artery

A

pytergoid portion, all supply muscles, 4 branches

1) deep temporal- (ant and post) supply temporalis m.
2) ptyergoid aa.- supply lateral and medial pyterygoid
3) a. to masseter- supplies masseter
4) buccal- buccinator

23
Q

Describe 3rd part of maxillary artery

A

Pterygopalatine portion, near or in fossa

1) posterior superior alveolar artery- supplies maxillary molar and premolar teeth, maxillary sinus
2) infraorbital artery- inferior eyelid, lacrimal sac, side of nose and upper lip

24
Q

What would be affected by ligation of 1st part of maxillary artery

A

• Blockage/Ligation of Mandibular Portion (1st segment):

o external acoustic meatus; tympanic membrane; middle ear cavity; dura mater; calvaria; mandible; lower teeth; chin

25
Q

What would be affected by ligation of second part of maxillary artery?

A

• Blockage/Ligation of Pterygoid Portion (2nd Segment):

o Temporalis muscle; lateral & medial pterygoid ; deep surface of masseter; buccinators

26
Q

What would be affected by ligation of third part of maxillary artery?

A

• Blockage/Ligation of Pterygopalatine Portion (3rd Segment):
o upper molars & pre-molars; inferior eyelid; lacrimal sac; roof of phaeynx; pharyngotympanix tube; lateral nasal wall; nasal septum

27
Q

What is the pterygoid venous plexus and what does it communicate with?

A

• Pterygoid Venous Plexus venous equivalent of maxillary artery; valveless; located party between temporal & pterygoid muscles; drains anteriorly into the facial vein via deep facial vein BUT drains largely posteriorly via maxillaryretromandibular veins (drains to EJV)
o Communications:
♣ Retromandibular Vein
♣ Facial Vein
♣ Inferior Ophthalmic Vein
♣ Cavernous Sinus** (directly or via facial to inferior op to cav sinus)
♣ Pharyngeal Plexus

28
Q

What types of fibers are carried in CN V3? What opening in the skull does it pass through? What other parasympathetic nerve passes through the same opening?

A

• CN V3= Mandibular Division of Trigeminal Nerve:
o MIXED NERVE (SENSORY + MOTOR)
o nerve of mandibular process of 1st branchial/pharyngeal arch
o arises within MIDDLE cranial fossa from Trigeminal Ganglion descends through FORAMEN OVALE to reach infratemporal fossa
♣ Lesser Petrosal Nerve (PREganglionic PARAsympathetic) of the Glossopharyneal Nerve (CN IX) also travels through the FORAMEN OVALE to synapse in the otic ganglion (inferior to foramen ovale, medial to root of CN V3)

29
Q

List the motor branches on V3 and what they supply

A

• MOTOR BRANCHES:
o Muscles of Mastication
♣ Deep Temporal Nerves anterior, middle, posterior; supply temporalis muscle
♣ Masseteric Nerve/ Nerve to Masseter passes through mandibular notch to supply masseter muscle
♣ Nerve to Lateral Pterygoid supplies lateral pterygoid
♣ Nerve to Medial Pterygoid supplies medial pterygoid
o Other Muscles (Pharyngeal/ Branchial Arch 1 Muscles)
♣ Nerve to Tensor Tympani supplies tensor tympani muscle
♣ Nerve to Tensor Veli Palatini supplies tensor veli palatini muscle
♣ Nerve to Mylohyoid supplies mylohyoid & anterior belly of digastric muscles (branch off interior alveolar)

30
Q

List sensory branches of V3 and what they supply

A

• SENSORY BRANCHES:
o Auriculotemporal Nerve
♣ 2 roots that encircle middle meningeal artery
♣ divides into numerous branches; largest portion passes posterior to neck of mandible & then travels with superficial temporal vessels
♣ Supplies sensory fibers to TMJ; anterior ear (auricle & external meatus); anterior surface of tympanic membrane; temporal region
♣ POSTganglionic PARAsympathetic fibers (secretomotor) to the parotid gland from lesser petrosal nerve (CN IX) hitch a ride on auriculotemporal nerve from otic ganglion
o Inferior Alveolar Nerve
♣ appear from under inferior border of lateral pterygoid & then travels between medial pterygoid & mandibular ramus
♣ Enters mandibular foramen (marked by lingual) to enter mandibular canal, receiving sensory fibers from mandibular teeth
♣ within mandibular canal gives off MENTAL NERVE (passes through mental foramen & conducts sensory information from skin & mucous membranes of lower lip & skin of chin; vestibular gingiva of mandibular incisors)
o Lingual Nerve
♣ appears from under inferior border of lateral pterygoid musclepasses over lateral aspect of medial pterygoidheads toward lingual aspect of 3rd mandibular molar alveolar area
♣ enters mouth between medial pterygoig & ramus of mandible to travel anteriorly in floor of mouth under oral mucosa
♣ conducts sensory (pain, temperature, touch) from anterior 2/3 tongue; mucosa of floor of mouth; mandibular lingual gingivae
♣ Buddy= Chorda Tympani
• PREganglionic PARAsympathetic fibers (secretomotor) hitch a ride to synapase at submandibular ganglion to supply submandibular & sublingual glands
• TASTE (special sensory) fibers from anterior 2/3 of tongue hitch a ride
o Long Buccal Nerve/ Buccal Nerve of CN V3
♣ emerges between 2 heads of lateral pterygoid
♣ runs anterior on buccinator muscle pierces muscle (DOES NOT SUPPLY IT)
♣ conducts sensory branchs from skin over cheek, mucous membrane lining the cheek, buccal surface of mandibular buccal gingiva of molar region

31
Q

LESION OF CN V3 AT FORAMEN OVALE:

A

o Loss of sensory to anterior ear, TMJ, temporal region, & tympanic membrane
o Loss of mastication
o Soft palate doesn’t raise when asked to say “ahh” (tensor veli palatini)
o Mylohyoid & Digastric affected cannot retrude; some difficult depressing mandible with resistance
o Loss of sensory of skin & mucous membranes of lower lip & mandibular teeth; chin (inferior alveolar & mental)
o Loss of sensor of mucous membrane of cheek & skin of cheek & buccal gingivae (long buccal nerve)

32
Q

LESION OF CN V3 AT MANDIBULAR FORAMEN:

A

• Sensory loss of mandibular teeth to median plane, skin & mucous membrane of lower lip, labial alveolar gingiva, & skin of chin
o Effects Inferior Alveolar & Mental Nerve

33
Q

LESION OF CN V3 IN FLOOR OF MOUTH:

A

• Loss of sensation (pain, temperature, touch) of floor of mouth & tongue; loss of taste of anterior 2/3 of tongue
o Lingual Nerve (+ Chorda Tympani) affected

34
Q

What branch of CN V3 do the parasympathetics from the otic ganglion hitch a ride on?

A

• Parasympathetics from otic ganglion hitch a ride on the AURICULOTEMPORAL NERVE to provide secretomotor innervation to parotid gland

35
Q

Where is the otic ganglion found? With what cranial nerve is it associated?

A

• OTIC GANGLION= located inferior to FORAMEN OVALE, MEDIAL TO ROOT OF CN V3, & POSTERIOR TO MEDIAL PTERYGOID MUSCLE
o receives PREganglionic PARAsympathetic fibers from LESSER PETROSAL NERVE (GLOSSOPHARYNGEAL NERVE/ CN IX)
o POSTganglionic PARAsympathetic fibers hitch a ride on auriculotemporal nerve to reach parotid gland

36
Q

What does the inferior alveolar nerve become after it exits the mandible?

A

• Inferior Alveolar Nerve becomes the MENTAL NERVE after emerging through mental foramen

37
Q

What branch of CN V3 do parasympathetics from the submandibular ganglion hitch a ride on?

A

• PARAsympathetics from the submandibular Ganglion traveling within CHORDA TYMPANI (branch of Facial Nerve/ CN VII) hitch a ride on the LINGUAL NERVE (branch of CN V3)

38
Q

What would result if chorda tympani were lesioned proximal to (before) its union with the lingual nerve?

A

Loss of taste sensation from anterior 2/3 of tongue; loss of submandibular & submental glands

39
Q

What would result if the lingual nerve were lesioned proximal to (before) its union with chorda tympani?

A

• Taste would be intact, but general sensation (pain; temperature; touch) from anterior 2/3 of tongue & floor of mouth would be lost

40
Q

What would result if the lingual nerve were lesioned distal to its union with chorda tympani?

A

• BOTH taste (special sensation) & general sensation (pain; temperature; touch) would be lost, as well as function of submandibular & submental glands

41
Q

What would result if lingual nerve were lesioned distal to the submandibular ganglion?

A

• loss of function of submental glands