Module 8 - Infratemporal Fossa Flashcards
What is important about the sympathetic innervation of the head and neck?
- arises from cervical ganglia (inferior, middle, [mostly] superior)
- no preganglionic cell bodies in cervical region
- preganglionic axons from upper thoracic synapses in cervical ganglia
What is the pathway of the middle ear nerve of the internal carotid nerve (sympathetics)?
- pregang symp > nucleus > internal carotid nerve > courses with internal carotid artery > tympanic plexus
What is the pathway for the deep petrosal nerve of the internal carotid nerve(sympathetic)?
pregang symp > nucleus > internal carotid nerve > courses with internal carotid artery > deep petrosal n > V2 br
What is the pathway for the cavernous sinus branch of the internal carotid n (sympathetic)?
pregang symp > nucleus > internal carotid nerve > courses with internal carotid artery > cavernous sinus > CNs: III, IV, VI, V1, V2
What CNs sympathetics exit the skull directly from the superior cervical ganglia?
- VII
- IX
- X
- XI
- XII
Where do the communicating branches of sympathetic innervation go and what CNs do they communicate with?
- along external carotid artery
- communicate with: V2, V3, VII, IX, X, XII
What is the infra temporal fossa?
- irregular space inferior and eep to zygomatic arch and mandible and posterior to maxilla
What is the lateral boundary of the infratemporal fossa?
ramus of mandible
What is the medial boundary of the infratemporal fossa?
lateral pterygoid plate
What is the anterior boundary of the infratemporal fossa?
posterior maxilla
What is the posterior boundary of the infratemporal fossa?
- mastoid and styloid processes
What is the superior boundary of the infratemporal fossa?
greater wing of sphenoid
What is the inferior boundary of the infratemporal fossa?
mandibular attachment of medial pterygoig
What are the contents of the infratemporal fossa?
- inferior part of temporals
- lateral (sup + inf) and medial (deep + superficial) ptergygoid muscles
- maxillary artery and its branches
What are the muscles of mastication?
- masseter
- temporalis
- lateral pterygoid
- medial pterygoid
What are the OIANs of the masseter?
origin: zygomatic arch
insert: angle of mandible and lateral aspect of ramus
action: elevation, protraction and retraction (deep fibers) of mandible
nerve: mandibular nerve CN V3
What are the OIANs of the temporalis muscle?
origin: temporal fossa
insert: coronoid process and anterior border of the ramus of mandible
action: elevation and retraction of the mandible
nerve: mandibular nerve CN V3
What are the OIANs of the lateral pterygoid muscle?
origin: infratemporal surface of sphenoid and lateral surface of the lateral pterygoid plate
insert: neck of the mandible and TMJ disc
action: depress mandible, protracts and acts with ipsilateral medial pterygoid to rotate mandible to produce the side to side movement of chewing
nerve: mandibular nerve CN V3
What are the OIANs of the medial pterygoid muscle?
origin: medial surface of lateral pterygoid plate and adjacent maxilla
insert: medial aspect of angle of mandible
action: elevation of mandible and acts with ipsilateral lateral pterygoid to rotate th maxilla to produce side to side movement during chewing
nerve: mandibular nerve CN V3
What nerves are found in the infratemporal fossa?
mandibular CN V3
- auriculotemporal
- inferior alveolar
- lingual
- chorda tympani
otic ganglion
What is the importance of the pterygoid plexus in the spread of infection to the cranial cavity?
- due to communication with cavernous sinus, infection of superficial face may spread to cavernous sinus, causing cavernous sinus thrombosis
What are the components of the temporomandibular joint (TMJ)?
- temporal = mandibular fossa of temporal bone
- mandibular = head of mandible
- fibrocartilage articular cartilage
- articular tubercle
What are the ligaments of the TMJ?
- lateral ligament
- stylomandibular ligament
- joint capsule
- sphenomandibular ligament
What are the attachments of the lateral ligament of the TMJ?
condyle process > zygomatic arch
What are the attachments of the stylomandibular ligament of the TMJ?
styloid process > angle of mandible
What are the attachments of the sphenomandibular ligament?
sphenoid bone > ramus of mandible
What are the nerves that innervate the TMJ?
sensory: branches of V3
- auricularotemporal nerve
- deep temporal nerve
- masseteric nerve
(articular branches)
1st branchial arch derivative innervated by CN V3
What are the movements of the TMJ?
- elevation (closing mouth)
- depression (opening mouth)
- protrusion
- retrusion
- lateral
What are the muscles that control the elevation (closing) of TMJ?
- temporalis
- masseter
- medial pterygoid
What muscles control depression (opening) of the TMJ?
- lateral pterygoid
- suprahyoid muscles
- infrahyoid muscles
- mainly gravity
What are the muscles that control protrusion of the TMJ?
- lateral pterygoid
- messier
- medial pterygoid
What are the muscles that control retrusion of the TMJ?
- temporalis
- masseter
What are the muscles that control the lateral movement of the TMJ?
- same side temporalis
- opposite side pterygoids
- opposite side masseter
mandible to left:
- L temporalis
- R masseter
- R pterygoid
Why does TMJ dislocation happen?
mandibular head slides out of TMJ past the articular tubercle
- happens in yawning, taking large bites,
excessive contraction of lateral pterygoids
What are the consequences of aging on the mandible?
- loss of teeth and alveolar process is resorbed
- mental nerve more exposed due to mental and mandibular foramina being more superior on body of mandible
- body of mandible may fracture
What is the primary sympathetic effect on the pupils?
- dilate: slower effect
What is the primary sympathetic effect on the skin?
- contracts arrector pilli muscle (goosebumps)
- vasoconstriction
- sweating
What is the primary sympathetic effect on the glands of the head?
- no direct effect, but vasoconstriction has some indirect effect to reduce secretion
What is the parasympathetic effect on the eyes?
- pupil: constricts; fast effect
- ciliary body: lens accommodation
What is the parasympathetic effect on the skin?
no effect
What is the parasympathetic effect on the glands of the head?
- lacrimal: promotes secretion; tears
- salivary: promotes secretion; spit
- small mucous glands: promotes secretion; mucous i.e. snot
What are the dorsal cervical rami nerves of the cervical plexus?
- suboccipital
- greater occipital
- 3rd occipital
What are the spinal level and function of the suboccipital nerve?
- C1
- sensory, post gang sympathetic (gray ramus) innervation to semispinalis capitis and suboccipital muscles
What is the spinal level and function of the greater occipital nerve?
- medial branch C2
- sensory and postgang symp (gray ramus) innervation of skin overlying back of the head
What is the spinal level and function of the 3rd occipital nerve?
- median branch C3
- sensory and postgang symp (gray ramus) innervation of skin overlying suboccipital triangle
What are the ventral rami cutaneous nerves of the cervical plexus?
- lesser occipital
- great auricular
- transverse cervical
- supraclavicular
What is the spinal level and function of the lesser occipital nerve?
- C2
- sensory and postgang symp (gray ramus) innervation of the skin overlying the posterior- lateral aspect of the head and upper neck
What is the spinal level and function of the great auricular nerve?
- C2,3
- sensory and postganglionic symp (gray rami communicans) innervation of the skin overlying the upper sternocleidomastoid, lower parotid region and ear
What is the spinal level and function of the transverse cervical nerve?
- C2,3
- sensory and postganglionic symp (gray rami communicans) innevervation of the skin overlying the lower sternocleidomastoid and anterior neck
What is the spinal level and function of the supraclavicular nerve?
- C3,4
- sensory and postgang symp (gray rami communicans) innervation of the skin overlying the lower half of the posterior triangle of the neck
What are the muscular branch nerves of the ventral rami of the cervical plexus?
- nerve to geniohyoid
- nerve to thyrohyoid
- ansa cervicalis
- phrenic nerve
What is the spinal level and function of the nerve to geniohyoid?
- C1 via CN XII
- sensory, postganglionic symp (gray ramus), and motor innervation of the geniohyoid muscle
What is the spinal level and function of the nerve to thyrohyoid?
- C1 via CN XII
- sensory, postanglionic symp (gray ramus, and motor innervation of the thyrohyoid
What is the spinal level and function of the superior root of ansa cervicalis?
- C1
- sensory, postgang symp (gray ramus), and motor innervation of the superior belly of the omohyoid
What is the spinal level and function of the inferior root of ansa cervicalis?
- C2,3
- sensory, postgang symp (gray rami communicans), and motor innervation of the sternohyoid, sternothyroid, and inferior belly of the omohyoid muscles
What is the spinal level and function of the phrenic nerve?
- C3,4,5
- sensory, postganglionic symp (gray rami communicans), and motor innervation of the diaphragm
What are the strictly sensory nerves of the cervical plexus?
- greater occipital
- lesser occipital
- great auricular
- 3rd occipital
- transverse cervical
- supraclavicular
What are the sensory and motor nerves of the cervical plexus?
- suboccipital
- nerve to geniohyoid
- nerve to thyrohyoid
- ansa cervicalis (S+I omohyoid, sternohyoid, sternothyroid)
- phrenic nerve
