lecture 26-facial vessels and nerves

C4

at what level does the common carotid a bifurcate?

carotid canal

the internal carotid a continues upwards to the skull, passing through the ___ without giving rise to any branches

neck, posterior skull, and face

the external carotid a gives rise to several branches that supply structures in the...

facial a

what is the primary a that supplies the superficial facial structures?

superior thyroid a, lingual a, facial a, ascending pharyngeal a

what branches of the external carotid a arise within the carotid triangle?

superior thyroid a, lingual a, facial a

what branches arise from the anterior aspect of the external carotid a?

ascending pharyngeal a

what branch of the external carotid a arises from the medial aspect?

occipital and posterior auricular aa

what branches of the external carotid a arise at the level of the posterior belly of the digastric m?

superficial temporal and maxillary aa

what are the terminal branches of the external carotid a whose origin begins posterior to the neck of the mandible?

superior thyroid a, lingual a, facial a, maxillary a, superficial temporal a, posterior auricular a, occipital a, ascending pharyngeal a

list branches of external carotid a

inferior border of mandible deep to platysma

what does the facial a hook around?

anterior border of masseter m

where can a pulse for the facial a be palpated?

body of mandible, buccinator m, and maxilla

the facial a courses toward the medial angle of the eye by crossing what?

zygomaticus major and levator labii superioris mm

what does the facial a lie deep to?

angular a

where the facial a ascends along the side of the nose to the medial angle of the eye is called what?

lateral nasal a, superior labial a, inferior labial a

what are the branches of the facial a?

ramus of the mandible

when the external carotid a continues to ascend the lateral surface of the face, it runs posterior to the...

larger of the two terminal branches, courses anteriorly to supply deeper structures of the face

describe the maxillary a

smaller of the two terminal branches and courses superiorly between the TMJ and auricle

describe the superficial temporal a

as it bifurcates into frontal and parietal branches

how does the superficial temporal a terminate?

scalp

the frontal and parietal branches of the superficial temporal a supply what?

auriculotemporal n

the frontal and parietal branches of the superficial temporal a course in proximity to what?

approximately 1.5cm below the zygomatic arch

where does the transverse facial a arise from the superficial temporal a?

traverses anteriorly across the face superficial to the masseter m

how does the transverse facial a run?

branches of facial a

what does the transverse facial a form an anastomosis w?

occipital and posterior auricular aa (p)

what aa arise from the posterior aspect of the external carotid a and supply the scalp?

dense connective tissue layer (layer 2)

the superficial aa to the scalp form anastomoses and are all contained within what layer of the scalp?

CN V1 (st)

what is the n for the supratrochlear n?

CN V1 (so)

what is the n for the supraorbital n?

CN V2 (z)

what is the n for the zygomaticotemporal n?

CN V3

what is the n for the auriculotemporal n?

C2, C3

what is the n for lesser occipital n?

C2

what is the n for the great occipital n?

C3

what is the n for the third occipital n?

facial v

what provides the major venous drainage of the face?

true

true or false: the facial v runs with the facial a but has a more direct course

valveless veins

unlike most medium sized veins, the facial vv are...

supratrochlear and supraorbital vv

what vv unite near the medial corner of the eye to form the angular v?

deep facial v

the angular v unites with what v to form the facial v?

lies deep to zygomaticus major m but superficial to the levator labii superioris m

how is the course of the facial v the same and different from the facial a?

inferior to neck of mandible

where is the retromandibular v formed?

superficial temporal v and maxillary v

the retromandibular v is formed by the union of what vv?

anterior and posterior branch

what does the retromandibular v divide into?

posterior auricular v to form external jugular v

what does the posterior branch of the retromandibular v combine with?

internal jugular v

what does the common facial v drain into?

common facial v

the anterior branch of the retromandibular v joins the facial v as it approximates the angle of the mandible to form the...

danger triangle

what does the area between the corners of the mouth and bridge of the nose form?

facial v is valveless so it is possible for infection in this area to move in retrograde fashion and carry infection to cavernous sinus

why does the danger zone exist?

ophthalmic vv

an infection from the danger triangle could be carried to the cavernous sinus via what vv?

infection within the cranium or cavernous sinus thrombosis

infection that spreads to the cavernous sinus increases the risk of...

trigeminal n (CN V)

what is the largest cranial n?

lateral surface of pons

where does the trigeminal n originate from?

mixed with sensory and motor roots

what is the composition of the trigeminal n?

face, anterior portion of scalp, paranasal sinuses, teeth, mouth, and nasal cavity

what does the trigeminal n carry sensory information from?

mm of mastication

what does the trigeminal n supply motor innervation to?

ophthalmic (V1), maxillary (V2), and mandibular (V3)

what are the three divisions of the trigeminal n?

travels through the orbit to supply the skin of the forehead, eyes, and nose

describe ophthalmic division (V1) of trigeminal n

travels through the maxilla and zygoma to supply the skin of the cheeks

describe maxillary division (V2) of trigeminal n

supplies the skin of the lower face or mandibular region and muscles of mastication

describe mandibular division (V3) of trigeminal n

sensory root is large, motor root is much smaller

how does the size of the sensory and motor roots of the trigeminal n compare?

all three

what divisions of the trigeminal n have a sensory component?

trigeminal ganglion

where are the cell bodies of the sensory neurons of the trigeminal n located?

mandibular division of trigeminal n (CN V3)

what does the motor root of the trigeminal n contribute to?

cranial vault

the divisions of the trigeminal n leave the ___ through different foramina or openings in the sphenoid bone

ophthalmic division (V1)

what division of the trigeminal n is the smallest and is purely sensory?

superior orbital fissure

what does the ophthalmic division (V1) of the trigeminal n travel through?

purely sensory, travels through foramen rotundum

describe maxillary division of trigeminal n (V2)

largest, travels through foramen ovale

describe the mandibular division of trigeminal n (V3)

the sensory and motor roots unite

what happens to the mandibular division as it passes through the foramen ovale?

frontal n, lacrimal n, nasociliary n

what branches does the ophthalmic division (V1) give rise to?

skin of forehead

what does the frontal n innervate?

conjunctiva and upper eyelid

what does the lacrimal n innervate?

CN VII, lacrimal gland

the lacrimal n transmits secretomotor (parasympathetic) fibers to control lacrimation from ___ to ____

skin of dorsum of nose and bridge of nose, conjunctiva, and sinuses

what does the nasociliary n innervate?

skin of forehead, dorsum of nose, upper eyelid, conjunctiva, eye, mucosa of frontal and ethmoid sinuses

what does the ophthalmic division V1 provide general sensation for?

skin of inferior eyelid and cheek, teeth and palate, mucosa of upper jaw and nasal cavity, nasopharynx, maxillary sinuses

the maxillary division (V2) has a number of branches which innervate...

skin of lower jaw, mucosa of lower jaw, teeth, skin of anterior auricle

the mandibular division (V3) provides general sensation to...

mm of mastication, tensor veli palatini m, tensor tympani m, mylohyoid m, anterior belly of digastric m

what does the mandibular division (V3) provide motor innervation to?

trigeminal neuralgia

what is tic doulereux aka?

MS, post-herpetic neuropathies (ex: shingles affecting trigeminal n)

inflammation of the trigeminal n may occur in conditions such as...

bouts of sharp, stabbing, electric shock-like shooting or burning pain that may last for seconds to minutes and may recur repeatedly throughout the day

what do pts with tic doulereux (trigeminal neuralgia) report?

worsen and become more resistant to meds

pts with trigeminal neuralgia may experience symptom free periods that last days to years, but over time, what happens to sx?

facial n (CN VII)

what is the sole motor supply to the mm of facial expression including scalp mm and superficial mm of neck (platysma)?

anterior 2/3 of tongue

the facial n is the sensory supply for the...

superficial aspect of parotid gland

the facial n emerges from the skull through the stylomastoid foramen and enters what?

lateral pontomedullary junction

where does the facial n (CN VII) originate from?

2: motor, sensory and parasympathetic

as the facial n leaves the brainstem, how many roots are there?

larger, supples mm of facial expression including platysma, occipitofrontalis, and auricular mm (based on common embryological origin)

describe motor root of facial n (CN VII)

smaller, carries preganglionic parasympathetic fibers, sensory info from middle ear and gustatory info from anterior 2/3 of tongue and hard palate

describe intermediate n of facial n (CN VII)

intermediate n

what is the sensory and parasympathetic root of facial n called?

greater petrosal n, pterygopalatine

at the geniculate ganglion, some preganglionic parasympathetic fibers of facial n will travel with the ___ n to the ___ ganglion

lacrimal n

at the geniculate ganglion, some preganglionic parasympathetic fibers of facial n will travel with the greater petrosal n to the pterygopalatine ganglion and synapse with postganglionic fibers that travel with the...

chorda tympani n

the facial n continues through the temporal bone and gives rise to what?

submandibular ganglion and tongue

the chorda tympani n carries remaining preganglionic parasympathetic fibers and sensory fibers via lingual nerve to what?

submandibular and sublingual salivary glands

when the chorda tympani n carries remaining preganglionic parasympathetic fibers and sensory fibers via lingual nerve to submandibular ganglion and tongue, what will the postganglionic fibers innervate?

extracranial portion

what portion of the facial n is primarily motor?

parotid gland

the extracranial portion of the facial nerve forms a plexus within the ___ which gives rise to 5 main branches

superiorly and anteriorly towards face and inferiorly towards neck

the five branches from the motor root of the facial n emanate from the parotid gland and course...

temporal, zygomatic, buccal, mandibular, cervical

what are the five main branches of the motor root of the facial n?

supraorbital and forehead mm

what does the temporal branch of the facial n supply?