Facial Vessels, Cutaneous Nerves, and Scalp

branches of external carotid artery

• facial artery

• superficial temporal artery

• infraorbital artery

• mental artery

branches of internal carotid artery

• supraorbital artery

• supratrochlear artery

main blood supply of face

facial artery

facial artery passes deep to

posterior belly of digastric m; travels through digastric triangle

antegonial notch

small concavity on inferior surface of body; anterior to mandibular angle where facial artery crosses onto face

key characteristics of facial artery

• crosses inferior border of mandible

• travels immediately anterior to masseter and facial vein

• tortuous

branches of facial artery

• inferior labial (supplies lower lip)

• superior labial (supplies upper lip)

• lateral nasal (supplies nostril)

facial artery terminates as

angular artery

superficial temporal artery

terminal branch of external carotid artery that emerges onto face between TMJ and external ear

transverse facial artery

branch off superficial temporal artery that supplements blood supply to lateral face

supraorbital and supratrochlear arteries provide

supplemental supply to forehead and scalp

supraorbital artery

• terminal branch of ophthalmic artery (from internal carotid artery)

• emerges from supraorbital foramen/notch

• supplies forehead and scalp

• more lateral

supratrochlear artery

• terminal branch of ophthalmic artery (from internal carotid artery)

• emerges from frontal notch

• supplies forehead and scalp

• more medial

infraorbital and mental arteries

indirect branches off maxillary artery (off external carotid artery)

infraorbital artery supplies

midface regions

mental artery supplies

chin regions

main drainage of face

facial vein

common facial vein is formed by

facial vein + anterior division of retromandibular vein

retromandibular vein is formed by

maxillary vein + superficial temporal vein

superior and inferior ophthalmic veins drain posteriorly into

cavernous sinus

cervical ventral rami of great auricular nerve

C2-C3

great auricular nerve

sensory; cutaneous branch of cervical plexus that innervates skin overlying angle of mandible

CN V (trigeminal nerve) emerges laterally from

pons

CN V (trigeminal nerve) has three major branches

• ophthalmic (V1) → superior orbital fissure

• maxillary (V2) → foramen rotundum

• mandibular (V3) → foramen ovale

large sensory root of CN V is composed mainly of

pseudounipolar neurons that comprise trigeminal ganglion

V1 splits into

• nasocilliary nerve

• frontal nerve

• lacrimal nerve

supraorbital and supertrochlear (indirect) branches of ophthalmic nerve (V1) reach

skin of forehead

supratrochlear nerve innervates

skin of medial forehead

supraorbital nerve innervates

skin of lateral forehead

supraorbital nerve emerges onto face via

supraorbital notch/foramen

supratrochlear nerve emerges onto face via

frontal notch

supraorbital notch/foramen is located

lateral to frontal notch

maxillary nerve (V2) reaches skin of face via

infraorbital, zygomaticotemporal, and zygomaticofacial nerves

zygomaticotemporal nerve emerges from

zygomaticotemporal foramen

zygomaticofacial nerve emerges from

zygomaticofacial foramen

infraorbital nerve emerges from

infraorbital foramen after giving off anterior and middle superior alveolar nerves

zygomaticofacial foramen

small hole in anterior/lateral part of zygomatic bone that empties onto face

zygomaticotemporal foramen

small hole in posterior part of zygomatic bone that empties onto temporal fossa

auriculotemporal nerve innervates

TMJ, external acoustic meatus, and skin anterior to ear

auriculotemporal, long buccal, and mental branches of mandibular nerve (V3) innervate

skin anterior to ear, cheek, and chin regions

long buccal nerve appears

on external surface of buccinator m; on internal surface of masseter m

mental nerve is continuation of

inferior alveolar nerve after it has exited mandible via mental foramen

auriculotemporal nerve travels alongside

superficial temporal vessels

long buccal nerve innervates

skin superficial to buccinator and oral mucosa internally

long buccal nerve pierces

buccinator muscle

long buccal nerve emerges onto face from

region of infratemporal fossa

mental foramen transmits

mental nerve, artery, and vein to skin of chin and lower lip

herpes zoster (shingles) is produced by

reactivation of latent virus in trigeminal ganglia

trigeminal neuralgia

neurologic condition characterized by episodes of brief, intense facial pain over one of three areas of distribution of CN V (V2 > V3> V1)

presentation of trigeminal neuralgia

• physical jerk

• sudden immobility

• involuntary facial twitches

• sudden shout of pain

causes of trigeminal neuralgia

• stress

• nerve damage

• nerve compression

• nerve demyelination

• trauma

5 layers of scalp

• skin

• connective tissue (dense)

• aponeurotic layer (galea aponeurotica)

• loose connective tissue

• pericranium

connective tissue (dense), or tela subcutanea

• anchors skin to aponeurotic layer of scalp

• contains nerves, arteries, and veins of scalp

scalp wounds bleed profusely due to

extensive anastomoses of blood vessels in dense connective tissue

blood supply to scalp is provided by

internal and external carotid arteries

innervation to scalp is provided by

cranial and spinal nerves

aponeurotic layer (galea aponeurotica)

• tendinous sheet that covers calvaria

• attachment site for occipitofrontalis m

if epicranial aponeurosis is cut in coronal plane

scalp gapes due to pull of frontal and occipital bellies of occipitofrontalis m

loose connective tissue

• facilitates movement of uppermost three layers of scalp over calvaria

• dangerous zone because pus and blood can spread easily within this layer and spread into cranial cavity via emissary veins

pericranium

dense CT that forms periosteum on outer surface of calvaria