Unit 3: The neck and face Flashcards
Submental subdivision of anterior triangle
body of hyoid, anterior belly or digastric, mandibular symphysis, includes suprahyoid muscles, lymph nodes and mylohyoid, origin of anterior jugular
Submandibular subdivision of anterior triangle
inferior mandible, anterior and posterior digastric, conains submandibular gland, portion of hypoglossal nerve, facial artery and vein, and suprahyoid muscles
Carotid subdivision of anterior triangle
Superior belly of omohyoid, anterior SCM, posterior belly of digastric, contains common carotid, internal jugular, vagus, carotid body and sinus
Muscular subdivision of anterior triangle
midline of neck, superior belly of omohyoid, anterior SCM, contains infrahyoid muscles, parathyroid glands
Mylohyoid
N: mylohyoid A elevates hyoid, floor of mouth and tongue during swallowing and speaking
Stylohyoid
N: stylohyoid branch of facial nerve A elevate and retract hyoid
Geniohyoid
N: C1 of hypoglossal A: pulls hyoid anerosuperioly, shorten floor of mouth, widens pharynx
Digastric
N: (anterior) mylohyoid, (posterior) digastric branch of facial A: elevate and steady hyoid, depresses mandible against resistance
Innervation of the face
CN V trigeminal: sensory, motor for muscles of mastication; CN VII facial: motor
First branch of trigeminal
Opthalmic V1: purely sensory; supra-orbital, supratrochlear, infratrochlear: innervates scalp, forehead and lacrimal glands*
Second branch of trigeminal
Maxillary V2; infraorbital (teeth, eyelid, top lip), zygomaticotemporal (temple), zygomaticofacial (skin on cheek)
Third branch of trigeminal
Mandibular V3; sensory and motor: mental (skin of lip and chin), buccal (cheek, gums), auriculotemporal (ear)
Bell’s Palsy
loss of innervation of facial muscles; loss of facial tone and expression
Occipitofrontalis
Front belly (elevates eyebrows and wrinkles skin of forehead), occipital belly (retracts scalp, synergist to front), obicularis oculi (closes eyelid; palpebral and orbital parts)
Levator labii superioris
part of dilator of mouth, elevate upper lip, show sadness
Buccinator
presses cheek against molars, keeps food in cheek, resists detension
Zygomaticus major
dilator of mouth; elevate labial commissure (smile and sneer)
Levator anguli oris
part of dilator, widens oral fissure (gin/grimace)
Risorius
dilator, depresses labial (sadness)
depressor anguli oris
dilator, depresses labial (sadness)
depressor labii inferioris
dilator, retracts or everts lower lip (sadness)
Mentalis
elevates and protrudes lower lip, elevates skin of chin (doubt)
Facial nerve
CN VII: posterior auricular-occupitalis, temporal, zygomatic, buccal, marginal mandibular, cervical
Posterior auricular supplies
occupitalis
temporal supplies
O. oculi and inferior muscle
Buccal supplies
buccinator and O oris
marginal mandibular supplies
risorius and chin muscles
cervical supplies
platysma
Cutaneous scalp nerves
greater occipital and lesser occipital (C2)
Blood supply
mostly external carotid: facial, superficial temporal, and occipital; some internal carotid
Facial
Along inferior mandible deep to platysma, crosses inferior border anterior to masseter, mandible, buccinator, maxilla to canthus, superior and inferior labial branch
Superficial temporal
formed at TMJ joint between TMJ and auricle, produced the transverse facial almost immediately, supplies parotid gland and masseter, divides into frontal and parietal branch in scalp
Occipital
courses inferiorly under auricle through posterior triangle, emerges at back of head to supply scalp and occipitalis
Internal carotid
supplies superficial face via supratrochlear and supra orbital arteries
SCALP
Skin, connective tissue, aponeurosis, loose CT, periosteium; arteries within CT, held tightly, will bleed profusely, infection transmitted easily
Veins of head and neck
most with arteries, abundant anastomoses, drain to external or internal jugular via facial vein
