Head and Neck

neurocranium

calvarium- frontal, occipital, and parietal

cervical plexus: accessory nerve

trapezius and SCM

cervical plexus: hypoglossal nerve

tongue muscles

cervical plexus: lesser occipital nerve

sides of posterior scalp and outer ear

cervical plexus: greater auricular nerve

skin of the ear, mastoid process, and parotid gland

Ansa cervicalis

motor to infrahyoid muscles, move larynx and hyoid

cervical plexus: transverse cervical

skin of anterior and lateral neck

cervical plexus: supraclavicular nerves

skin over clavicle, anteromedial shoulder, proximal chest

cervical plexus: phrenic nerves

motor innervation to diaphragm

base

frontal, occipital, temporal, ethmoid, sphenoid

cranial fossae

brain case; contains and protects brain

• complex and varying depths

• openings for cranial nerves, blood vessels, spinal cord

• anterior cranial fossa, middle CF, posterior CF

foramen magnum

spinal cord passes through

foramen rotundum

maxillary nerve, maxillary artery, and emissary veins pass through

foramen ovale

mandibular nerve, accessory meningeal artery, lesser superficial petrosal nerve, and emissary veins pass through

external auditory meatus

connects outer ear to eardrum (ear canal)

stylomastoid foramen

in temporal bone between styloid and mastoid processes; facial nerve and styloid-mastoid artery pass through

supraorbital foramen

lateral branch of the supraorbital nerve passes through

infraorbital foramen

infraorbital nerve and vessels to the face pass through

• division of trigeminal nerve

mental foramen

mental nerve passes through

• key landmark for dental and facial surgeries

viscerocranium

skeleton part of the phase; 14 bones

zygomatic

lacrimal

nasal

inferior nasal concha

maxilla

palatine

vomer

mandible

sagittal suture

coronal sutures

lambdoid suture

squamous suture

metopic suture

mandibular condyle

coronoid process

body of mandible

contains lower teeth sockets

base of mandible

sharp inferior edge of body (jawline)

submandibular fossa

interior aspect of mandible; submandibular gland rests here

temporomandibular joint

where the mandibular process joins with the temporal bone

hyoid

U-shaped; serves as an attachment for muscles involved in speech and swallowing

Larynx

formed by arytenoid, corniculate, and cuneiform cartilage (paired) and thyroid, cricoid, epiglottic cartilage (unpaired)

cervical spine

most mobile segment of spinal column

• upper cervical spine- interface between skull and spinal column

  • C1- atlas

  • C2- axis

• lower cervical spine- C3-C7

• nuchal ligament- extends inferiorly from external occipital protuberance to cervical spine; holds areas together

Axis

C2; uniquely designed with DENS- projects upward into atlas

• allows for rotation of the skull

atlantooccipital joint

interface between skull and vertebral column

• yes joint- flexion and extension of head

• convex occipital condyle and conclave atlas facet

atlantoaxial joint

most mobile portion formed by odontoid process

• pivot for rotation

• no joint

Muscles of Facial Expression

attach to underlying fascia and face to express emotion

Mneumonic- Beavers Don’t Date Llamas, LLamas Make Overly Picky Roomates

Muscles of mastication and speech

movement of the mandible

Muscles of Swallowing

voluntary and involuntary muscle contractions, phases of swallowing, movements of tongue

Muscles for eye movement

extraocular muscles that move eyes and elevate eyelid

Buccinator muscle

facial expression- contracts cheek, narrows mouth

• kiss

depressor anguli oris

facial expression- pulls corners of mouth down

• frown

depressor labii inferioris

facial expression- depresses, protrudes and pulls the lips

levator anguli oris

facial expression- elevates angles of the mouth

levator labii superioris

facial expresion- elevates and protrudes upper lip

mentalis

facial expression- elevated median skin of chin

orbicularis oris

closes and shapes the lips

platysma

facial expression- tightens the neck

risorus

facial expression- retracts corners of mouth

zygomaticus major

pulls up the corners of the mouth

zygomaticus minor

elevates and protrudes upper lip

levator labii superioris alaeque nasi

flares nostrils

nasalis

controls and regulates airflow

procerus

pulls skin between eyebrows together

corrugator supercilia

depresses and pulls eyebrow medially

orbicularis oculi

closes eyelid

occipitofrontalis

elevates both eyelids

auricularis

wiggles ears

masseter

elevates and protrudes mandible for speech and chewing

• bite force of up to 150 lbs

temporalis

elevates and retracts mandible for speech and chewing

medial and lateral pterygoids

protrude mandible; laterally and medially deviate to grind food

extrinsic tongue muscles

protrude, retract, depress, and elevate the sides of the tongue to assist with swallowing

intrinsic tongue muscles

elevate and depress the tip of the tongue; flatten, widen, narrow, and protrude the tongue

suprahyoids

elevate hyoid and tongue, depresses mandible

digastric

depresses mandible, elevate hyoid, retract mandible

infrahyoid

depress hyoid and thyroid cartilage

levator palpebrae

elevates eyelid

extraocular mucles

move eye up, down, lateral, and medial to scan environment

• superior rectus, medial rectus, lateral rectus, inferior rectus, superior oblique, inferior oblique

Movement of Temperomandibular Joint

elevates, depresses, protracts, retracts

• essential for speech, feeding, swallowing

• synovial joint

muscles of the neck

around 30 muscles that extend from the base of the skull and jaw to the shoulder blades and collar bones

• support and move head, neck, and spine

• chewing, swallowing, breathing

Anterior muscles of the neck

superficial, suprahyoid, infrahyoid, scalene

posterior muscles of the neck

superficial, suboccipital, transversospinalis

Neck flexion

sternocleidomastoid, anterior scalens, longus capitis, longus colli

neck extension

trapezius, levator scapulae, splenius capitus, splenius cervicis, rectus capitis posterior major/minor, oblique capitis superior, semispinalis capitis

ipsilateral rotation

levator scapulae, splenius capitis, spenius cervicis, rectus capiris posterior major, oblique capitis interior, longus colli, longus capti

contralateral rotation

trapezius (upper fibers), sternocleidomastoid, anterior/middle/posterior scalene, mutifidi, rotatores

lateral flexion

trapezius (upper fibers), sternocleidomastoid, levator scapulae, scalenes, splenius capitis, splenius cervicus, longus capitis, longus coli

Trigeminal Nerve (CN 5)

ophthalmic branch- supplies forehead, scalp, frontal, ethmoid and sphenoid sinuses, epper eyelid and conjunctiva, cornea, dorsum of nose, and lacrimal gland

maxillary branch- supplies lower eyelid, conjunctiva, cheeks, maxillary sinus, lateral nose, upper lip, teeth, and superior palate

mandibular branch- supplies lower 1/3 of face, lower teeth, anterior 2/3 of tongue, chewing

review cranial nerves

Oh Oh Oh To Touch And Feel Very Good Velvet Ah Heaven

Some Say Money Matters But My Brother Says Big Brains Matter Most

Major nerves of neck

C1-C7- exit superior to corresponding vertebra

C8- emerges inferior to C7

cervical plexus- C1-C4

memorize cervical plexus

Arteries of head and neck

internal and external carotid arteries, vertebral arteries, thyrocervical trunk

veins of head and neck

fascial vein, inferior/middle/superior thyroid veins, jugular veins, vertebral veins

Functions of Face

• communication (verbal and non-verbal)

• feeding, eating, swallowing

• vision

• reaching

• listening

• posture

Infant and Early Childhood

• large head compared to rest of their body

• paraspinal cervical muscles are relatively weak at birth

• head lag should be absent by 3-4 months

• full control by 6 months

• face has to catch up to head size; growth is significant during this stage

• adenoids and tonsils are largest in relation to surrounding structures between 4-6 years

Adolescence/Puberty

• female facial maturation- 12-15 years

• male facial maturation- 15-18 years

• airway length increases significantly in boys after puberty

• males experience enlarged vocal cords—> deep voice

• facial fat and overall body fat change

Adult

• neck muscles weaken

• fat distribution shifts

• reduced collagen and elastin production—> thinning and sagging skin

• loss of bone mass in haw; reduced lower face size

• nose and ears appear to lengthen

• eyes change with wrinkles, sunken appearance, drooping eyelids

• swallowing changes- decreases sensitivity, weakened muscles

• hunch back