Anatomy Study Guide Head and Neck pdf - Dr.Maan

ANATOMY EXAM 3 STUDY GUIDE – HEAD & NECK

CRANIAL NERVES

Name

Origin

Foramen

Fibers

Branches

Functions

Olfactory

CNS ectoderm

Cribiform plate
(ethmoid bone)

Sensory

Transmit olfaction to brain

Optic

Diencephalon

Optic canal

Sensory

Transmit visual info to brain

III

Oculomotor

Mesencephalon

Superior orbital

fissure

Motor

GSE

GVE

GSE – motor innervation to all

but 2 extraocular muscles

GVE – pregang parasymp fibers

to ciliary ganglion cells

Trochlear

Metencephalon

or mes?

Superior orbital

fissure

Motor

GSE

Motor innerv to superior oblique

extraocular muscle

Trigeminal

Metencephalon

– Superior

orbital fissure

– foramen

rotundum

– foramen

ovale

Both

GSA

SVE

GVE

– ophthalmic

– maxillary

– mandibular

GSA – extero and proprioceptive

sensory nerve of face and anterior

head (Great somatic sensory

nerve)

SVE – motor innerv to striated

muscles of mastication

Abducens

Metencephalon

Superior orbital

fissure

Motor

GSE

Motor innerv to lateral rectus

extraocular muscle

VII

Facial

Metencephalon

Internal

acoustic meatus

(for all

branches)

Both
SVE

GVE

GSA

GVA

Temporal

Zygomatic

Buccal

Mandibular

Cervical

SVE – striated muscles that

originated from branchial arch 2

for facial expression

GVE – pregang parasymp fibers

to pterygopalatine and

submandibular ganglia cells

SA – taste buds of palate and

anterior tongue

GSA – exteroceptive sensation

from skin behind ear, in floor of

external auditory meatus, outer

surface of eardrum

GVA – interoceptive from nasal

cavity mucosa, oral cavity and

palate; glands controlled by

pterygopalatine and

submandibular glands

VIII

Vestibulocochlear

Metencephalon

Internal

acoustic meatus

Sensory

From sensory hair cells of

vestibular labyrinth for balance

and hearing

Glossopharyngeal

Myencephalon

Jugular foramen

Both

GVA

GVE

SVE

GSA

GVA – from posterior tongue

(glossus) and pharynx,

auditory/Eustachian tube, middle

ear, inner eardrum surface

GVE – pregang parasymp fibers

innervating otic ganglia

SA – fibers from taste buds of

vallate papillae and posterior

tongue

SVE – stylopharyngeus striated

muscle of 3

branchial arch

GSA – exteroceptive sensation

from same skin patch supplied by

facial nerve

Vagus

Myencephalon

Jugular foramen

Both

GVE

GVA

GVE – pregang in parasymp

motor path to glands of epiglottis

and to cervical, thoracic, ab

SVE

GSA

viscera

GVA – interoceptive info carried

as afferent limb of visceral

reflexes (poor sensation of pain,

temp, touch, pressure in larynx

and upper esoph lining)

SVE – motor innerv to striated

muscle of palate, larynx, pharynx,

upper esoph; from 4

and 6

branchial arches

SA – from taste buds at base of

tongue, around epiglottis, in

upper larynx

GSA – exteroceptive fibers from
skin patch supplied by facial and

glossopharyngeal and

proprioceptive fibers from

laryngeal muscles

Accessory

Cervical spine

Jugular foramen

Motor

SVE

Cranial and spinal roots that

converge at jugular foramen and

diverge outside of skull; cranial

nerve becomes accessory of

vagus and spinal root supplies

motor fibers to trapezius and

sternocleidomastoid

XII

Hypoglossal

Myencephalon

Hypoglossal

Motor

GSE

GSA

GSE – intrinsic and extrinsic

tongue muscles (excl.

palatoglossus which gets SVE

from CN X and XI); goes to

glossus from below

GSA (and GSE) – supply

geniohyoid and thyrohyoid

muscles

C1 fiber – leaves hypglossal as

uperior limb of ansa cervicalis

and enters infrahyoid in anterior

triangle

MUSCLES (53)

Grouping

Muscle

Action

Innervation

Vasculature

Face (9)

Buccinator

Presses cheek against molar

teeth

Resists detention

Buccal branch of CN VII

Facial a.

Orbicularis oculi

Closing eyelids (squinting)

Facial nerve (CN VII)

Supraorbital a.

Supratrochlear a.

Infraorbital a.

Angular branch of

facial a.

Depressor labii inferioris

Depresses lower lip

Inferior labial

branch of facial a.

Mental a.

Zygomaticus major

Draws angle of mouth

backward and upward (smile)

Transverse facial

Facial a.

Zygomaticus minor

Elevates upper lip

Transverse facial

Facial a.

Orbicularis oris

Closes lips; kissing muscle

Superior &

inferior labial

branches of facial

Mental a.

Infraorbital a.

Levator labii superioris

Elevates upper lip

Dilates nares (disgust)

Infraorbital a.

Superior labial

branch of facial a.

Depressor anguli oris

Depresses angle of mouth

Inferior labial

branch of facial a.

Mental a.

Levator anguli oris

Elevates angle of mouth

medially (disgust)

Infraorbital a.

Superior labial

branch of facial a.

Neck (1)

Digastric

Elevates hyoid and floor of

mouth

Depresses mandible

Anterior belly –

mylohyoid n. of V

(CN

Posterior belly – facial n.

Anterior belly –

submental a.

Posterior belly –

occipital a.

Neck (3)

Posterior Triangle

Platysma

Tenses skin of inferior face

Depresses jaw

Facial nerve

Facial a.

Subclavius

Depresses clavicle

N. to subclavius

Thoracoacromial

a.-clavicular

branch

Omohyoid

Depresses/stabilizes hyoid bone

Ansa cervicalis

Transverse

cervical a.

Neck (4)

Muscular Triangle

Infrahyoid muscles

Sternohyoid

Superior thyroid a.

Sternothyroid

Superior belly of

omohyoid

Transverse

cervical a.

Thyrohyoid

Elevates larynx

Depresses/stabilizes hyoid bone

Superior thyroid a.

Neck (2)

Carotid Triangle

Cricothyroid

Draws thyroid cartilage

forward, lengthening vocal

ligaments

External branch of

superior laryngeal n.

(branch of vagus n.)

Cricothyroid

branch of superior

thyroid a.

Thyrohyoid (also in

muscular triangle)

See above

Neck (3)

Submandibular

Digastric (ant and post

bellies)

See above

(digastric) Triangle

Mylohyoid

Elevates hyoid bone and tongue

when speaking and swallowing

N. to mylohyoid (branch

of inferior alveolar n.

from V

)

Mylohyoid branch

of inferior alveolar

Stylohyoid

Elevates and retracts hyoid

bone

Facial n. (CN VII)

Ascending

pharyngeal a.

Neck (2)

Submental Triangle

Digastric muscles (sides)

See above

Mylohyoid (floor)

See above

Neck (5)

Structures deep to

floor of triangle

Levator scapulae

Elevates scapula

Dorsal scapular n. (C5)

Dorsal scapular a.

Splenius capitus

Extends, laterally bends neck

and head

Rotates head to same side

Dorsal primary rami of

spinal n.

Deep cervical a.

Scalenes (3)

(posterior, middle,

anterior)

Anterior & Middle – elevates

first rib; flexes and laterally

bends neck

Posterior – elevates second rib;

flexes and laterally bends the

neck

Anterior – brachial

plexus (C5-C7)

Posterior – brachial

plexus (C7-C8)

Middle – brachial plexus

(C3-C8)

Ascending

cervical a. (branch

of thyrocervical

trunk)

Neck (1)

Geniohyoid

C1 and C2 coursing with

hypoglossal n. (CN XII)

Linguial a.

Submental a.

Head/Mastication

(4)

Temporalis

Elevates and retracts mandible

Deep temporal n.

Anterior &

posterior deep

temporal arteries

Lateral pterygoid

Protracts and depresses the

mandible

Moves mandible laterally

N. to lateral pterygoid

Pterygoid branch

of maxillary a.

Medial pterygoid

Elevates and protracts mandible

Moves mandible laterally

N. medial pterygoid

Masseter

Elevates mandible, closes jaw

Anterior trunk of CN V

(masseteric n)

Masseteric branch

of maxillary a.

Pharynx (4)

Middle pharyngeal

constrictor

Constricts walls of pharynx

during swallowing

Pharyngeal branch of

Vagus and Pharyngeal

plexus

Ascending

pharyngeal a.

Superior pharyngeal

constrictor

Inferior pharyngeal

constrictor

Ascending

pharyngeal a.

Superior thyroid a.

Inferior thyroid a.

Stylopharyngeus

Elevates and dilates pharynx

during swallowing and

speaking

Glossopharyngeal n.

(CN IX)

Ascending

pharyngeal a.

Extraocular

muscles of the

Orbit (7)

Levator palpebrae

superioris

Elevates superior eyelid

Oculomotor n. (CN III)

Superior rectus

Elevates, ADducts and

medially rotates eyeball

Medial rectus

ADducts eyeball

Inferior rectus

Depresses, ADducts and

medially rotates eyeball

Inferior oblique

ABducts, elevates and laterally

rotates eyeball

Superior oblique

ABducts, depresses and
medially rotates eyeball

Trochlear n. (CN IV)

Lateral rectus

ABducts eyeball

Abducent n. (CN V)

Extrinsic muscles

of the tongue (4)

Palatoglossus

Elevates posterior tongue,

depresses soft palate, contricts

isthmus of fauces

Pharyngeal branch of

vagus n. (CN X)

Genioglossus

Depresses tongue, posterior

fibers protrude tongue

Hypoglossal n. (CN XII)

Sublingual a.?

Hyoglossus

Depresses and retracts tongue

Dorsal lingual a.?

Styloglossus

Retracts and elevates tongue,

aids initiation of swallowing

Intrinsic muscles of

the tongue (4)

Superior longitudinal

Curls tongue upward, retrudes

tongue

Deep lingual a. ?

Inferior longitudinal

Curls tongue downward,

retrudes tongue

Transverse

Narrows and protrudes tongue

Vertical

Flattens and broadens tongue

Chin (1)

Mentalis

Elevates and wrinkles skin of

chin and protrudes lower lip

Mandibular branch of

facial nerve

Arytenoids (5)

Thyroarytenoid

Relaxes vocal ligament

Inferior laryngeal nerve

(terminal part of

recurrent laryngeal
nerve, from CN X)

Posterior cricoarytenoid

Abducts vocal folds

Lateral cricoarytenoid

Adducts vocal folds

Transverse & oblique

arytenoids

Adducts arytenoids cartilages

(adducting intercartilagenous

portion of vocal folds, closing

posterior rima glottides)

Vocalis

Relaxes posterior vocal

ligament while maintaining (or

increasing) tension of anterior

part

MNEMONICS/STUDY TIPS

LAB 1: TRIANGLES & ROOT OF NECK
Mnemonic – Carotid sheath contents:

I see 10 CCs

in the

I see =

nternal

arotid artery

10 = CN

(vagus nerve) (posterior)

CC =

ommon

arotid artery (medial)

IV =

nternal Jugular

ein (lateral)

Relations of important nerves and vessels to the anterior scalene muscle

Structures passing anterior to anterior scalene

o  Vagus n.
o  Phrenic n.
o  Thyrocervical trunk branches
o  Subclavian v.

Structures passing posterior to anterior scalene

o Brachial plexus
o Subclavian a.

LAB 2: FACE, SCALP, & PAROTID REGION
Mnemonic – Motor branches of the facial nerve (CN VII):

anzibar

otor

ar OR

ebras

occyx

emporal

ygomatic

uccal

arginal mandibular

ervical

Mnemonic – Scalp nerve supply:

GLASS

reater occipital/Great auricular

esser occipital

uriculotemporal

upratrochlear

upraorbital

Scalp blood supply

External carotid artery branches

o  Occipital
o  Posterior auricular
o  Superficial temporal

Internal carotid artery branches

o Supraorbital
o Supratrochlear

Mnemonic – Innervation of muscles

acial nerve innervates muscles of

facial

expression

andibular nerve innervates muscles of

mastication

Mnemonic – External carotid artery branches (in ascending order):

ome

ngry

ady

igured

PMS

uperior thyroid

scending pharyngeal

ingual

acial

ccipital

osterior auricular

axillary

uperficial temporal

Mnemonic – Scalp Layers:

SCALP

kin

onnective tissue

poneurosis

oose areolar tissue

ericardium

LAB 3: CRANIAL CONTENTS, REFLECTION OF HEAD, PHARYNX

Epidural hematoma

Anterior branch of middle meningeal artery (MMA) courses superiorly to cross pterion

Trauma to side of head may cause fractures of bones forming the pterion and consequently rupture the MMA located in this
region

Since MMA course between dura and calvaria, in epidural space, hemorrhage in this location is called an epidural hematoma

Subdural hematoma

A blow to the head the jerks the brain inside the skull can cause the tearing of a cerebral vein, usually as it enters the superior
sagittal sinus

Since cerebral veins course between the dura and arachnoid maters, a hemorrhage in this location is called a subdural
hematoma

Clinical correlation – hematomas on CTs

Epidural hematomas: lens shape

Subural hematomas: crescent shape

Subarachnoid hematomas: conform to the shape of sulci

Arachnoid granulations

Projections of subarachnoid space that serve to return CSF to the venous system

On inner aspect of the calvaria you will notice small shallow depressions

The depressions are caused by the arachnoid granulations

Clinical correlation – Middle Meningeal artery

Its anterior branch crosses the area of the pterion

Fractures through this area result in tearing of the middle meningeal artery with consequence of an epidural hematoma

Mnemonic – foramen ovale contents:

OVALE

tic ganglion (just inferior)

ccessory meningeal artery

esser petrosal nerve

missary veins

Foramina in posterior cranial fossa: all structures pass through temporal or occipital bones

Internal auditory meatus – CN VII, VIII

Jugular foramen – CN IX, X, XI, jugular vein

Hypoglossal canal – CN XII

Foramen magnum – spinal roots of CN XI, brain stem, vertebral arteries

Cisterns

Name of areas where subarachnoid space is enlarged

Dural folds

Tentorium cerebelli – separates the cerebellar lobe from the corresponding occipital pole of the cerebral hemisphere

Falx cerebelli – projects between cerebellar hemispheres

Falx cerebri – separates the two cerebral hemispheres

Mnemonic – cranial nerves:

lympus’

owering

op,

ine

erman

aulted

opped

lfactory (I) – sensory

ptic (II) – sensory

culomotor (III) – motor

rochlear (IV) – motor

rigeminal (V) – both

bducent (VI) – motor

acial (VII) – both

estibulocochlear (VII) – sensory

lossopharyngeal (IX) – both

agus (X) – both

ccessory (XI) – motor

ypoglossal (XII) – motor

Mnemonic – cranial nerve modalities:

ome

arry

oney (or money matters)

rother

ays

rains

atter

ore

ensory

otor

oth

Circle of Willis arteries supply:

ACA (anterior cerebral a.) – medial surface of brain, leg-foot area of motor and sensory cortices

MCA (middle cerebral a.) – lateral aspect of brain, Broca’s and Wernicke’s speech areas

Ant. Communicating a. – most common Circle of Willis aneurysm, may cause visual field defects

Post. Communicating a. – common area of aneurysm, may cause

CN III palsy

Clinical correlation – signs of stroke

Stroke of anterior circle

– general sensory and motor dysfunction, aphasia

Stroke of posterior circle

– vertigo, ataxia, visual deficits, coma

Clinical correlation – pulsating exophthalmos

In fractures of the base of the skull, the ICA (internal carotid a?) may rupture within the cavernous sinus, forming an
arteriovenous fistula

This creates reflux of blood from the cavernous sinus into the ophthalmic veins, which normally drain the orbital cavity

As a result, eye will appear protruded, engorged, and will pulsate

Mnemonic – structures passing through cavernous sinus

CN III, IV, V

, and V

pass through it (in that order from superior to inferior) attached to the lateral wall, while CN VI is

“free-floating” and not attached to the wall of the cavernous sinus

The cavernous portion ot eh ICA is also here

Memonic – foramina through which CN V exits: divisions of the CN V exit owing to

tanding

oom

nly

uperior orbital fissure –

Foramen

otundum –

Foramen

vale –

Foramina in the middle cranial fossa – all structures pass through the sphenoid bone

Optic canal – CN II, ophthalmic artery, central retinal vein

Superior orbital fissure – CN III, IV, V

, VI, ophthalmic vein

Foramen rotundum – CN V

Foramen ovale – CN V

Foramen spinosum – middle meningeal a.

LAB 4: BISSECTION OF THE HEAD, PHARYNX & TEMPORAL REGION
Borders of the infratemporal fossa

Lateral – ramus of the mandible

Anterior – posterior aspect of the maxilla

Superior – inferior orbital fissure

Medial – pterygopalatine fossa and the lateral pterygoid of the sphenoid bone

Roof – greater wing of the sphenoid bone

Contents of the infratemporal fossa

Mandibular nerve (V

) – transmitted through the foramen ovale

Middle meningeal vessels

Sphenomandibular ligament, which attaches close to the spine of the sphenoid bone

Medial and lateral pterygoid muscles

Muscles of mastication – all innervated by CN V

Lateral pterygoid

Masseter

Medial pterygoid

Temporalis

Mnemonic – branches of the maxillary artery:

MID

town

ice

ite

eople’s

melly

nstep

iddle meningela

nferior alveolar

eep temporal

asseteric

uccal

osterior superior alveolar

phenopalatine (in the pterygopalatine fossa)

nfra orbital (in the pterygopalatine fossa)

Do not confuse buccal branch of CN V and VII

Buccal of V

is sensory and GSA

Buccal of VII is motor to the buccinator muscle and SVE

Schematic for tympanic nerve pathway
Tympanic nerve arises from CN IX and emerges with it from the jugular foramen

Tympanic nerve enters the middle ear via the tympanic canaliculus in the petrous part of the temporal bone

Tympanic nerve forms the tympanic plexus on promontory of the middle ear

The lesser petrosal nerve arises as a branch of the tympanic plexus

Lesser petrosal nerve penetrates the roof of a tympanic cavity (tegmen tympani) to enter middle cranial fossa

Lesser petrosal nerve exits the cranium through the foramen ovale

Preganglionic parasympathetic (GVE) fibers from the lesser petrosal nerve synapse in the otic ganglion

Postganglionic fibers pass to the parotid gland via branches of the auriculotemporal nerve (branch of V

)

LAB 5: ORBIT, PTERYGOPALATINE FOSSA & NASAL REGION

Clinical correlation – Central retinal artery

It’s occlusion leads to instant and total blindness of the affected eye

Superior, Middle, and Inferior Meatus

Sphenoidal sinus drains into superior meatus

Middle meatus contains the Hiatus semilunaris

Nasolacrimal duct drains into inferior meatus

LAB 6: MOUTH, TONGUE AND LARYNX
Mneumonic – muscles innervated by the Hypo

glossus

nerve, CN XII:

All muscles with the root “-

glossus

” (except palatoglossus – CN X) are innervated by CN XII

Mneumonic – muscles inervated by Vagus nerve, CN X

All muscles with the root “-

palat

” (except tensor veli palatini – CN V

) are inervated by CN X