Abdominopelvic splanchnic

Lower thoracic and

lumbar segments

sympathetic trunk

Pass medially and inferiorly to pre-

of vertebral ganglion of paraaortic plexus

Motor: presynaptic sympathetics for innervation of abdominopelvic blood vessels and viscera

Abducent (CN VI)

Pons

Become intradural on clivus; traverse

cavernous sinus and superior orbital

fissure to enter orbit

Motor: lateral rectus

Accessory (CN XI)

Cranial root: medulla

Spinal root: cervical

spinal cord

Spinal root ascends into cranial cavity

through foramen magnum, exits

through jugular foramen, traverses

posterior triangle of neck

Motor: sternocleidomastoid and trapezius

Ansa cervicalis

Superior root: hypoglossal

nerve (C1–C2 fibers)

Inferior root: cervical

plexus (C2–C3 fibers)

Descends on external surface of

carotid sheath and sternothyroid

Motor: omohyoid, sternohyoid,

Anterior ethmoidal

Nasociliary nerve (CN V1)

Arises in orbit, passes through anterior

ethmoidal foramen to cranial cavity, then

through cribriform plate of ethmoid to

nasal cavity

Sensory: dural of anterior cranial fossa; mucous membranes of sphenoidal sinus, ethmoidal cells, and upper nasal cavity

Anterior femoral cutaneous

Femoral nerve (L2–L3

fibers)

Arise in femoral triangle and pierce fascia

lata of thigh along path of sartorius muscle

Sensory: skin on medial and anterior aspects of thigh

Anterior interosseous

Median nerve in distal

part of cubital fossa

Passes inferiorly on interosseous

membrane

Motor: flexor digitorum profundus, flexor pollicis longus, and pronator quadratus

Auriculotemporal

Mandibular nerve (CN V3)

From posterior division of CN V3, it

passes between neck of mandible and

external acoustic meatus to accompany

superficial temporal artery

Sensory: skin anterior to auricle and posterior temporal region, tragus and part of helix of auricle, and roof of exterior acoustic meatus and upper tympanic membrane

Axillary

Terminal branch of

posterior cord of

brachial plexus

(C5–C6 fibers)

Passes to posterior aspect of arm

through quadrangular space in

company with posterior circumflex

humeral artery and then winds around

surgical neck of humerus; gives rise to

lateral brachialcutaneous nerve

Motor: teres minor and deltoid

Sensory: shoulder joint and skin over inferior part of deltoid

Buccal

Mandibular nerve (CN V3)

From the anterior division of CN V3 in

infratemporal fossa, it passes anteriorly

to reach cheek

Sensory: skin and mucosa of cheek, buccal gingiva adjacent to 2nd and 3rd molar teeth

Calcaneal branches

Tibial and sural nerves

of leg to skin on heel

Pass from distal part of posterior aspect

Sensory: skin of heel

Cardiac plexus

Cervical and cardiac

branches of vagus nerve

and cardiopulmonary

splanchnic nerves from

sympathetic trunk

From arch of aorta and posterior surface

of heart, fibers extend along coronary

arteries and to sinoatrial node

Sinoatrial nodal tissue and coronary arteries; parasympathetic fibers slow rate, reduce force of heartbeat, and constrict arteries; sympathetic fibers have opposite effect

Cardiopulmonary splanchnic

Cervical and upper thoracic

ganglia of sympathetic

trunk

Descend anteromedially to cardiac,

pulmonary, and esophageal plexuses

Motor: convey postsynaptic sympathetic fibers to nerve plexuses of thoracic viscera

Cavernous nerves of penis and clitoris

Parasympathetic fibers of

prostatic nerve plexus

Perforates perineal membrane to reach

erectile bodies of penis

Motor: helicine arteries of cavernous bodies; stimulation produces engorgement at arterial pressure (erection)

Cervical splanchnic

Cervical ganglia of sympa-

thetic trunk

Pass medially and inferiorly to cardiac

and pulmonary plexuses

Conducting tissue (sinoatrial and atrioventricular nodes) and coronary arteries

Chorda tympani

Facial nerve (CN VII) within

facial canal

Traverses tympanic cavity, passing

between incus and malleus; exits

temporal bone through petrotympanic

fissure to enter infratemporal fossa

where it merges with lingual nerve

Motor: submandibular and sublingual (salivary) glands

Sensory: taste sensation from anterior two thirds of tongue

Ciliary (long, short)

Long ciliary: nasociliary

nerve (CN V1)

Pass to posterior aspect of eyeball

Short ciliary: ciliary ganglion

Sensory: cornea, conjunctiva

Motor: ciliary body and iris

Cluneal (superior, middle,

and inferior)

Superior: posterior rami of L1, L2, and L3

Middle: posterior rami of

S1, S2, and S3

Inferior: posterior cutaneous nerve of thigh

Superior nerves cross iliac crest; middle nerves exit through posterior sacral foramina and enter gluteal region; inferior nerves curve around inferior border of gluteus maximus

Sensory: skin of buttock or gluteal region as far as greater trochanter

Coccygeal

Conus medullaris of

spinal cord

Anterior and posterior rami join adjacent rami of S4 and S5; anterior rami form coccygeal plexus, which gives rise to anococcygeal nerve

Sensory: skin over coccyx

Cochlear nerve

As a division of the

vestibulocochlear nerve e

(CN VIII)

Traverses internal acoustic meatus, ntering modiolus with spiral ganglia and peripheral processes in spiral lamina

Sensory: spiral organ (for hearing)

Common fibular (peroneal)

Terminal branch (with

tibialnerve) of sciatic

nerve (L4–S2 fibers)

Begins at apex of popliteal fossa; follows medial border of biceps femoris muscle to posterior aspect of head of fibula; bifurcates into superficial and deep fibular nerves as it winds around neck of fibula

Sensory: skin on lateral part of posterior aspect of leg through its branch, lateral sural cutaneous nerve; knee joint through its articular branch Motor: short head of biceps femoris

Common palmar digital

Median and superficial

branches of ulnar nerves

Run distally between long flexor tendons of palm, bifurcating in distal palm

Branches: proper palmar digital nerves, supplying skin and joints of palmar and distal dorsal aspect of fingers

Common plantar digital

Median and lateral plantar nerves

Run anteriorly in sole of foot between flexor tendons, bifurcating in distal sole

Branches: proper plantar digital nerves, supplying skin and joints of plantar and distal dorsal aspect of toes

Deep branch of radial nerve

Radial nerve just distal to

elbow

Winds around neck of radius in supinator; enters posterior compartment of forearm becoming posterior interosseous nerve

Motor: extensor carpi radialis brevis and supinator

Deep branch of ulnar nerve

Ulnar nerve at wrist as it passes between pisiform and hamate bones

(T1 fibers)

Passes deep between muscles of hypothenar eminence, then across palm with deep palmar (arterial) arch

Motor: hypothenar muscles (abductor, flexor, and opponens digiti minimi), lumbricals of 4th and 5th digits, all interossei, adductor pollicis, and deep head of flexor pollicis brevis

Deep fibular (peroneal)

Common fibular (peroneal) nerve

Arises between fibularis longus and neck of fibula; passes through extensor digitorum longus and descends on interosseous membrane; passes deep to extensor retinaculum, crosses distal end of tibia, and enters dorsum of foot

Motor: muscles of anterior compartment of leg and dorsum of foot

Sensory: skin of 1st interdigital cleft (i.e., skin on adjacent sides of 1st and 2nd toes); sends articular branches to joints it crosses

Deep petrosal

Internal carotid plexus

Traverses cartilage of foramen lacerum to join greater petrosal nerve at entrance to pterygoid canal

Conveys the postsynaptic sympathetic fibers destined for lacrimal gland and mucosa of nasal cavity, palate, and upper pharynx

Deep temporal

Mandibular nerve (CN V3)

Ascend temporal fossa deep to temporalis muscle

Motor: temporalis

Sensory: periosteum of temporal fossa

Dorsal branch of ulnar nerve

Ulnar nerve about 5 cm proximal to flexor retinaculum

Passes distally deep to flexor carpi ulnaris, then dorsally to perforate deep fascia and course along medial side of dorsum of hand, dividing into 2 to 3 dorsal digital nerves

Sensory: skin of medial aspect of dorsum of hand and proximal portions of 5th and medial half of 4th digit (occasionally also adjacent sides of proximal portions of 4th and 3rd fingers)

Dorsal scapular

Anterior ramus of C5 with frequent contribution from C4

Pierces scalenus medius, descends deep to levator scapulae, and enters deep surface of rhomboids

Motor: rhomboids; occasionally supplies levator scapulae

Esophageal plexus

Vagus nerve, sympathetic ganglia, greater splanchnic nerve

Distal to tracheal bifurcation, vagus and sympathetic nerves form a plexus around esophagus

Vagal (parasympathetic) and sympathetic fibers to smooth muscle and glands of inferior two thirds of esophagus

External nasal

Anterior ethmoidal nerve

(CN V1)

Runs in nasal cavity and emerges on face between nasal bone and lateral nasal

Sensory: skin on dorsum of nose, including tip of nose cartilage

Facial (CN VII)

Posterior border of pons

Runs through internal acoustic meatus

and facial canal of petrous part of

temporal bone, exiting through

stylomastoid foramen; main trunk forms

intraparotid plexus

Motor: stapedius, posterior belly of digastric, stylohyoid, facial, and scalp muscles

Sensory: some skin of external acoustic meatus

SEE ALSO intermediate nerve

Femoral

Lumbar plexus (L2–L4

fibers)

Passes deep to midpoint of inguinal

ligament, lateral to femoral vessels, and

divides into muscular and cutaneous

branches

Motor: anterior thigh muscles

Sensory: hip and knee joints; skin on anteromedial side of thigh and leg

Frontal

Ophthalmic nerve (CN V1)

Crosses orbit on superior aspect of levator

palpebrae superioris; divides into

supraorbital and supratrochlear branches

Sensory: skin of forehead, scalp, upper eyelid, and nose; conjunctiva of upper lid and mucosa of frontal sinus

Genitofemoral

Lumbar plexus (L1–L2

fibers)

Descends on anterior surface of psoas

major and divides into genital and femoral

branches

Sensory: femoral branch supplies skin over femoral triangle; genital branch supplies scrotum or labia majora Motor: genital branch to cremaster muscle

Glossopharyngeal (CN IX)

Glossopharyngeal (CN IX)

Exits cranium through jugular foramen,

passes between superior and middle

constrictors of pharynx to tonsillar fossa;

enters posterior third of tongue

Motor: somatic to stylopharyngeus; visceral (presynaptic parasympathetic) to parotid gland

Sensory: posterior two thirds of tongue (including taste), pharynx, tympanic cavity, auditory tube, carotid body, and sinus

Great auricular

Cervical plexus (C2–C3

fibers)

Ascends vertically over sterno,

cleidomastoidanterior and parallel to

external jugular vein

Sensory: skin of auricle, adjacent scalp, and over angle of jaw; parotid sheath

Greater occipital

As medial branch of posterior

ramus of spinal nerve C2

Pierces deep muscles of neck and

trapezius to ascend posterior scalp

to vertex

Motor: multifidus cervicis, semispinalis capitis

Sensory: posterior scalp

Greater palatine

Branch of pterygopalatine

ganglion (maxillary nerve)

Passes inferiorly through greater palatine

canal and foramen

Motor: postsynaptic parasympathetics to palatine glands

Sensory: mucosa of hard palate

Greater petrosal

Genu of facial nerve (CN VII)

Exits facial canal through hiatus for

greater petrosal nerve; courses across to

tegmen tympani and passes through

cartilage of foramen lacerum to join

deep petrosal nerve at opening of

pterygoid canal

Motor: presynaptic parasympathetics pterygopalatine ganglion for innervation of lacrimal and nasal, palatine, and upper pharyngeal mucous glands

Greater splanchnic

5th–6th through 9th–10th

thoracic sympathetic ganglia

Highest abdominopelvic splanchnic

nerve; passes anteromedially on bodies

of thoracic vertebrae, piercing diaphragm

to converge on root of celiac trunk

they supply

Motor: conveys presynaptic sympathetics to celiac ganglia for innervation of celiac arteries and derivatives, and of that portion of gut

Hypogastric

As continuation of superior hypogastric plexus into pelvis

Courses anteriorly to sacrum within

hypogastric sheath to merge with pelvic

splanchnic nerves in inferior hypogastric

plexus

Motor: conveys presynaptic and postsynaptic sympathetic fibers destined for pelvic viscera Sensory: conveys pain fibers from intraperitoneal pelvic viscera (e.g., fundus, body of uterus)

Hypoglossal (CN XII)

Between pyramid and olive

of myencephalon

Passes through hypoglossal canal, then

runs inferiorly and anteriorly, passing

medially to angle of mandible and

between mylohyoid and hyoglossus

to reach muscles of tongue

Motor: intrinsic and extrinsic muscles of tongue (exception: palatoglossus)

Iliohypogastric

Lumbar plexus (L1 fibers)

Parallels iliac crest; pierces transverse

abdominal muscle; branches pierce

external oblique aponeurosis to reach

inguinal and pubic regions

Motor: internal oblique and transverse abdominal muscles

Sensory: lateral cutaneous branch supplies superolateral quadrant of buttocks, skin over iliac crest, and hypogastric region

Ilioinguinal

Lumbar plexus (L1 fibers)

Passes between 2nd and 3rd layers of abdominal muscles, passes through inguinal canal, and divides into femoral and scrotal or labial branches

Motor: lowermost part of internal oblique and transverse abdominal muscles

Sensory: femoral branch supplies skin over femoral triangle; genital branch supplies mons pubis and adjacent skin of labia majora or scrotum

Inferior alveolar

As terminal branch (with

lingual nerve) of posterior

trunk of mandibular nerve

(CN V3)

Descends between lateral and medial pterygoid muscles of infratemporal fossa to enter mandibular canal of mandible

Sensory: lower teeth, periodontium, periosteum, and gingiva of lower jaw. SEE ALSO nerve to mylohyoid, mental nerve

Inferior anal (rectal)

Pudendal nerve (S2–S4

fibers)

Arises at entry to pudendal canal (ischial spine), courses medially through ischioanal fat pad to anal canal

Motor: external anal sphincter

Sensory: anoderm, perianal skin

Inferior gluteal

Sacral plexus (L5–S2 fibers)

Leaves pelvis through greater sciatic foramen inferior to piriformis and divides into several branches

Motor: gluteus maximus

Infraorbital

Terminal branch of maxillary

nerve (CN V2)

Runs in floor of orbit and emerges at infraorbital foramen

Sensory: skin of cheek, lower lid, lateral side of nose and inferior septum and upper lip, upper premolar incisors and canine teeth, mucosa of maxillary sinus and upper lip

Infratrochlear

Nasociliary nerve (CN V1)

Follows medial wall of orbit to upper eyelid

Sensory: skin and conjunctiva (lining) of upper eyelid

Intercostals

Anterior rami of T1–T11

nerves

Run in intercostal spaces between internal and innermost layers of intercostal muscles

Motor: intercostal muscles; lower nerves supply muscles of anterolateral abdominal wall

Sensory: skin overlying and pleura and peritoneum deep to muscles innervated

Intermediary

From the pons as a smaller

root of the facial nerve

(CN VII)

Traverses internal acoustic meatus, merging at its distal end with larger (root of) facial nerve

Motor: presynaptic parasympathetics destined for pterygopalatine and submandibular ganglia through greater petrosal nerve and chorda tympani respectively

Sensory: taste from anterior two thirds of tongue and soft palate

Lacrimal

Ophthalmic nerve (CN V1)

Passes through palpebral fascia of upper eyelid near lateral angle (canthus) of eye

Sensory: a small area of skin and conjunctiva of lateral part of upper eyelid

Lateral branch of median nerve

Median nerve as it enters

Runs laterally to palmar thumb and palm of hand radial side of index finger

Motor: 1st lumbrical

Sensory: skin of palmar and distal dorsal aspects of thumb and radial half of index finger

Lateral cutaneous nerve of

forearm

Continuation of musculo-

cutaneous nerve (C6–C7

fibers)

Descends along lateral border of forearm to wrist

Sensory: skin of lateral aspect of forearm

Lateral cutaneous nerve of thigh

Lumbar plexus (L2–L3

fibers)

Passes deep to inguinal ligament, 2–3 cm medial to anterior superior iliac spine

Sensory: skin on anterior and lateral aspects of thigh

Lateral pectoral

Lateral cord of brachial

plexus (C5–C7 fibers)

Pierces clavipectoral fascia to reach deep surface of pectoral muscles

Motor: primarily pectoralis major but sends a loop to medial pectoral nerve that innervates pectoralis minor

Lateral plantar

Smaller terminal branch of

the tibial nerve

(S1–S2 fibers)

Passes laterally in foot between quadratus plantae and flexor digitorum brevis muscles and divides into superficial and deep branches

Motor: quadratus plantae, abductor digiti minimi, flexor digiti minimi brevis; deep branch supplies plantar and dorsal interossei, lateral three lumbricals, and adductor hallucis Sensory: skin on sole lateral to a line splitting 4th digit

Least splanchnic

12th (lowest) thoracic

ganglion of sympathetic

trunk

Passes through diaphragm with sympathetic trunk and ends in renal plexus

Motor: presynaptic sympathetic to renal arteries and derivatives

Lesser occipital

Cervical plexus (C2–C3

fibers)

Ascends posterosuperiorly, parallel to anterosuperior border of sternocleidomastoid

Sensory: skin of posterior surface of auricle and adjacent scalp

Lesser palatine

Pterygopalatine ganglion

(maxillary nerve—CN V2)

Passes inferiorly through palatine canal and lesser palatine foramen

Motor: postsynaptic parasympathetics to glands of soft palate Sensory: mucosa of soft palate

Lesser petrosal

Tympanic plexus (glosso-

pharyngeal nerve—CN IX)

Perforates tegmen tympani to exit tympanic cavity into middle cranial fossa; runs anteriorly to descend through sphenopetrosal fissure

Motor: conveys presynaptic parasympathetic fibers to otic ganglion for secretomotor innervation of parotid or foramen ovale gland

Lesser splanchnic

10th and 11th thoracic

ganglia of sympathetic trunk

Descends anteromedially to perforate diaphragm to reach aorticorenal ganglion

Motor: presynaptic sympathetics to prevertebral ganglia

Sensory: visceral afferents from upper gastrointestinal tract

Lingual

Terminal branch (with inferior

alveolar nerve) of posterior

trunk of mandibular nerve

(CN V3)

Joined by chorda tympani in infratemporal fossa; passes anteroinferiorly between lateral and medial pterygoid muscles, and above mylohyoid to enter oral cavity

Motor: presynpatic parasympathetic fibers to submandibular ganglion for submandibular and sublingual salivary glands

Sensory: anterior two thirds of tongue, floor of mouth, and lingual mandibular gingiva

Long thoracic

Anterior rami of C5–C7

Descends posterior to C8 and T1 rami and passes distally on external surface of serratus anterior

Motor: serratus anterior

Lower subscapular

Posterior cord of brachial

plexus (C5–C6 fibers)

Passes inferolaterally, deep to subscapular artery and vein to subscapularis and and teres major

Motor: inferior portion of subscapularis teres major

Lumbar splanchnic

Lumbar ganglia of sympa-

thetic trunks

Pass anteromedially on bodies of lumbar vertebrae to prevertebral ganglia of paraaortic plexus

Motor: presynaptic sympathetics for lower abdominal and pelvic viscera Sensory: visceral afferents from same

Mandibular (CN V3)

Trigeminal ganglion (motor

root from pons)

Descends through foramen ovale into infratemporal fossa; divides into anterior and posterior trunks, anterior ramifying immediately into several smaller branches, posterior bifurcating into lingual and inferior alveolar nerves

Motor: muscles of mastication, mylohyoid, anterior belly of digastric, tensor tympani, and tensor veli palatini Sensory: skin overlying mandible (except angle), lower half of mouth (including teeth, gingiva, mucosa of floor and vestibule, and anterior two thirds of tongue), and temporo-mandibular joint

Masseteric

Anterior trunk of mandibular

nerve (CN V3)

Passes laterally through mandibular notch

Motor: masseter

Sensory: temporomandibular joint

Maxillary (CN V2)

Trigeminal ganglion

Runs anteriorly through foramen rotundum into pterygopalatine fossa, sending sensory roots to the pterygopalatine ganglion (branches of the ganglion are considered branches of the maxillary nerve); main trunk continues anteriorly through infraorbital fissure as infraorbital nerve

Motor: no motor fibers initially; branches of pterygopalatine ganglion distribute postsynaptic parasympathetic fibers to lacrimal gland and mucosalxglands of nasal cavity, palate, and upper pharynx Sensory: skin overlying maxilla, mucosa of posteroinferior nasal cavity and maxillary sinus; upper half of mouth (including teeth, gingiva, and mucosa of palate, vestibule, and cheek)

Medial branch of median

nerve

Median nerve as it enters

palm of hand

Runs medially to adjacent sides of index, middle, and ring fingers

Motor: 2nd lumbrical

Sensory: skin of palmar and distal dorsal aspects of adjacent sides of the 2nd, 3rd, and 4th digits

Medial cutaneous nerve of arm

Medial cord of brachial

plexus (C8 and T1 fibers)

Runs along the medial side of axillary vein and communicates with intercostobrachial nerve

Sensory: skin on medial side of arm

Medial cutaneous nerve of forearm

Medial cord of brachial

plexus (C8 and T1 fibers)

Runs between axillary artery and vein

Sensory: skin over medial side of forearm

Medial cutaneous nerve of leg

Saphenous nerve

Descends medial side of leg with greater saphenous vein

Skin of anteromedial side of leg and medial side of foot

Medial dorsal cutaneous

nerve

Superficial fibular (peroneal)

Descends across ankle anteriorly running nerve onto medial aspect of dorsum of foot

Supplies most of skin of dorsum of foot; proximal portion of toes, except for web between great and 2nd toes

Medial pectoral

Medial cord of brachial

plexus (C8 and T1 fibers)

Passes between axillary artery and vein and enters deep surface of pectoralis minor

Motor: pectoralis minor and part of pectoralis major

Medial plantar

Larger terminal branch of

the tibial nerve (L4 and

L5 fibers)

Passes distally in foot between abductor hallucis and flexor digitorum brevis and divides into muscular and cutaneous branches

Motor: abductor hallucis, flexor digitorum brevis, flexor hallucis brevis, and 1st lumbrical

Sensory: skin of medial side of sole of foot and sides of 1st 3 digits

Median

Arises by two roots, one

from the lateral cord of

brachial plexus (C6–C7

fibers) and one from medial

cord (C8 and T1 fibers);

roots join lateral to axillary

artery

Over length of arm, crosses to medial side of brachial artery; exits cubital fossa between heads of pronator teres, running between intermediate and deep layers of anterior forearm compartment; becomes superficial proximal to wrist and passes deep to flexor retinaculum (transverse carpal ligament) as it passes through carpal tunnel to the hand

Motor: flexor muscles in forearm (except flexor carpi ulnaris, ulnar half of flexor digitorum profundus); thenar muscles (except adductor pollicis and deep head of flexor pollicis brevis), lateral lumbricals (for 2nd and 3rd) digits Sensory: skin of the palmar and distal dorsal aspects of the lateral (radial) 3-1/2 digits and adjacent palm

Mental

Terminal branch of inferior

alveolar nerve (CN V3)

Emerges from mandibular canal at mental foramen

Sensory: skin of chin; skin and mucosa of lower lip

Musculocutaneous

Lateral cord of brachial

plexus (C5–C7 fibers)

Enters deep surface of coracobrachialis and descends between biceps brachii and brachialis

Motor: flexor muscles of arm (coracobrachialis, biceps brachii, and brachialis)

Sensory: continues as lateral antebrachial cutaneous nerve

Nasociliary

Ophthalmic nerve (CN V1)

Arises in superior orbital fissure, passes anteromedially across retrobulbar orbit, providing sensory root to ciliary ganglion and terminating as infratrochlear nerve and nasal branches

Motor: no motor fibers initially; branches of ciliary ganglion (short ciliary nerves) convey postsynapatic sympathetics and parasympathetics to ciliary body and iris

Sensory: tactile sensation from eyeball (conjunctiva and cornea); mucous membrane of ethmoidal cells and anterosuperior nasal cavity; skin of root, dorsum, and apex of nose

Nasopalatine

Pterygopalatine ganglion

(maxillary nerve—CN V2)

Exits pterygopalatine fossa through sphenopalatine foramen; crossing to and then running anteroinferiorly across nasal septum; passes through incisive foramen to palate

Motor: postsynaptic parasympathetics to mucosal glands of nasal septum Sensory: mucosa of nasal septum, anteriormost hard palate

Nerves to lateral/medial

pterygoid

Anterior trunk of mandibular

nerve (CN V3)

Arise in infratemporal fossa immediately inferior to foramen ovale

Motor: lateral and medial pterygoid muscles

Nerve to mylohyoid

Inferior alveolar nerve

Arises from posterior aspect of inferior alveolar nerve immediately outside man-dibular foramen; descends in bony groove on medial aspect of ramus of mandible

Motor: mylohyoid and anterior belly of digastric muscle

Nerve to obturator internus

Sacral plexus (L5, S1, and

S2)

Enters gluteal region through greater sciatic foramen inferior to piriformis; descends posteriorly to ischial spine; enters lesser sciatic foramen and passes to obturator internus

Motor: superior gemellus and obturator internus

Nerve of pterygoid canal

Formed by merger of greater

and deep petrosal nerves

Traverses pterygoid canal to reach pterygopalatine ganglion in pterygopalatine fossa

Motor: conveys postsynaptic sympathetic and presynaptic parasympathetic fibers to pterygopalatine ganglion

Nerve to quadratus femoris

Sacral plexus (L5, S1, and

S2)

Leaves pelvis through greater sciatic foramen deep to sciatic nerve

Motor: inferior gemellus and quadratus femoris

Sensory: hip joint

Nerve to stapedius muscle

Facial nerve (CN VII)

Arises as facial nerve descends posterior to muscle in facial canal

Motor: stapedius

Nerve to tensor tympani

muscle

Otic ganglion (mandibular

nerve—CN V3)

Courses along cartilaginous portion of pharyngotympanic (auditory) tube to hemicanal for tensor tympani

Motor: tensor tympani

Nerve to tensor veli palatini muscle

Anterior trunk of mandibular

nerve—(CN V3)

Arises as a branch of nerve to medial pterygoid

Motor: tensor veli palatini

Obturator

Lumbar plexus

(L2–L4 fibers)

Enters thigh through obturator foramen and divides; its anterior branch descends between adductor longus and adductor brevis; its posterior branch descends between adductor brevis and adductor magnus

Motor: anterior branch supplies adductor longus, adductor brevis, gracilis, and pectineus; posterior branch supplies obturator externus and adductor magnus

Sensory: skin of medial thigh above knee

Oculomotor (CN III)

Interpeduncular fossa of

mesencephalon

Pierces dura lateral to posterior clinoid process, runs in lateral wall of cavernous sinus, enters orbit through superior fissure and divides into superior and inferior branches

Motor: somatic: all extraocular muscles except superior oblique and lateral rectus; presynaptic paraorbital sympathetic fibers to ciliary ganglion for ciliary body and sphincter pupillae

Olfactory (CN I)

Olfactory cells in olfactory

epithelium (mucosa) of roof

of nasal cavity plate

Approximately 20 bundles of nerve fibers ascend through foramina of cribriform of ethmoid to reach olfactory bulbs (anterior cranial fossa)

Sensory: olfactory mucosa (sense of smell)

Ophthalmic (CN V1)

Trigeminal ganglion

Passes anteriorly in lateral wall of cavernous sinus to enter orbit through superior orbital fissure, branching into frontal, nasociliary, and lacrimal nerves

Sensory: general sensation from eyeball (conjunctiva and cornea); mucous membrane of ethmoidal cells and frontal sinus, dura of anterior cranial fossa, falx cerebri and tentorium cerebelli, anterosuperior nasal cavity; skin of forehead, upper lid; root, dorsum, and apex of nose

Optic (CN II)

Ganglion cells of retina

Exits orbit through optic canals; fibers from nasal half of retina cross to contralateral side at chiasm; fibers pass through optic tracts to geniculate bodies, superior colliculus, and pretectum

Sensory: vision from retina

Palmar cutaneous branch of

median nerve

Arises from median nerve

just proximal to flexor

retinaculum

Passes between tendons of palmaris longus and flexor carpi radialis and runs superficially to flexor retinaculum

Sensory: skin of central palm

Palmar cutaneous branch of

ulnar nerve

Arises from ulnar nerve near

middle of forearm

Descends on ulnar artery and perforates deep fascia in the distal third of forearm

Sensory: skin at base of medial palm, overlying medial carpals

Pelvic splanchnic

Sacral plexus (S2–S4 fibers)

Run anteriorly and inferiorly to merge with inferior hypogastric plexus

Motor: presynaptic parasympathetic fibers for pelvic viscera, descending and sigmoid colon

Sensory: visceral afferent fibers from subperitoneal pelvic viscera (cervix of uterus and upper vagina, floor of bladder, rectum and upper anal canal; prostate)

Perineal

Terminal branch (with dor-

sal nerve of penis or clitoris)

of pudendal nerve (S2–S4

fibers)

Separates from pudendal nerve on exit from pudendal canal; runs to superficial perineum dividing into a superficial cutaneous branch (posterior labial/scrotal) and a deep motor branch triangle

Motor: muscles of urogenital triangle (superficial and deep perineal muscles)

Sensory: skin of posterior urogenital (posterior portion of labia

majora and minora, vestibule of vagina; posterior aspect of scrotum)

Pharyngeal

Pterygopalatine ganglion

Passes posteriorly through palatovaginal canal

Supplies mucosa of nasopharynx posterior to pharyngotympanic (auditory) tubes

Phrenic

Cervical plexus (C3–C5

fibers)

Passes through superior thoracic aperture and runs between mediastinal pleura and pericardium

Motor: diaphragm

Sensory: pericardial sac, mediastinal and diaphragmatic pleura, and diaphragmatic peritoneum

Posterior auricular

As first extracranial branch

of facial nerve (CN VII)

Passes posterior to ear, sending branch to occipital region

Motor: posterior auricular muscle and intrinsic auricular muscles, occipital belly of occipitofrontalis (epicranius)

Posterior cutaneous nerve of arm

Radial nerve (C5–C8 fibers)

Emerges from under posterior border of deltoid, between long and lateral heads of triceps brachii

Sensory: skin of posterior aspect of arm

Posterior cutaneous nerve

of forearm

Arises in arm from radial

nerve (C5–C8 fibers)

Perforates lateral head of triceps and descends along lateral side of arm and posterior aspect of forearm to wrist

Sensory: skin of distal posterior arm, posterior aspect of forearm

Posterior cutaneous nerve of thigh

Sacral plexus (S1–S3 fibers)

Leaves pelvis through greater sciatic foramen inferior to piriformis, runs deep to gluteus maximus, and emerges from its inferior border

Sensory: skin of buttock through inferior cluneal branches and skin over posterior aspect of thigh and calf; lateral perineum, upper medial thigh through perineal branch

Posterior ethmoidal

Nasociliary

Leaves orbit through posterior ethmoidal foramen

Supplies ethmoidal and sphenoidal paranasal sinuses

Posterior inferior nasal

Greater palatine

Arise in greater palatine canal, pierce through perpendicular plate of palatine bone

Mucosa of inferior nasal concha and walls of inferior and middle nasal meatuses

Posterior interosseous

Terminal branch of deep

branch of radial nerve

(continuation of deep radial

after emerging from

supinator)

Runs between superficial and deep layers of posterior forearm, then passes between extensor pollicis longus and interosseous membrane

Motor: extensor carpi ulnaris, extensors of digits (including thumb), and abductor pollicis longus

Posterior labial

Perineal nerve

Emerge from pudendal canal and ramify in subcutaneous tissue

Skin of posterior portion of labium majus

Pudendal

Sacral plexus (S2–S4)

Enters gluteal region through greater sciatic foramen inferior to piriformis; descends posteriorly to sacrospinous ligament; enters perineum through lesser sciatic foramen

Supplies most motor and sensory innervation to perineum (supplies no structures in gluteal region)

Pulmonary plexus

Vagus nerve and cardio-

pulmonary splanchnic nerves

from sympathetic trunk

Forms on primary bronchi and extends along root of lung and bronchial subdivisions

Motor: parasympathetic fibers constrict bronchioles; sympathetic fibers dilate them

Radial

Terminal branch of posterior

cord of brachial plexus

(C5–C8 and T1 fibers)

Descends posterior to axillary artery; enters radial groove with deep brachial artery to pass between long and medial heads of triceps; bifurcates in cubital fossa into superficial and deep radial nerves

Motor: proximal to bifurcation, innervates triceps brachii, anconeus, brachioradialis, and extensor carpi radialis longus muscles

Sensory: skin on posterior aspect of arm and forearm via posterior cutaneous nerves of arm and forearm

Recurrent (thenar) branch

of median nerve

Median nerve immediately

distal to flexor retinaculum

Loops around distal border of flexor retinaculum and enters thenar muscles

Motor: abductor pollicis brevis, opponens pollicis, and superficial head of flexor pollicis brevis

Recurrent laryngeal

Vagus nerve (CN X)

Loops around subclavian on right; on left runs around arch of aorta and ascends in tracheoesophageal groove

Motor: intrinsic muscles of larynx (except cricothyroid)

Sensory: inferior to level of vocal folds

Saphenous

Femoral nerve

Descends with femoral vessels through femoral triangle and adductor canal, then descends with great saphenous vein

Sensory: skin on medial side of leg and foot

Sciatic

Sacral plexus (L4–S3 fibers)

Enters gluteal region through greater sciatic foramen inferiorly to piriformis, descends along posterior aspect of thigh, and divides proximally to knee into tibial and common fibular peroneal nerves

Motor: hamstrings by tibial division (except for short head of biceps femoris, which is innervated by its common fibular division)

Sensory: provides articular branches to hip and knee joints Motor: subclavius

Subclavian nerve

Superior trunk of brachial

plexus (C5–C6; often C4

as well)

Descends posterior to clavicle and anterior to brachial plexus and sub clavian artery

Sensory: sternoclavicular joint

Subcostal

Subcostal

Courses along inferior border of 12th rib in same manner as intercostal nerves

Motor: muscles of anterolateral abdominal wall

Sensory: lateral cutaneous branch supplies skin inferior to anterior iliac crest

Suboccipital

Posterior ramus of C1

spinal nerve

Emerges between occipital bone and atlas, inferior to transverse part of vertebral artery, into suboccipital triangle; communicates with occipital nerve (C2)

Motor: suboccipital muscles (rectus capitis major and minor, obliquus capitis inferior and superior)

Superficial branch of

radial nerve

Continuation of radial nerve

after deep branch is given off

in cubital fossa

Passes distally, anterior to pronator teres and deep to brachioradialis; emerging to pierce deep fascia at wrist and pass onto dorsum of hand

Sensory: skin of lateral (radial) half of dorsum of hand and thumb, proximal portions of dorsal aspects of 2nd and 3rd digits, and of lateral (radial) half of 4th digit

Superficial branch of

ulnar nerve

Arise from ulnar nerve at

wrist as they pass between

pisiform and hamate bones

Passes palmaris brevis and divides into 2 common palmar digital nerves

Motor: palmaris brevis

Sensory: skin of palmar and distal dorsal aspects of 5th digit and of medial (ulnar) side of 4th digit and proximal portion of palm

Superficial fibular (peroneal)

Common fibular (peroneal)

nerve

Arises between fibularis longus and neck of fibula and descends in lateral compartment of leg; pierces deep fascia at distal third of leg to become cutaneous and send branches to foot and digits

Motor: fibularis (peroneus) longus and brevis

Sensory: skin on distal third of anterior surface of leg and dorsum of foot and all digits, except lateral side of 5th and adjoining sides of 1st and 2nd digits

Superior alveolar

Maxillary nerve (CN V2) or

its continuation as infra-

orbital nerve

Posterior: emerges from pterygomaxillary fissure into infratemporal fossa; pierces posterior aspect of maxilla

Middle and anterior: arises from infraorbital nerve in roof of maxillary sinus, descends walls of sinus

Sensory: mucosa of maxillary sinus, maxillary teeth, and gingiva

Superior gluteal

Sacral plexus (L4–S1 fibers)

Leaves pelvis through greater sciatic foramen superior to piriformis and runs between gluteus medius and minimus

Motor: gluteus medius, gluteus minimus, and tensor fasciae latae

Superior laryngeal

Vagus (CN X)

Descends in parapharyngeal space; lateral to thyroid cartilage divides into internal and external laryngeal nerves; former pierces thyrohyoid membrane; latter runs inferomedially to gap between cricoid and thyroid cartilages

Motor: cricothyroid muscle (external laryngeal nerve)

Sensory: supraglottic

Supraclavicular (lateral,

intermediate, medial)

Cervical plexus (C3 and C4

fibers)

Arise from a common trunk that emerges at center of posterior border of sterno-cleidomastoid; fan out as they descend onto lower neck, upper thorax, and shoulder

Sensory: skin of lower anterolateral neck, uppermost thorax, and shoulder

Supraorbital

Continuation of frontal nerve (CN V1)

Emerges through supraorbital notch, or foramen, and breaks up into small branches

Sensory: mucous membrane of frontal sinus and conjunctiva (lining) of upper eyelid; skin of forehead as far as vertex

Suprascapular

Superior trunk of brachial

plexus (C5–C6; often C4 also)

Passes laterally across posterior triangle of neck, through scapular notch under superior transverse scapular ligament

Motor: supraspinatus, infraspinatus muscles

Sensory: superior and posterior glenohumeral (shoulder) joint

Supratrochlear

Frontal nerve (CN V1)

Passes superiorly on medial of supraorbital nerve and divides into 2 or more branches

Sensory: skin in middle of forehead to hairline

Sural

Usually arises from merging of medial and lateral sural cutaneous nerves from tibial and common fibular (peroneal) nerves, respectively l

Descends between heads of gastrocnemius and becomes superficial at middle of leg; descends with small saphenous vein and passes posterior to lateral malleolus to ateral side of foot

Sensory: skin on posterior and lateral aspects of leg and lateral side of foot

Tentorial

Intracranial portion of

ophthalmic nerve (CN V1)

Arises as recurrent branch passing abruptly posteriorly around margins of tentorial notch onto superior aspect of tentorium cerebelli and ascending posterior limb of falx cerebri

Sensory: supratentorial dura mater (superior aspect of tentorium cerebri and falx cerebri)

Thoracic splanchnic

Thoracic ganglia of

sympathetic trunk

Pass anteromedially on bodies of

thoracic vertebrae as lower cardiopulmonary splanchnic nerves to thoracic autonomic plexuses (cardiac, pulmonary, and esophageal) and as upper abdominopelvic splanchnic nerves to prevertebral ganglia of paraaortic plexus

Motor: splanchnic nerves from 1st through 5th thoracic ganglia convey postsynaptic sympathetic fibers to heart, lungs, and esophagus; those from 6th through 12th thoracic ganglia (i.e., greater, lesser, and least splanchnic nerves) convey presynaptic sympathetic fibers to prevertebral ganglia

Thoracoabdominal

Continuation of lower inter-

costal nerves (T7–T11)

Cross costal margin to run between 2nd and 3rd layers of abdominal muscles

Motor: anterolateral abdominal muscles

Sensory: overlying skin, underlying peritoneum, and periphery of diaphragm

Thoracodorsal

Posterior cord of brachial

plexus (C6–C8 fibers)

Arises between upper and lower subscapular nerves and runs inferolaterally along posterior axillary wall to latissimus dorsi

Motor: latissimus dorsi

Tibial

Sciatic nerve (L4–S3 fibers)

Forms as sciatic bifurcates at apex of popliteal fossa; descends through popliteal fossa and lies on popliteus; runs inferiorly on tibialis posterior with posterior tibial vessels; terminates beneath flexor retinaculum by dividing into medial and lateral plantar nerves

Motor: muscles of posterior compartment of thigh (except short head of biceps), popliteal fossa, posterior compartment of leg, and sole of foot

Sensory: knee joint; skin of leg (through medial sural), and sole of foot (through medial and lateral plantar nerves)

Transverse cervical

Cervical plexus (C2 and C3

fibers)

Emerges from middle of posterior border of sternocleidomastoid muscle; runs anteriorly across muscle

Sensory: skin overlying anterior triangle of neck

Trigeminal (CN V)

Lateral surface of pons by 2

roots: motor and sensory

Roots cross medial part of crest of petrous part of temporal bone, entering trigeminal cave of dura mater lateral to body of sphenoid and cavernous sinus; sensory root leads to trigeminal ganglion; motor root bypasses ganglion, becoming part of mandibular nerve (CN V3)

Motor: somatic: muscles of mastication, mylohyoid, anterior belly of digastric, tensor tympani, and tensor veli palatini; visceral: distributes postsynaptic parasympathetic fibers of head to their destinations

Sensory: dura of anterior and middle cranial fossae, facial skin, teeth, gingiva, mucosa, nasal cavity, paranasal sinuses, and mouth

Trochlear (CN IV)

Dorsolateral aspect of

mesencephalon below infe-

rior colliculus (only cranial nerve to emerge from dorsal aspect of brainstem)

Runs longest intracranial course, passing around brainstem to enter dura in free edge of tentorium close to posterior clinoid process; runs in lateral wall of cavernous sinus, entering orbit via superior orbital fissure

Motor: superior oblique muscle

Tympanic

As 1st extracranial branch of glossopharyngeal nerve (CN IX), from inferior (petrosal) glossopharyngeal ganglion

Passes in recurrent manner into tympanic canaliculus, entering tympanic cavity and ramifying on promontory of labyrinthine wall as tympanic plexus

Motor: conveys presynaptic parasympathetic fibers that will reach otic ganglion for secretomotor innervation of parotid gland Sensory: mucosa of tympanic cavity, mastoid cells, and pharyngotympanic (auditory) tube

Ulnar

Terminal branch of medial

cord of brachial plexus (C8

and T1 fibers; often also

receives C7 fibers)

Terminal branch of medial cord of brachial plexus (C8 and T1 fibers; often also receives C7 fibers)

Motor: most intrinsic muscles of hand (hypothenar, interosseous, adductor pollicis, and deep head of flexor pollicis brevis, plus medial lumbricals [for 4th and 5th digits])

Sensory: skin of palmar and distal dorsal aspects of medial (ulnar) 1-1/2 digits and adjacent palm

Upper subscapular

Branch of posterior cord of

brachial plexus (C5 and C6

fibers)

Passes posteriorly and enters subscapularis

Motor: superior portion of subscapularis

Vagus (CN X)

Through 8–10 rootlets from

medulla of brainstem

Enters superior mediastinum posteriorly to sternoclavicular joint and brachio-cephalic vein; gives rise to recurrent laryngeal nerve; continues into abdomen

Motor: voluntary muscle of larynx and upper esophagus; involuntary muscle and glands of tracheobronchial tree, gut (to left colic flexure), and heart through pulmonary plexus, esophageal plexus, and cardiac plexus Sensory: pharynx, larynx, reflex afferents from same areas as above

Vestibular

As a division of vestibulocochlear nerve (CN VIII)

Traverses internal acoustic meatus to reach vestibular ganglion at fundus; branches pass to vestibule of bony labyrinth

Sensory: cristae of ampullae of semicircular ducts, maculae of saccule and utricle (for sense of equilibration)

Vestibulocochlear (CN VIII)

Groove between pons and

myencephalon

Traverses internal acoustic meatus,

dividing into cochlear and vestibular

nerves

Sensory: spiral organ (for sense of hearing) and cristae of ampullae of semicircular ducts, maculae of saccule and utricle (for sense of equilibration)

Zygomatic

Maxillary nerve (CN V2)

Arises in floor of orbit, divides into

zygomaticofacial and zygomaticotemporal

nerves, which traverse foramina of same

name; communicating branch joins

lacrimal nerve

Sensory: skin over zygomatic arch and anterior temporal region

Motor: conveys secretory postsynaptic parasympathetic fibers from ptery-gopalatine ganglion to lacrimal gland