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385 Cards in this Set

  • Front
  • Back
number and types of vertebrae
33 total vertebrae (7 cervical; 12 thoracic; 5 lumbar; 5 sacral [fused]; 4 coccygeal fused]
major components of an individual vertebra
body; vertebral arch (pedicles & lamina); 1 spinous process; 2 costal/transverse processes, superior/inferior articular processes
spina bifida (definition & types)
failure of lamina (vertebral arch) to fuse; types: occulta (asymptomatic); cystica (cyst protrudes through gap, can result in meningocele or meningomyelocele); myeloschisis (neural tube fails to close)
four curvatures of the spine (names and directions)
cervical (anterior); thoracic (posterior); lumbar (anterior); sacral (posterior)
abnormal curvatures of the spine
kyphosis (increased posterior curvature of thoracic vertebrae); lordosis (increased anterior curvature of lumbar vertebrae); scoliosis (abnormal lateral curvature)
name of joints between adjacent vertebrae
zygoapophyseal (or facet) joints between superior and inferior articular processes;
components and function of an intervertebral disk
outside = annulus fibrosus ; inside = nucleus pulposus ; function = absorb shock and distribute weight evenly
ligaments linking adjacent vertebrae
anterior longitudinal ligament, posterior longitudinal ligament, ligamentum flavum (between lamina), interspinous ligament, supraspinous ligament, intertransverse ligament
structure and function of intervertebral foramina
top/bottom = pedicles of adjacent vertebrae, anterior wall = vertebral body, posterior wall = facet joint; purpose = to transmit dorsal and ventral roots of spinal nerves
contents of the vertebral canal (exterior to interior)
epidural space (fat & internal vertebral venous plexus); dura mater; subdural space (potential space); arachnoid mater; subarachnoid space (CSF); pia mater; spinal cord/nerves
components of the meninges (external to internal)
dura mater, subdural space, arachnoid mater, subarachnoid space (CSF), pia mater
vertebral level at which the meninges terminate
meninges (dura, arachnoid, pia) terminate at the level of the S2 vertebral (in the cauda equina)
CSF (location; composition; function)
CSF: location = ventricles of brain/subarachnoid space; composition = clear fluid (few cells, low glucose, low protein); function = cushioning brain/absorbing waste/transporting hormones
conus medullaris
the most inferior end of the spinal cord; located at the level of the L2 vertebra
which spinal nerves exit superior to the vertebrae with the SAME name? inferior?
because of the 'extra' C8 spinal nerve: C1-C7 spinal nerves = superior to C1-C7 vertebrae; T1 & down = inferior to T1 & down
cauda equina
the dorsal/ventral roots of lumbar and sacral spinal nerves that extend inferior to the conus medullaris (end of the spinal cord in the vertebral column)
location of lumbar puncture (and layers passed through)
location: between L4 & L5 vertebrae (i.e. below the inferior end of the spinal cord); layers transversed: skin; superficial/deep fascia; ligamentum flavum (or supraspinous & interspinous ligaments); intralaminar space; epidural space; dura mater; arachnoid mater
radiculopathy (definition and causes)
radiculopathy = compression of roots of spinal nerves in the intervertebral foramina that causes pain/parasthesia in dermatome and weakness of skeletal muscles in myotome; potential causes = osteoarthritis, spondylitis, spondylosis, herniated disk
spondylitis v. spondylosis
spondylitis = inflammation that causes additional bone growth @ margins of vertebral bodies; spondylosis = degenerative changes in intervertebral disks
herniated disk
occurs when the nucleus pulposus protrudes at the posterior and lateral past of the annulus fibrosis; results in the compression of the roots of spinal nerves
characteristics of cervical vertebrae
cervical vertebrae: small bodies, short spinous processes, transverse processes (for vertebral arteries), facet joints @ 45 degree angles,
characteristics of atlas v. axis
atlas (C1): posterior & anterior arches, no body, superior articular process allows 'yes motion'; axis (C2): has the dens (replaces body of atlas), pivot joint allows 'no' motion with atlas (no disk between atlas and axis)
characteristics of thoracic vertebrae
thoracic vertebrae: heart-shaped bodies, long/oblique spinous processes, costal facets (on bodies and transverse processes), facet joints @ 60 degree angles
characteristics of lumbar vertebrae
lumbar vertebrae: large kidney-shaped bodies; short horizontal spinous processes; long transverse processes; superior/inferior articular processes connected by islthmus/pars interarticularis (scotty dog)
spondylolysis & spondylolisthesis
spondylolysis = fracture of the isthmus (scotty dog) of a lumbar vertebrae (looks like a collar on the dog); spondylolisthesis = anterior displacement of the vertebral body (neck of scotty dog is extended)
components of the sacrum
sacrum = 5 fused vertebrae; median crest (from 5 spinous processes); promontory; 4 dorsal foramina (transmit dorsal rami) & 4 ventral foramina (transmit ventral rami)
muscles of the 3 layers of back muscles
superficial = trapezius, latissimus dorsi, lefator scapulae, rhomboids major/minor; intermediate = serratus posterior superior/inferior, levatores costarum (12 pairs); deep = splenius capitis/cervicis, erector spinae, tranversospinales, intervertebrals
superficial muscles of the back
trapezius, latissimus dorsi, lefator scapulae, rhomboids major/minor
intermediate muscles of the back
serratus posterior superior/inferior, levatores costarum (12 pairs
deep muscles of the back
splenius capitis/cervicis, erector spinae (illiocostalis, longissimus, spinalis), tranversospinales (semispinales, multifidus, rotatores), intervertebrals (interspinales, intertransversarii)
nerve that innervates the: trapezius
trapezius: spinal accessory nerve (CN XI)
nerve that innervates the: latissimus dorsi
latissimus dorsi: thoracodorsal nerve (one of the collateral nerves of the brachial plexus)
nerve that innervates the: levator spaculae
levator scapulae: dorsal scapular nerve (collateral nerve from brachial plexus [C5])
nerve that innervates the: rhomboid major/minor
levator scapulae: dorsal scapular nerve (collateral nerve from brachial plexus [C5])
nerves that innervate the: intermediate muscles of the back
ventral rami of spinal nerves
nerves that innervate the: deep muscles of the back
dorsal rami of spinal nerves
parts of the pectoral girdle
pectoral girdle = clavicle + scapula
what is the only location of articulation between the axial skeleton and the upper limb?
the sternoclavicular joint
what is the most common location of a fracture of the clavicle?
weakest point of clavicle = between middle 1/3 and lateral 1/3
characteristics of the glenohumeral joint
glenohumeral joint = ball & socket joint; permits flexion, extension, ad/abduction, and medial/lateral rotation; joins head of humerus with glenoid fossa of scapula
muscles involved in: elevation of the scapula
elevation of scapula = levator scapulae, upper trapezius
muscles involved in: depression of the scapula
depression of scapula = pectoralis minor, lower trapezius, latissimus dorsi
muscles involved in: protraction of scapula
protraction of scapula = serratus anterior, pectoralis minor
muscles involved in: retraction of scapula
retraction of scapula = rhomboid major/minor, middle trapezius
muscles involved in: lateral rotation of scapula (in abduction of humerus)
lateral rotation of scapula = lower serratus anterior, upper & lower trapezius
muscles involved in: medial rotation of scapula (in adduction of humerus)
medial rotation of scapula = rhomboid major/minor, levator scapulae
muscles involved in: flexion of humerus at shoulder
flexion of humerus at shoulder = pectoralis minor (clavicular), deltoid (clavicular), biceps (short head), coracobrachialis
muscles involved in: extension of humerus at shoulder
extension of humerus at shoulder = deltoid (posterior), latissimus dorsi, teres major
muscles involved in: abduction of humerus at shoulder
abduction of humerus at shoulder = deltoid (middle), supraspinatus
muscles involved in: adduction of humerus at shoulder
adduction of humerus at shoulder = pectoralis major (sternocostal), latissimus dorsi, teres minor
muscles involved in: lateral rotation of humerus at shoulder
lateral rotation of humerus at shoulder = deltoid (posterior), infraspinatus, teres minor
muscles involved in: medial rotation of humerus at shoulder
medial rotation of humerus at shoulder = pectoralis major, latissimus dorsi, deltoid (clavicular), teres major, subscapularis
muscles of the rotator cuff (and their actions)
SITS = supraspinatus (abduction), infraspinatus & teres minor (external rotation), subscapularis (internal rotation)
nerve that innervates the: pectoralis minor
pectoralis minor: medial pectoral nerve (C7 & C8, collateral nerve of brachial plexus)
nerve that innervates the: serratus anterior
serratus anterior: long thoracic nerve (C5-C7, collateral nerve of brachial plexus)
nerve that innervates the: rhomboid major/minor
rhomboid major/minor: dorsal scapular nerve (C5, collateral nerve of brachial plexus)
nerve that innervates the: deltoid
deltoid: axillary nerve (C6, lateral branch of posterior cord of brachial plexus)
nerve that innervates the: biceps brachii
biceps brachii: musculocutaneous nerve (C5-C7, proximal branch of the lateral cord, anterior division of brachial plexus)
nerve that innervates the: coracobrachialis
corachobrachialis: musculocutaneous nerve (C6-C7, proximal branch of lateral cord, anterior division of brachial plexus)
nerve that innervates the: teres major
teres major: lower subscapular nerve (C6, collateral nerve of the brachial plexus that branches from the posterior cord)
nerve that innervates the: supraspinatus
supraspinatus: suprascapular nerve (C5, arises from the upper trunk of the brachial plexus)
nerve that innervates the: pectoralis major
pectoralis major: medial & lateral pectoral nerves (C6-T1, 2 collateral branches that branch from the medial and lateral cords, respectively, of the brachial plexus)
nerve that innervates the: infraspinatus
infraspinatus: suprascapular nerve (C5-C6, arises from the upper trunk of the brachial plexus)
nerve that innervates the: teres minor
teres minor: axillary nerve (C6, posterior division fibers from the posterior cord of the brachial plexus)
nerve that innervates the: subscapularis
subscapularis: upper & lower subscapular nerves (C5-C6, collateral nerves of the brachial plexus that arise from the posterior cord)
most common direction of dislocation of the humerus
humerus is most commonly dislocated anteriorly & inferiorly from the glenohumeral joint
what nerve and artery might be damaged from a fracture of the surgical neck of the humerus?
axillary nerve & posterior circumflex humeral artery
what nerve may be lesioned as a result of an inter/supracondylar fracture of the humerus?
the median nerve
components of the elbow joints
humeroradial jointhumeroulnar jointproximal radioulnar joint
epicondylitis (definition, two main types, common names, locations)
epicondylitis: inflammation of a tendon in the elbowlateral epicondylitis (tennis elbow): common extensor tendonmedial epicondylitis (golfer's elbow): common flexor tendon
what nerve may be lesioned by a fracture of the medial epicondyle of the humerus?
the ulnar nerve
components of the wrist joint
radiocarpal jointulnocarpal jointscarpometacarpal joints
muscles involved in the flexion of the radius and ulna at the elbow
brachialisbiceps brachiibrachioradialisflexor carpi radialispronator teres
muscles involved in: the extension of the ulna and radius at the elbow joint
triceps brachii
muscles involved in: pronation of the forearm (the radius over the ulna)
pronator terespronator quadratus
muscles involved in: supination of the forearm (return of radius to anatomical position)
supinatorbiceps brachii
nerve that innervates the: brachialis
musculocutaneous nerve (C5-C6)
nerve that innervates the: biceps brachii
musculocutaneous nerve (C5-C6)
nerve that innervates the: brachioradialis
radial nerve (C5-C6)
nerve that innervates the: flexor carpi radialis
median nerve (C6-C7)
nerve that innervates the: pronator teres
median nerve (C6-C7)
nerve that innervates the: triceps brachii
radial nerve (C7-C8)
nerve that innervates the: pronator teres
median nerve (C6-C7)
nerve that innervates the: pronator quadratus
median (anterior interosseous) nerve (C8-T1)
nerve that innervates the: supinator
radial nerve, deep branch (C6-C8)
Colles' fracture (definition, consequence, common sign)
fracture of the distal radiuscan cause an avulsion of the styloid process from the radius shaftmay exhibit a dinner-fork" deformity of the forearm"
8 carpal bones (mnemonic and names, lateral to medial and proximal to distal)
mnemonic: Sometimes Lovers Try Positions / That They Cannot Handleproximal row:scaphoidlunatetriquetrumpisiform distal row:trapeziumtrapezoidcapitatehamate
what is the most commonly dislocated carpal bone? where to? what syndrome can this cause?
lunateanteriorly, into the carpal tunnelcarpal tunnel syndrome
boundaries of the carpal tunnel
posterior wall: 8 carpal bonesanterior wall: flexor retinaculum
what structures pass through the carpal tunnel?
median nerve9 tendons, from 3 flexor muscles:flexor digitorum superficialisflexor digitorum profundusflexor pollicis longus
canal of Guyon (location, structures passing through)
between pisiform bone and hook of hamate (superficial to carpal tunnel)contains: ulnar vein, artery & nerve
muscles involved in: the flexion of the hand (at the wrist)
flexors carpi ulnaris/radialisflexors digitorum superficialis/profundusflexor pollicis longuspalmaris longus
muscles involved in: extension of the hand at the wrist
Extensors... carpi ulnariscarpi radialis longus/brevisdigitorumdigiti minimipollicis longusindicus
muscles involved in: abduction (radial deviation) of hand at the wrist
extensor carpi radialis longus/brevisflexor carpi radialis
muscles involved in: adduction (ulnar deviation) of the hand at the wrist
flexor carpi ulnarisextensor carpi ulnaris
nerve that innervates the: flexor carpi ulnaris
ulnar nerve (C8)
nerve that innervates the: flexor carpi radialis
median nerve (C6-C7)
nerve that innervates the: flexor digitorum profundus
median (anterior interosseus) nerve (C8-T1)
nerve that innervates the: flexor digitorum superficialis
median nerve (C7-T1)
nerve that innervates the: flexor pollicus longus
median (anterior interosseus) nerve (C8-T1)
nerve that innervates the: palmaris longus
median nerve (C7-C8)
nerve that innervates the: extensor carpi ulnaris
radial nerve, deep branch (C7-C8)
nerve that innervates the: extensor carpi radialis longus
radial nerve (C6-C7)
nerve that innervates the: extensor carpi radialis brevis
radial nerve, deep branch (C6-C7_
nerve that innervates the: extensor digitorum
radial nerve, deep branch (C6-C8_
nerve that innervates the: extensor digiti minimi
radial nerve, deep branch (C7-C8)
nerve that innervates the: extensor pollicis longus
radial nerve, deep branch (C7-C8)
nerve that innervates the: extensor indicis
radial nerve, deep branch (C7-C8)
3 joints of each finger (and the bones involved)
MP: metacarpophalangeal joint (metacarpal bone + proximal phalanx)PIP: proximal interphalangeal joint (proximal + middle phalanges)DIP: distal interphalangeal joint (middle + distal phalanges)
main functional difference between the metarcarpophalangeal joints and the interphalangeal joints
MP = condyloid joints (allow flexion/extenstion AND adduction/abduction)IP = hinge joints (ONLY allow flexion/extension)
how many joints does the thumb have?
only 2: 1) MP & 2) IP(because there are only two phalanges bones in the thumb, not 3 like the fingers)
what muscle is involved in:flexion of the fingers at the MP, PIP and DIP joints?
flexor digitorum profundus
what muscle is involved in:flexion of the fingers at the MP and PIP joints, only?
flexor digitorum superficialis 
what muscles are involved in:flexion of the fingers at the MP joints, only? 
lumbricalsinterossei
what muscle is involved in:flexion of the pinky finger at the carpometacarpal AND metacarpophalangeal joints?
flexor digiti minimi
what muscle is involved in:flexion of the pinky finger at the carpometacarpal joint only?
opponens digiti minimi
what muscle is involved in:extension of the index, middle & ring finger at the metacarpophalangeal joint?
extensor digitorum
what muscle is involved in:extension of the index finger at the at the metacarpophalangeal joint?
extensor indicus
what muscle is involved in:extension of the pinky finger at the metacarpophalangeal joint?
extensor digiti minimi
what muscles are involved in:extension of all the fingers at the interphalangeal joints?
lumbricalsinterossei
what muscle is involved in:abduction of all fingers (except the pinky) at the metacarpophalangeal joints?
dorsal interossei
what muscle is involved in:abduction of the pinky finger at the metacarpophalangeal joint?
abductor digiti minimi
what muscle is involved in:adduction of all fingers (except the pinky) at the metacarpophalangeal joints?
palmar interossei
what muscle is involved in:opposition of the pinky finger at the carpometacarpal joint?
opponens digiti minimi
what muscle is involved in:flexion of the thumb at ALL joints (especially the interphalangeal)?
flexor pollicis longus
what muscle is involved in:flexion of the thumb at both the carpometacarpal and the metacarpophalangeal joint?
flexor pollicis brevis
what muscle is involved in:flexion of the thumb at the carpometacarpal joint only?
opponens pollicis
what muscle is involved in:extension of the thumb at all joints?
extensor pollicis longus
what muscle is involved in:extension of the thumb at the carpometacarpal and metacarpophalangeal joints only?
extensor pollicis brevis
what muscle is involved in:abduction of the thumb at the carpometacarpal joint only?
abductor pollicis longus
what muscle is involved in:abduction of the thumb at both the carpometacarpal and metacarpophalangeal joints?
abductor pollicis brevis
what muscle is involved in:adduction of the thumb at the carpometacarpal and metacarpophalangeal joints?
adductor pollicis
what muscle is involved in:opposition of the thumb at the carpometacarpal and metacarpophalangeal joints?
opponens pollicis
nerves that innervates the:flexor digitorum profundus
anterior interosseus [median] nerve (to index & middle fingers)ulnar nerve (to ring and pinky fingers)
nerve that innervates the:flexor digitorum superficialis
median nerve (C8-T1)
nerves that innervates the:lumbricals of the hand
middle/index fingers: median nervering/pinky: ulnar nerve
nerve that innervates the:interossei of the hand
ulnar nerve, deep branch (C8-T1)
nerve that innervates the:flexor digiti minimi
ulnar nerve, deep branch
nerve that innervates the:opponens digiti minimi
ulnar nerve, deep branch
nerve that innervates the:extensor digitorum of the hand
radial nerve, deep branch (C6-C8)
nerve that innervates the:extensor indicis
radial nerve, deep branch (C7-C8)
nerve that innervates the:extensor digiti minimi
radial nerve, deep branch (C7-C8)
nerve that innervates the:abductor digiti minimi of the hand
ulnar nerve, deep branch (C8-T1)
nerve that innervates the:opponens digiti minimi
ulnar nerve, deep branch (C8-T1)
nerve that innervates the:flexor pollicis longus
median (anterior interosseus) nerve (C8-T1)
nerve that innervates the:flexor pollicis brevis
median nerve, recurrent branch
nerve that innervates the:opponens pollicis
median nerve, recurrent branch (C8-T1)
nerve that innervates the:extensor pollicis longus
radial nerve, deep branch (C7-C8)
nerve that innervates the:extensor pollicis brevis
radial nerve, deep branch (C7-C8)
nerve that innervates the:abductor pollicis longus
radial nerve, deep branch (C7-C8)
nerve that innervates the:abductor pollicis brevis
median nerve, recurrent branch (C8-T1)
nerve that innervates the:adductor pollicis
ulnar nerve, deep branch (C8-T1)
nerve that innervates the:opponens pollicis
median nerve, recurrent branch (C8-T1)
anatomic snuffbox
portion of the posterolateral portion of the wrist that is bounded by the extensor pollicus brevis and the abductor pollicis longus importance: overlies the scaphoid bone; fracture in scaphoid leads to pain over anatomical snuffboxradial artetry passes through snuffbox
what is the most commonly fractured bone in the wrist?
the scaphoid bone(fracture causes pain over anatomical snuffbox and can lacerate part of the radial artery)
at what point does the subclavian artery become the axillary artery?
as it passes the lateral border of the first rib
main artery that branches off of the subclavian artery (and the two arteries that it splits into)
the thyrocervical trunk, which splits into:suprascapular arterytransverse cervical artery
muscles supplied by: suprascapular artery
supraspinatusinfraspinatus
muscles supplied by:transverse cervical artery (superficial and deep branches)
superficial branch: trapeziusdeep branch (aka dorsal scapular artery): rhomboids & levator scapulae
branches of the transverse cervical artery
superficial branch of the transverse cervical arterydorsal scapular artery (aka deep branch of the transverse cervical artery)
the 1-2-3" of the axillary artery"
3 segments of the axillary artery (proximal to distal):between 1st rib & pectoralis minor: 1 branch coming off (superior thoracic artery)underneath pectoralis minor: 2 branches (thoracromial & lateral thoracic arteries)between pectoralis minor and teres major tendon: 3 branches (subscapular artery, posterior & anterior circumflex humeral arteries)
superior thoracic artery (location & muscles supplied)
branches off the 1st segment of the axillary arterysupplies a) the 1st two intercostal spaces and b) the serratus anterior
thoracromial artery (location & structures supplied)
the first branch of the 2nd segment of the axillary arterysupplies the anterior wall of the axilla: pectoral musclesdeltoidclavicleacromioclavicular joint
lateral thoracic artery (location & structures supplied)
the second branch of the 2nd segment of the axillary arterycourses with the long thoracic nervesupplies: serratus anterior, pectoral muscles the breast
subscapular artery (location, branches and structurest they supply)
largest branch of the axillary artery (1st branch of 3rd segment of the axillary)branches:circumflex scapular artery: supplies teres major/minor & infraspinatusthoracodorsal artery: supplies the latissimus dorsi
circumflex scapular artery (location & structures supplied)
branches off the subscapular artery (from the axillary artery)supplies: teres major/minorinfraspinatus
thoracodorsal artery (location & structures supplied)
branch off the subscapular artery (from the axillary artery)supplies the latissiumus dorsi
posterior circumflex artery (location & structures supplied)
2nd branch off the 3rd segment of the axillary arterycourses with the axillary nerve through the quadrangular spacesupplies: deltoidteres major/minorlong head of triceps
anterior circumflex humeral artery (location & structures supplied)
3rd and last branch of the 3rd segment of the axillary arterysupplies muscles in the anterior arm
potential anastamoses that can circumvent an occlusion of the axillary artery (1st or 2nd part)
anastomoses can occur between:1) the circumflex scapular and thoracodorsal branches of the subscapular artery, and2) suprascapular, dorsal scapular and posterior intercostal arteries
at what point does the axillary artery become the brachial artery?
at the lower border of teh teres major tendon
main artery branching off the brachial artery
the profunda brachial artery (aka deep brachial artery)
profunda brachial artery (location & structures supplied)
branches off the brachial arterycourses with the radial nerve around the shaft of the humerussupplies triceps brachii and provides collateral circulation around the elbow
what is Volkmann's ischemic contracture?
Volkmann's ischemic contracture: compression of the brachial artery (perhaps from a supercondylar fracture of the humerus) causes ischemia of the foream and handpatients present with severely flexed hand and fingers
what is Dupuytren's conctracture?
Dupuytren's contracture: fibrosis/shortening of the palmar aponeurosis compresses the flexor tendonspatients present with flexion of the ring and pinky fingers
the brachial artery splits into which two arteries?
radial artery (laterally)ulnar artery (medially)
location at which the brachial artery splits into the radial and ulnar arteries?
the cubital fossa
ulnar artery (location & structures supplied)
arises from the brachial artery at the cubital fossasupplies: the medial side of the forearmthe hand
branches of the ulnar artery
common interosseus arterysuperficial (palmar) arch deep branch
common interosseus artery (location & structures supplied)
arises from ulnar artery in cubital fossabranches into a) anterior interosseus artery (anterior forearm), andb) posterior interosseus artery (posterior forearm)
superficial palmar arch (location & structures supplied)
arises from the ulnar arterysupplies the hand and digits
radial artery (location & structures supplied)
branches laterally from the brachial artery at the cubital fossasupplies the lateral side of the forearm and the handbranches: superficial, deep palmar arch
primary veins draining the upper limb
cephalic vein (lateral aspect)basilic vein (medial aspect)brachial vein (central)
gradient of innervation in the brachial plexus (basic terms)
proximal to distal gradient: superior rami innervate proximal musclesinferior rami innervate distal muscles
basic organization of the brachial plexus
5 roots (C5-T1)3 trunks (superior, middle, inferior)6 divisions (3 anterior, 3 posterior)3 cords (lateral, posterior, anterior)10 collateral branches5 terminal branches
in the upper limb, generally, anterior muscles act as....
flexors(innervated by ANTERIOR DIVISION fibers: musculocutaneous, ulnar, median lateral and medial pectoral nerves)
in the upper limb, generally, posterior muscles at as...
extensors(inntervated by POSTERIOR DIVISION fibers: axillary, radial, upper, middle, and lower subscapular nerves)
preplexus injuries
affect ventral rami or trunks proximal to most of the brachial plexus, which means they have a much more widespread effects than more distal injuries
what is Erb-Duchenne syndrome?
Erb-Duchenne syndrome is cuased by a lesion to the C5 & C6 ventral rami in the superior trunk of the brachial plexusmainly affects proximal musculature in the upper limbpatients often present with a waiter's tip" position (arm adducted extended and medially rotated)"
what is Klumpke's paralysis?
Klumpke's paralysis is caused by compression of the C8 & T1 ventral rami in the inferior trunk of the brachial plexus (perhaps because of a pancoast tumor in the apical lung)mainly affects distal muscles in the upper limb (intrinsic muscles of hand)patients can present with ape hand" and "claw hand or may have difficulty making a fist
5 terminal branches of the brachial plexus
anterior division (lateral to medial): musculocutaneous, median & ulnar nervesposterior division (lateral to medial): axillary & radial nerves
10 collateral branches off the brachial plexus
long thoracicdorsal scapularsuprascapularlateral pectoralsubscapular: upper, middle (thoracodorsal) & lowermedial pectoralmedial brachial cutaneousmedial antebrachial cutaneous
structures innnervated by the:suprascapular nerve
supraspinatus and infraspinatus muscles
structures innnervated by the:lateral pectoral nerve
pectoralis major (clavicular head)
structures innnervated by the:medial pectoral nerve
pectoralis minor & pectoralis minor
structures innnervated by the:medial brachial cutaneous nerve
skin on the medial aspect of the arm
structures innnervated by the:medial antebrachial cutaneous nerve
skin on the medial aspect of the forearm
structures innnervated by the:upper subscapular nerve
the subscapularis muscle
structures innnervated by the:middle subscapular (thoracodorsal) nerve
the latissimus dorsi
structures innnervated by the:lower subscapular nerve
subscapularis and teres major
structures innnervated by the:dorsal scapular nerve
levator scapulaerhomboid major/minor
structures innnervated by the:long thoracic nerve
serratus anterior
lesions to the long thoracic nerve can cause...
winging" of the scapula because the serratus anterior cannot hold the vertebral border of the scapula flat against the back"
lesions of the suprascapular nerve can cause...
shoulder pain, weakness in abduction and lateral rotation of the arm at the shoulder
lesions of the thoracodorsal nerve can cause...
weakness of the latissimus dorsi, resulting in difficulty in elevating the trunk (like in doing a pull-up) and may have difficult using a crutch
lesions of the musculocutaneous nerve can cause...
weakness in flexion of the forearm at the elbow and in supination of the forearm
structures innnervated by the:median nerve
the superficial muscles in the anterior forearm: flexor carpi radialis,palmaris longus,flexor digitorum superficialis, &pronator teresthe thenar muscles(innervates all muscles in anterior forearm EXCEPT: brachioradialis, flexor carpi ulnaris & part of flexor digitorum profundus)
structures innnervated by the:anterior interosseus nerve
lateral half of the flexor digitorum profundusflexor pollicis longuspronator quadratus
structures innnervated by the:recurrent branch of the median nerve
3 thenar muscles
structures innnervated by the:muscular branches ofthe median nerve
the lumbricals of the index and middle fingers
structures innnervated by the:common palmar digital and proper digital cutaneous nerves (branches of the median nerve)
palmar aspects & sides of the thumb, index, middle fingers & half of ring finger
structures innnervated by the:palmar cutaneous branch of the median nerve
skin of the lateral palm up to the middle of the ring finger
branches of the median nerve
common interosseus nerve (anterior & posterior branches)recurrent branchcommon palmar digital nervesproper digital cutaneous nervespalmar cutaneous branch
cutaneous innervation of the hand
radial nerve (superficial): lateral 1/2 of dorsal sidemedial nerve: lateral 1/2 of palmar side (& index, middle & 1/2 of ring fingertips)ulnar nerve: medial dorsal/palmar hand (pinky & 1/2 of ring)
lesions to the median nerve in the carpal tunnel can cause...
carpal tunnel syndrome: numbness and pain, particularly at night over the palmar aspects of the thub, index and middle fingers
lesions to the median nerve proximal to the cubital fossa can cause...
(often caused by a supracondylar fracture of the humerus)altered sensation in the lateral part of the handweakness in pronation and ability to flex thumb and middle/index fingerspatients often present with hand of benediction""
lesions to the anterior interosseus nerve can cause...
weakness of pronation of the forearmweakness in flexion of the index & middle fingers at ateh DIP joints
branches of the ulnar nerve
palmar cutaneous branchdorsal cutaneous branchsuperficial branchdeep branch
structures innnervated by the:ulnar nerve
1½ muscles in the anterior forearm: flexor carpi ulnaris and medial 1/2 of flexor digitorum profundus
structures innnervated by the:palmar/dorsal cutaneous branches of the ulnar nerve
palmar: medial aspect of the palm of the handdorsal: medial dorsum of hand and fingers
structures innnervated by the:superficial branch of the ulnar nerve
palmaris brevisskin of the medial side of the palm and dorsum of the hand
structures innnervated by the:deep branch of the ulnar nerve
3 muscles of the hypothenar eminencelumbricals of teh ring and little fingeradductor pollicis7 interosseus muscles (dorsal and palmar)
lesions to the ulnar nerve at the wrist can cause...
ulnar claw hand of the ring and little fingers (b/c/o weakness of medial 2 lumbricals that flex at the MP joints and extend at the interphalangeal joints)(often occurs by fracture of the hook of hamate) 
lesions to the ulnar nerve at the elbow can cause...
ulnar claw hand (pinky & little fingers)weakness in flexion of the distal interphalangeal joints or ring and little fingerspain/paresthesia in ring and pinky fingers(most often occurs at the spot where the ulnar nerve passes the medial epicondyle)
structures innnervated by the:axillary nerve
deltoidteres minorskin of arm covering the attachment of the deltoid to the humerus
lesions to the axillary nerve can cause...
weakness in abduction of the arm at the shoulderaltered sensation of the skin over the deltoid muscle
branches of the radial nerve
in the proximal forearm, the radial nerve splits into:superficial cutanenous branch, anddeep muscular branch
structures innnervated by the:radial nerve
3 heads of the triceps brachiibrachioradialisextensor carpi radialis longusskin of the posterior arm
structures innnervated by the:superficial branch of the radial nerve
skin over the lateral forearmskin of the dorsal lateral part of hand
structures innnervated by the:deep branch of the radial nerve
muscles of the posterior forearm (mainly extensors): supinator,extensor digitorumextensor carpi radialis brevisextensor carpi ulnarisextensors pollicis longus/brevisabductor pollicis longusextensor digiti minimiextensor indicis
lesions of the radial nerve at the humerus can cause...
wrist drop": weakness in extension of the hand at the wristweakened supination of forearm"
components of the pelvic girdle
iliumischiumpubis(all join at acetabulum)
hip joint (type, parts, movements that occur)
ball-and-socket jointcomponents: bones: head of femur and acetabulumligaments: iliofemoral, pubofemoral & ischiofemoralmovements: flexion/extension, ab/adduction, medial/lateral rotation
fracture of the neck of the femur can cause...
avascular necrosis by rupturing the medial circumflex femoral artery (the sole artery supplying blood to the head of the femur)
direction in which hip dislocations most commonly occur
posterior direction (head of femur moves posteriorly)
muscles involved in:flexion of the femur at the hip
iliacus & psoas majorrectus femorissartoriustensor fasciae lataepectineusadductors longus/brevis
muscles involved in:extension of the femur at hip
gluteus maximussemimebranosussemitendinosusbiceps femoris (long head)adductor magnus (hamstring part)
muscles involved in:adduction of the femur at the hip
adductors longus, brevis, & magnusgracilispectineus
muscles involved in:abduction of femur at the hip
gluteus medius & minimustensor fasciae latae
muscles involved in:medial rotation of femur at the hip
gluteus minimiusgluteus medius, anterior fibers
muscles involved in:lateral rotation of the femur at the hip
gluteus maximussartoriusobturator internus/externus gemellus superior/inferiorquadratus femorispiriformis
nerve that innervates the:iliacus
lumbar ventral rami (L2-L3)
nerve that innervates the:psoas major
lumbar ventral rami (L2-L3)
nerve that innervates the:rectus femoris
femoral nerve (L2-L4)
nerve that innervates the:sartorius
femoral nerve (L2-L3)
nerve that innervates the:tensor fasciae latae
superior gluteal nerve (L4-S1)
nerve that innervates the:pectineus muscle
femoral nerve (L2-L3)
nerve that innervates the:obturator longus
obturator nerve (L2-L4)
nerve that innervates the:adductor brevis
obturator (L2-L4)
nerve that innervates the:adductor magnus
obturator nerve (L2-L4)
nerve that innervates the:gluteus maximus
inferior gluteal nerve (L5-S2)
nerve that innervates the:semimembranosus
sciatic nerve, tibial part (L5-S1)
nerve that innervates the:semitendonosus
sciatic nerve, tibial part (L5-S2)
nerve that innervates the:biceps femoris, long head
sciatic nerve, tibial part (S1-S2)
nerve that innervates the:gluteus medius & minimus
superior gluteal nerve (L4-S1)
nerve that innervates the:obturator internus
nerve to teh obturator internus (L5-S2)
nerve that innervates the:superior gemellus
nerve to the obturator internus (L5-S2)
nerve that innervates the:obturator externus
obturator nerve (L3-L4)
nerve that innervates the:quatratus femoris
nerve to the quadratus femoris (L4-S1)
nerve that innervates the:inferior gemellus
nerve to the quadratus femoris
nerve that innervates the:piriformis
nerve to the piriformis (L5-S2)
knee joint (type, parts, movements)
modified hinge jointbones: condyles of femur & tibial plateausligaments: patellar, oblique popliteal, tibial & fibular (medial & lateral) collateral, anterior & posterior cruciate ligamentsmovements: flexion/extension, extension, rotation, gliding
patellar ligament
connects the patella to the tibial tuberosity
oblique popliteal ligament
part of the semimembranosus tendonstrengthens the posterior part of the knee joint capsule
fibular collateral ligament
aka lateral collateral ligamentconnects the lateral epicondyle of the femur to the head of the fibula
tibial collateral ligament
aka medial collateral ligamentconnects the medial epicondyle of the femur to the medial aspect of the tibia
muscles involved in:flexion of the leg at the knee
semimembranosussemitendinosusbiceps femoris (long & short heads)gracilissartoriuspopliteusgastrocnemius
muscles involved in:extension of the leg at the knee
quadriceps femoris: vastus medialis/intermedius/lateralisrectus femoris
muscles involved in:lateral rotation of the leg at the knee
biceps femoris
muscles involved in:medial rotation of the leg at the knee
popliteus ('unlocks' extended knee)semimembranosussemitendinosusgracilissartorius
nerve that innervates the:biceps femoris, long head
sciatic nerve, tibial part (S1-S2)
nerve that innervates the:biceps femoris, short head
sciatic nerve, common peroneal (L5-S2)
nerve that innervates the:gracilis
obturator nerve (L2-L4)
nerve that innervates the:popliteus
tibial nerve (L4-S1)
nerve that innervates the:gastrocnemius
tibial nerve (S1-S2)
nerve that innervates the:quadriceps femoris (vastus lateralis/intermedius/medialis, rectus femoris)
femoral nerve (L2-L4)
anterior cruciate ligament
aka ACLthe APEX" ligament: attaches to tibia Anteriorlycourses Posteriorly and EXternallyprevents anterior displacement of the tibia on the femur"
posterior cruciate ligament
aka PCLthe PAIN" ligament: attaches to tibia Posteriorlycourses Anteriorly and INternallyprevents the posterior displacement of tibia on femur"
medial & lateral menisci
intracapsular, fibrous shock-absorbers of the kneemedial: shaped like a Clateral: shaped like an O
the terrible triad" of knee injuries"
tibial (medial) collateral ligamentmedial meniscusanterior cruciate ligament (ACL)
joints that make up the ankle
talocrural joint (tibia/fibula & talus)subtalar (talus & calcaneus)transverse tarsal joints
talocrural joint (type, components, movement)
hinge jointbones: a) trochlea of talus and b) lateral maleolus of fibula and medial maleolus of tibialigaments: deltoid (medial) & lateralmovement: dorsiflexion (extension) and plantar flexion (flexion)
components of deltoid (medial) ligament of ankle
4 parts (stronger than lateral ligament)1 & 2) anterior & posterior tibiotalar ligaments3) tibionavicular ligament4) tibiocalcaneal ligament
coponents of the lateral ligament of the ankle
3 components (weaker than deltoid ligament)1 & 2) anterior & posterior taolofibular ligaments3) calcaneofibular ligament
which are more common: eversion ankle sprains or inversion ankle sprains?
inversion ankle sprains = more common (lateral ligament of ankle is weaker than medial ligment of ankle)
subtalar joing (type, components, movement)
ball-and-socket jointinvolves talus & calcaneusmovement: supination (inversion) & pronation (eversion)
transverse tarsal joints (type, components, movements)
components: talus & navicular bonecalcaneus & cuboid bonemovement: contributes to inversion and eversion
muscles involved in:plantar flexion of the foot at the ankle
gastrocnemiussoleusplantaristibialis posteriorflexor digitorum longusflexor hallicus longusperoneus (fibularis) longus/brevis
muscles involved in:dorsiflexion of the foot at the ankle
tibialis anteriorextyensor hallicis longusextensor digitorum longusperoneus tertius
muscles involved in:inversion of the foot at the ankle
tibialis anteriorextensor hallicis longustibialis posterior
muscles involved in:eversion of the foot at the ankle
peroneus longus/brevis/tertius
nerve that innervates the:gastrocnemius
tibial nerve (S1-S2)
nerve that innervates the:soleus
tibial nerve (S1-S2)
nerve that innervates the:plantaris muscle
tibial nerve (L5-S1)
nerve that innervates the:tibialis posterior
tibial nerve (L5-S1)
nerve that innervates the:flexor digitorum longus
tibial nerve (L5-S1)
nerve that innervates the:flexor hallucis longus
tibial nerve (L5-S2)
nerve that innervates the:peroneus longus
superficial peroneal nerve (L5-S1)
nerve that innervates the:peroneus brevis
superficial peroneal nerve (L5-S1)
nerve that innervates the:tibialis anterior
deep peroneal nerve (L4-L5)
nerve that innervates the:extensor hallucis longus
deep peroneal nerve (L5-S1)
nerve that innervates the:extensor digitorum longus
deep peroneal nerve (L4-S1)
nerve that innervates the:peroneus tertius
deep peroneal nerve (L4-S1)
path of the femoral artery
begins at the inguinal ligament (as a continuation of the external iliac artery)courses: through femoral triangleends as it courses through the adductor canal, where it becomes the popliteal artery
deep femoral artery
branches off the femoral arterygives rise to the lateral and medial circumflex arteries (supply head/neck of femur)4 perforating arteries that supply the medial thigh
cruciate anastomosis of the posterior thigh
provide collateral circulation of the lower limb in case the femor artery becomes occludedoccurs among: medial/lateral circumflex femoral arteriesinferior gluteal arteryfirst perforating artery
muscles involved in:flexion of all joints of the toes
flexors hallucis/digitorum longusquadratus plantae (aka flexor accessorius)
muscle(s) involved in:flexion of the tarsometatarsal & proximal interphalangeal joints (toes 2-5)
flexor digitorum brevis
muscle(s) involved in:flexion of the tarsometatarsal joints of toes 1 & 5
flexor hallucis brevisflexor digiti minimi brevis
muscle(s) involved in:flexion of toes 2-5
lumbricals (1-4)interossei
muscle(s) involved in:extension of toes at all joints
extensor digitorum longus
muscle(s) involved in:extension of toes 2-4 at all joints
extensor digitorum brevis
muscle(s) involved in:extension of the big toe at all joints
extensor extensor hallucis longus
muscle(s) involved in:extension of the big toe at the tarsometatarsal joints only
extensor hallucis brevis
muscle(s) involved in:extension of toes 2-5 at the interphalangeal joints only
lumbricals
muscle(s) involved in:abduction of big toe at the metatarsophalangeal joint
abductor hallucis
muscle(s) involved in:abduction of toes 2-4 at the metatarsophalangeal joints
dorsal interossei
muscle(s) involved in:abduction of the pinky toe at the metatarsophalangeal joint
abductor digiti minimi
muscle(s) involved in:adduction of the big toe at the tarsometatarsal joint
adductor hallucis
muscle(s) involved in:adduction of toes 3-5 at the tarsometatarsal joints
plantar interossei
nerve that innervates the:flexor hallucis longus
tibial nerve (L5-S1)
nerve that innervates the:flexor digitorum longus
tibial nerve (L5-S1)
nerve that innervates the:quadratus plantae
lateral plantar nerve (S1-S2)
nerve that innervates the:flexor digitorum brevis
medial plantar nerve (L5-S1)
nerve that innervates the:flexor hallucis brevis
medial plantar nerve (L5-S1)
nerve that innervates the:flexor digiti minimi brevis
lateral plantar nerve (S1-S2)
nerve that innervates the:first lumbrical
median plantar nerve (L5-S1)
nerve that innervates the:2nd thru 4th lumbricals
lateral plantar nerve (S1-S2)
nerve that innervates the:plantar interossei
lateral plantar nerve (S1-S2)
nerve that innervates the:extensor digitorum longus
deep peroneal nerve (L4-S1)
nerve that innervates the:extensor digitorum brevis
deep peroneal nerve (L5-S1)
nerve that innervates the:extensor hallucis longus
deep peroneal nerve (L5-S1)
nerve that innervates the:extensor hallucis brevis
deep peroneal nerve (L5-S1)
nerve that innervates the:abductor hallucis
medial plantar nerve (L5-S1)
nerve that innervates the:dorsal interossei
lateral plantar nerve (S1-S2)
nerve that innervates the:abductor digiti minimi
lateral plantar nerve (S1-S2)
nerve that innervates the:adductor hallucis
lateral plantar nerve (S1-S2)
popliteal artery
originates as the femoral artery passes through the adductor hiatuscourses through popliteal fossagives rise to 5 genicular arteries ends at the inferior border of the popliteus when it splits into the anterior and posterior tibial arteries
arteries contributing to collateral circulation around the knee
5 genicular branches of the popliteal arteriesdescending genicular branch of the femoral arterydescending branch of the lateral circumflex arteryanterior recurrent branch of the anterior tibial artery
anterior tibial artery
branches off the popliteal arterycourses anteriorly with the deep peroneal nerve, passing between tibia and fibula proximal to the interosseus membranesupplies the anterior compartment of the legbecomes the dorsalis pedis artery at the ankle
where can the dorsalis pedis pulse be felt?
at the dorsal artery of teh foot, lateral to the tendon of the extensor halucis longus
posterior tibial artery
arises from the popliteal artery after the anterior tibial artery splits offcourses through the posterior compartment of the leg with the tibial nervesupplies the posterior compartment of the leggives rise to the peroneal artery, which branches off laterallypasses into the foot behind the medial malleolus and divides into the medial and lateral plantar arteries
branches of the internal iliac artery that supply the gluteal region
superior gluteal arteryinferior gluteal arteryobturator artery
superior gluteal artery (path, structures supplied)
branches from internal iliac artery courses with superior gluteal nerve, superior to the piriformispasses through greater sciatic foramensupplies the gluteus maximus/medius/minimus
inferior gluteal artery (path, structures supplied)
branches off the internal iliac arterycourses along with the inferior gluteal nerve, inferior to the piriformispasses through the greater sciatic foramensupplies the gluteus maximus, lateral rotators of the femur and parts of the hamstrings
venous drainage of the lower limb: superficial and deep vessels
superficial: great and small saphenous veinsdeep: veins that course with arteries of the same name
lumbar plexus
formed by the ventral rami of L1-L4 ventral ramilocated on the posterior abdominal wall and greater pelvisanterior division: becomes the obturator nerveposterior division: becomes the femoral nerve
what nerve does the anterior division of the lumbar plexus become?
the obturator nerve
what nerve does the posterior division of the lumbar plexus become?
the femoral nerve
lumbosacral plexus
formed by the ventral rami of L4-S3 spinal nerveslocated in the lesser pelvis2 parts: anterior division: tibial nerveposterior division: common fibular/peroneal nerve
what nerve does the anterior division of the lubosacral plexus become?
the tibial nerve
what nerves does the posterior division of the lumbosacral plexus become?
the common fibular/peroneal nervealso: superior and inferior gluteal nerves
terminal nerves of the lumbar plexus
femoral nerve (from posterior division of lumbar plexus)obturator nerve (from anterior division of lumbar plexus)
femoral nerve
arises from the posterior division of the lumbar plexuscourses with the psoas majorpasses into the anterior thigh posterior to the inguinal ligamentgives rise to the saphenous nerveinnervates: quadriceps femoris, iliopsoas, sartorius and pectineus
saphenous nerve
the longest branch of the femoral nervearises from the femoral nerve as it passes through the adductor canalcourses through the great saphenous veininnervates the skin of the medial side of the leg and foot
lesions to the femoral nerve in the abdomen can cause...
weakness in:flexion of the thigh at the hipextension of the leg at the knee
lesions to the saphenous nerve can cause...
pain and paresthesia in the skin of the medial aspect of the leg and foot
obturator nerve
arises from anterior division fibers of the lumbar plexuscourses anteriorly and inferiorly in the lesser pelvis  passes through the obturator foramen and into the medial thighinnervates: adductor longus/brevis/magnus, gracilis, obturator externus
lesions to the obturator nerve in the pelvis can cause...
weakness in adduction of the thigh at the hipparesthesia in the skin of the medial thigh
5 collateral nerves of the lumbar plexus (somtimes i imagine gorgeous lovers)
subcostal nerveiliohypogastric nerveilioinguinal nervegenitofemoral nervelateral femoral cutaneous nerve
lesions to the lateral femoral cutaneous nerve can cause...
pain and paresthesia in the anterolateral thigh
6 terminal nerves of the lumbosacral plexus
superior gluteal nerveinferior gluteal nervetibial nervecommon fibular nervesuperficial fibular nervedeep fibular nerve
superior gluteal nerve
arises from poterior division fibers of the lumbosacral plexuscourses with the superior gluteal artery through the greater sciatic foramen superior to piriformis muscleinnervates the gluteus medius/minimus & tensor fasciae latae
lesions to the superior gluteal nerve can cause...
weakness in abduction of the thigh at the hip (causing a waddling gait)
inferior gluteal nerve
arises from posterior division fibers in the lumbosacral plexuscourses with the inferior gluteal artery through the greater sciatic foramen inferior to the piriformis muscleinnervates the gluteus maximus
lesions to the inferior gluteal nerve can cause...
weakness in lateral rotation and extension of the thigh at the hip (difficulty climbing stairs)causes a gluteus maximus gait""
tibial nerve
arises from anterior division fibers of the lumbosacral plexuspasses through the greater sciatic foramen inferior to the piriformiscourses through the posterior thigh with the common fibular nerve (as the sciatic nerve)separates from fibular nerve at the superior border of the popliteal fossacourses through the posterior legpasses through the plantar tunnel and divides into the medial and lateral plantar nerves
structures innervated by the:medial plantar nerve
4 muscles in the sole of the foot:flexor digitorum brevisflexor hallucis brevisabductor hallucisfirst lumbrical
structures innervated by the:lateral plantar nerve
quadratus plantaeflexor digiti minimi brevisplantar/dorsal interosseilumbricals 2-4abductor digiti minimiadductor hallucis
what nerve can be lesioned by an intramuscular injection into the gluteus maximus OR a posterior dislocation of the femur in the hip?
the sciatic nerve
lesions of the tibial nerve in a) the gluteal region or b) the ankle can cause...
a) gluteal lesion: weakness of flexion of leg at knee & plantar flexion of footb) ankle lesion: pain/paresthesia in sole of foot
common fibular (peroneal) nerve
arises from posterior division fibers of the lumbosacral plexuscourses with the tibial nerve as the sciatic nerve through the posterior thighseparates from the tibial nerve at the superior border of the popliteal fossaspirals laterally around the neck of the fibulasplits into deep and superficial branches, which innervate the anterior and lateral compartments of the leg, respectively
what is the most frequently lesioned nerve in the lower limb?
the common fibular nerve (as it passes around the neck of the fibula)
lesions to the common fibular nerve can cause...
footdrop" from a loss of dorsiflexion and eversion at the ankle associated with a steppage gait (raising foot high up off the ground slapping it on the ground)"
superficial fibular (peroneal) nerve
arises when the common fibular nerve bifurcates in the legcourses through the lateral compartment of the leginnervates: the fibularis (peroneus) longus and brevis, and the skin of the lateral leg and dorsum of the foot
lesions to the superficial fibular (peroneal) nerve can cause...
pain and paresthesia in the dorsum of the foot
deep fibular (peroneal) nerve
arises when the common fibular nerve bifurcates in the legcourses with the anterior tibial artery through the anterior compartment of the leginnervates the muscles of the anterior leg and dorsum of foot: tibialis anteriorextensor hallucis longus/brevisextensor digitorum longus/brevisfibularis (peroneus) tertius
lesions to the deep fibular (peroneal) nerve can cause...
footdrop and paresthesia in the skin of the webbed space between the big toe and 2nd toe
6 collateral nerves of the lumbosacral plexus
sural nervenerve to the quadratus femorisnerve to the obturator internusposterior femoral cutaneous nervenerve to the piriformisperforating cutaneous nerve
sural nerve
arises from contributing fibers of the tibial and common fibular nervescourses with the small saphenous vein in the posterior leginnervates: skin of posterior leg and lateral aspect of foot
nerve to the quadratus femoris muscle
arises from anterior fibers of the lumbosacral plexus (L4-S1)enters gluteal region after passing thorugh the greater sciatic forameninnervates: inferior gemellus and quadratus femoris
nerve to the obturator internus muscle
arises from anterior fibers of the lumbosacral plexus (L5-S2)enters gluteal region after passing through the greater and lesser sciatic foraminainnervates the obteratur internus (and possibly the inferior gemellus)
posterior femoral cutaneous nerve
arises from anterior and posterior division fibers of the lumbosacral plexus (S1-S3)innervates the skin of the posterior thigh and upper calf
nerve to the piriformis muscle
arises from S1-S2 ventral rami in the lumbosacral plexusinnervates the piriformis muscle
perforating cutaneous nerve
arises from S2-S3 ventral rami in the lumbosacral plexusinnervates the skin covering the ischioanal fossa and the gluteal region near the anal canal