brachial plexus Flashcards
innervates serratus anterior m. (hold scapula to thorax)
long thoracic nerve
SALT: Serratus Anterior Long Thoracic
innervates infraspinatous + supraspinatous m.
suprascapular nerve
innervates pectoralis major m.
lateral pectoral nerve
innervates subscapularis m.
upper subscapular nerve
innervates latismus dorsi m.
thoracodorsal nerve.
innervates teres major
lower subscapular nerve
major flexors of forearm+ supinators:
biceps m., coracobrachialis m., brachialis m. (flexes + supinates forearm)
motor innervation of musculocutaneous nerve
deltoid (abducts shoulder)
long head of triceps (extends forearm)
teres minor m. (externally rotates arm)
motor innervation of axillary nerve
motor innervation of radial nerve
BEST: many of extensors + supinators
Brachioradialis (FLEXES forearm, supinates, pronates)
Extensor carpi radialis longus (extend wrist), Extensor digitorum, extensor pollicis longus + other extensors (extends wrist + digits)
Supinator (supinates)
Triceps (extends forearm)
many of flexors of hand:
pronators teres + pronators quadratus (pronate hand)
flexor carpi radialis + palmaris longus (flexes forearm)
flexor digitorum superficialis and lateral half of flexor digitorum profundus (flexes wrist + digits)
flexor pollicis longus (flexes thumb)
1st + 2nd lumbricals (flexes MCP joints and extends IP joints)
motor innervation of median nerve
flexor carpi ulnaris m. (flex + adduct wrist
flexor digitorum profundus m. (flex wrist + fingers)
hypothenar m. (controls hand + 5th digit-pinky)
3rd+4th lumbricals (flexes at MCP and extends at interphalangeal joints)
interosseous m. (abducts + adducts digits)
adductor pollicis (adducts thumb)
motor innervation of ulnar nerve
holds scapula to thorax
serratus anterior m.
originates on ribs 1-8, inserts on medial border of scapula
external rotation of humerus
infraspinatous m. (posterior scapula)
abduct arm
supraspinatous m.
flexion
adduction
medial rotation of humerus
pectoralis major m.
internal rotation of arm
subscapularis m. (fills subscapular fossa, anterior scapula)
inserts in lesser tubercle of humerus
extension adduction transverse extension flexion from an extended position internal rotation
latissimus dorsi m.
medial rotation
adduction of arm
teres major m. (originates on dorsal surface of inferior angle of scapula, inserts on medial lip of intertubercle sulcus of humerus)
major flexors of arm + forearm
biceps m. + coracobrachialis m. + brachialis m.
major flexors of arm + forearm
abduct (esp frontal plane)
deltoid m.
lateral rotation of humerus
teres minor m.
extend forearm
extensors + tricep m.
pronate arm
pronators + thenar m.
flex
adduct hand
flexor carpi ulnaris m.
interosseus m.
hypothenar m.
injury to C5-C6 nerve roots or superior trunk
Erb-Duchenne Palsy (Waiter’s tip syndrome)
neck or shoulder traumatized
dystocia during delivery (large for GA)
pulling on shoulders during cephalic delivery
newborn with clavicle fracture (may not be due to a dystocia)
partial or complete paralysis of UE
bruising, stretching (usually reversible) or tearing of nerves
Erb-Duchenne Palsy (Waiter’s tip syndrome)
most common nerves affected + symptoms in Erb-Duchenne Palsy (Waiter’s tip syndrome)
loss of sensation of UE
no abduction = adducted: suprascapular n - supraspinatous m., axillary n. - deltoid m.
no lateral rotation = medial rotated: suprascapular n. - infraspinatous m.
no flexion + supination = extended + forearm pronated: musculocutaneous n. - biceps m.
injury to C8-T1 roots or inferior trunk
Klumpke palsy
cervical rib compressing inferior trunk
cervical rib compressing inferior trunk + subclavian artery →thoracic outlet syndrome
hypertrophy of anterior scalene m. → thoracic outlet syndrome
Klumpe palsy
nerves injured + symptoms of Klumpke palsy
atrophy of:
thenar eminence
hypothenar eminence: ulnar n.
interosseous muscle: ulnar n.
sensory deficits on medial side of forearm + side of hand
no radial pulse with moving head toward ipsilateral side (thoracic outlet syndrome)
sensory innervation of:
posterior arm
dorsal side of hand
radial nerve
wrist drop
difficulty straightening fingers
numbness on back of hand + posterior arm
weak brachioradialis reflex
radial nerve injury:
“saturday night palsy”
radial nerve compression or fracture of SHAFT of humerus
wrist drop
radial nerve injury
HAND ONLY:
sensory innervation of 5+ one-half of 4th digit
medial side of palm and dorsal hand
ulnar nerve
loss of flexion of wrist + digits
PROXIMAL injury to ulnar nerve (flexor carpi ulnaris + flexor digitorum profundus)
MCP joint hyperextension and IP joint flexion at 4th + 5th digitis
loss of abduction + adduction of digits
hypothenar wasting
DISTAL injury to ulnar nerve:
“ulnar claw” (lose 3rd + 4th lumbricals)
no abduction/adduction (interosseous)
sensory innervation of:
lateral palm + first 3 ½ digits
median nerve
loss of thumb abduction
median nerve injury AT THE ELBOW (no thenar m.)
“ape hand”
loss of flexion of 2nd + 3rd digits (index + middle)
median nerve injury AT OR ABOVE ELBOW:
“hand of benediction”
intermittent numbness of first 3 1/2 digits (thumb to 1/2 of ring finger)
at night or when typing (compression)
severe: atrophy of thenar m., weakness of palmar adduction/abduction
median nerve injury:
carpal tunnel syndrome
sensory innervation of:
lateral side of forearm
musculocutaneous nerve
sensory innervation of:
lateral shoulder
axillary nerve
loss of elbow flexion + supination of forearm
musculocutaneous nerve injury
loss of abduction of shoulder
weak flexion, extension, rotation of shoulder
loss of sensation to lateral shoulder
axillary nerve injury:
anterior dislocation of shoulder OR fracture of surgical NECK of humerus
artery that runs with axillary nerve
posterior circumflex artery
winged scapula
long thoracic nerve injury:
blow to neck or shoulder OR after radial mastectomy
structures in anterior triangle of neck
posterior digastric m.
sternothyroid m.
sternohyoid m. (lateral to sternothyroid)
superior omohyoid m. (lateral to sternohyoid)
structures in posterior triangle of neck
brachial plexus
subclavian vein (mid-clavicle)
external jugular vein
inferior omohyoid m.
unable to wipe bottom
thoracodorsal nerve injury
loss of forearm pronation
median nerve injury
weak external rotation of arm
suprascapular nerve injury (infraspinatous m.) + axillary nerve (deltoid m.)
supracondylar humerus fracture
median nerve
artery travels with radial nerve
deep brachial artery
nerve travels with anterior interosseous artery
anterior interosseous nerve
nerve travels with posterior interosseous artery
deep branch of radial nerve
nerve travels with suprascapular artery
suprascapular nerve
nerve travels with thoracodorsal artery
thoracodorsal nerve
nerve travels with dorsal scapular artery
dorsal scapular nerve
nerve travels with lateral thoracic artery
long thoracic nerve
nerve travels with ulnar artery
ulnar nerve
nerve travels with brachial artery
medial nerve
