Roots (ventral rami) C5-T1 Trunks superior, middle, inferior Divisions anterior, posterior Cords Lateral, posterior, anterior Branches ()

PNS upper 1 Trunk Root Division

Cord

PNS upper 2 Brachial plexus: TRUNKS and DIVISIONS Trunks Superior trunk: union of C5-C6 roots Middle trunk: continuation of C7 root Inferior trunk: union of C8-T1 roots Divisions Each trunk divides into 2 Divisions when passing posterior to clavicle (cervicoaxillary canal) Anterior division: anterior (flexor) compartments Posterior division: posterior (extensor) compartments PNS upper 3 Suprascapular

Dorsal scapular Subclavius

Long thoracic PNS upper 4 Brachial plexus: branches

Root level long thoracic n (serratus anterior) dorsal scapular n (rhomboid, levator scapulae) Trunk level N to subclavius (subclavius) Division level suprascapular n (supraspinatus, infraspinatus)

PNS upper 5 Serratus anterior Rib l-8 → med. border of scapula : C5-7; long thoracic n. Action: keep scapula against thoracic wall on pushing PNS upper 6 Scapular winging: paralysis of serratus anterior muscle

Long thoracic n.

PNS upper 7 Brachial plexus: terminal mixed n ulnar n () musculocutaneous n (lat cord) axillary n (post cord) radial n. (post cord) median n (lat/med cord)

PNS upper 8 Dermatome of

C3-4: neck, shoulder C5: (sup/lat) C6: (lat), C7: 2-4 fingers C8: 4-5 fingers T1: forearm (middle) T2: arm, axillary

PNS upper 9 Dermatome: Embryology view Extremities developed from limb buds in the body wall

PNS upper 10 Peripheral nerve territory of upper limbs

/Finger Ulnar Radial Median

PNS upper 11 Dermatome and Sensory nerve territory C8

Medial antebrachial cutaneous nerve

C8 dermatome

Ulnar territory

PNS upper 12 Median nerve Mainly C6-T1; medial to Sensory fibers: cutaneous and Brachial artery articular branches Motor fibers Flexors of to thenar muscles

PNS upper 13 Median N: motor Abduction/opposition of thumb abductor policis brevis opponents policis Pronation of forearm Pronator teres Flexion of hand Flexor muscles of wrist and fingers

PNS upper 14 Motor innervation and C6 Myotome

C8 Median nerve

Flexor carpi C6 myotome radialis

Median-innervated muscles

C8 myotome Abductor policis brevis PNS upper 15 Flexor retinaculum /

PNS upper 16 Median nerve lesion at wrist PNS upper 17

Atrophy of thenar muscles: unable to abduct Weakness of thumb opposition only flexion and extension

PNS upper 18 Ulnar nerve Mainly C7-T1 Sensory fibers: cutaneous and articular branches Motor fibers Flexors of wrist and fingers Intrinsic hand muscles

PNS upper 19 Ulnar nerve: motor functions Flexion of wrist (ulnar side) Flexor carpi ulanris Flexion of 4th, 5th fingers Flexor digitorium profundus (FPF) Abduction of 1st dorsal interosseous

PNS upper 20 Ulnar nerve lesion

PNS upper 21 Ulanr nerve palsy Lesion at the : “clawhand” Atrophy of hypothenar muscle Weakness: flexor of 4th, 5th fingers Reduced sensation: 4th, 5th fingers

PNS upper 22 from post. Cord vs. lesion for muscles of posterior compartment Elbow extension Triceps brachii Wrist extension Finger extension PNS upper 23 Radial nerve

PNS upper 24 Radial nerve palsy Saturday night palsy, Honeymoon palsy

PNS upper 25 Nerves in upper limb

Brachial plexus  Median nerve Ulnar nerve Radial nerve Axillary nerve Functional innervation motor and sensory deficits on nerve injury

PNS upper 27