BRACHIALPLEXUS
BRACHIAL PLEXUS
The parts of the brachial plexus, from medial to lateral:
• ROOTS• TRUNKS• DIVISIONS• CORDS• BRANCHES
The parts of the brachial plexus(from medial to lateral):
5 ROOTS Read3 TRUNKS The6 DIVISIONS Details3 CORDS Carefully,5 BRANCHES Bob
BRACHIAL PLEXUS 5 ROOTS
The roots of the brachial plexus are the anterior rami of C5 to T1
Therootsenterthe
posterio
rtriangleof the
neck bypassing
betweenthe
anteriorscalene
andmiddlescalenemusclesand lie
superior
andposterior to thesubclavi
anartery.
BRACHIAL PLEXUS 5 ROOTS 3 TRUNKS
The roots unite to form the trunks:
• SUPERIOR TRUNK: C5+C6
• MIDDLE TRUNK:
ONLY C7
• INFERIOR TRUNK:C8+T1
BRACHIAL PLEXUS
5 ROOTS 3 TRUNKS 6 DIVISIONS
Each of the 3 trunks of the brachial plexus divides into 2 divisions:
• anterior division
• posterior division
The trunks pass troughthe posterior triangle of the neck. The trunks pass laterally over Ist rib,and enter the axilla.
BRACHIAL PLEXUS
5 ROOTS 3 TRUNKS 6 DIVISIONS
The trunks split into:
• 3 anterior divisions
• 3 posterior divisions
The 3 cords originate from the 6 divisions
BRACHIAL PLEXUS
5 ROOTS 3 TRUNKS 6 DIVISIONS3 CORDS
THE CORDS:
• LATERAL• POSTERIOR• MEDIAL
are related to the second part of the axillary artery
BRACHIAL PLEXUS
5 ROOTS 3 TRUNKSè 6 DIVISIONSè 3 CORDS
The posterior cord occurs posterior to the second part of theaxillary artery.
The posterior cord originates as the union of all three posteriordivisions.
It contains contribu[ons from all roots of the brachial plexus (C5 to T1)
BRACHIAL PLEXUS
5 ROOTS 3 TRUNKSè 6 DIVISIONSè 3 CORDS
The lateral cord results from the union of the anterior divisions ofthe superior and middle trunks.
The lateral cord is placed lateral to the second part of the axillary artery.
BRACHIAL PLEXUS
5 ROOTS 3 TRUNKSè 6 DIVISIONSè 3 CORDS
The medial cord is the con[nua[on of the anterior division of the inferior trunk—it contains contribu[ons from C8 and T1.
The medial cord contains contribu[ons fromC8 and T1.
The medial cord is medial to the second part of theaxillary artery.
BRACHIAL PLEXUS SCHEMA OF THE BRACHIAL PLEXUS
BRACHIAL PLEXUS THE MUSCULOCUTANEOUS NERVE C5-C7
THE MUSCULOCUTANEOUS NERVE:
COURSE:• exits axilla by piercing corarobrachialis• descends between biceps brachii and brachialis (supply both)• exits laterally in forearm as lateral cutaneous nerve of forearm
MOTOR INNERVATION:• anterior flexor compartment of arm:
coracobrachialis, biceps brachii and brachialis muscles
SENSORY:• skin of the lateral aspect of the forearm
BRACHIAL PLEXUS THE MUSCULOCUTANEOUS NERVE C5-C7
THE MUSCULOCUTANEOUS NERVE:
MOTOR INNERVATION:• anterior flexor compartment of arm:
coracobrachialis, biceps brachii and brachialis muscles
INJURY:• can not flex the elbow
BRACHIAL PLEXUS THE AXILLARY NERVE C5-C6
THE AXILLARY NERVE:
COURSE:• exits axilla posteriorly• runs posterior to the SURGICAL NECK
INNERVATION:• glenohumeral (shoulder) joint• teres minor• deltoid muscle
SKIN:• skin of the superolateral arm
BRACHIAL PLEXUS THE AXILLARY NERVE C5-C6
THE AXILLARY NERVE
MUSCLE INNERVATION:• teres minor• deltoid muscle
INJURY:
• loss of abduc[on from 15-900
BRACHIAL PLEXUS SCHEMA OF THE BRACHIAL PLEXUS
BRACHIAL PLEXUS THE MEDIAN NERVE C6-T1
THE MEDIAN NERVE:
COURSE:• lateral to axillary artery• anterior to the elbow
THE MEDIAN NERVE: NO BRANCHES IN THE ARMOR AXILLA!
COURSE:• supplies and passes between two heads of the pronator teres
muscle• the nerve is closed to the surface of the wrist
BRACHIAL PLEXUS
THE MEDIAN NERVE:
INNERVATION
FOREARM:flexors of the wrist:
• pronator teres,• flexor carpi radialis,• palmaris longus,• flexor digitorum superficialis
THE MEDIAN NERVE C6-T1
Innervates most of the muscles in theanterior compartment of the forearm
(except for: the flexor carpi ulnarismuscle and the medial half of the flexordigitorum profundus muscle, which are
innervated by the ulnar nerve).
BRACHIAL PLEXUS THE MEDIAN NERVE C6-T1
THE MEDIAN NERVE:
THE BRANCHES (in the forearm):• Anterior interosseous nerve (major branch in the forearm)• Ar[cular branches• Muscular branches• Palmar cutaneous branch of the median nerve
BRACHIAL PLEXUS THE MEDIAN NERVE C6-T1
THE MEDIAN NERVE
INNERVATION:HAND:• two lateral lumbricals: 1st and 2nd• thenar eminence via the reccurent branch: opponens pollicis,
abductor pollicis brevis
SENSORY• lateral three and one-half fingers of palmar surface• superior dorsal apects (three and one-half finger[ps)
BRACHIAL PLEXUS THE MEDIAN NERVE C6-T1
THE MEDIAN NERVE
INJURY• carpal tunnel syndrome – reduced the size of the carpal tunnel• lunate disloca[on• supra-epicondylar fracture of humerus
BRACHIAL PLEXUS THE MEDIAN NERVE C6-T1THE MEDIAN NERVE
The carpal tunnel syndrome causes:
MEDIAN TRAP
Myxedema (hypothyroidism)EdemaDiabetesIdiopathicAcromegalyNeoplasmTrauma Rheumatoid arthri[s Amyloidosis Pregnancy
BRACHIAL PLEXUS THE MEDIAN NERVE C6-T1
THE MEDIAN NERVE
The carpal tunnel syndrome:• any pathology that expands the contents of the tunnel will
compress the enclosed median nerve• tendoni[s of the flexor re[naculum from overuse – median nerve
entrapment
Findings:• numbness• [ngling or sensory loss• atrophy of thenar eminence
BRACHIAL PLEXUS THE MEDIAN NERVE C6-T1
THE MEDIAN NERVE
INJURY OF THE MEDIAN NERVEThe median nerve controls the 1st & 2nd lumbricals, three thenar muscles.
Addi[onally there may be thenar atrophy.
The hand of benedic[on is only apparent if the pa[ent is asked to makea fist - pa[ent will be able to flex the lihle and ring fingers.
POPE'S HAND (HAND OF BENEDICTION)
BRACHIAL PLEXUS SCHEMA OF THE BRACHIAL PLEXUS
BRACHIAL PLEXUS THE RADIAL NERVE C5-T1
THE RADIAL NERVE:
COURSE:• posterior to brachial artery• runs with the profunda brachii artery• radial groove in humerus• con[nues inferiorly in the anterior compartment of the arm• between the brachialis and the brachioradialis• to the level of the anterior part of the lateral epicondyle of
humerus
BRACHIAL PLEXUS THE RADIAL NERVE C5-T1
THE RADIAL NERVE:
MOTOR INNERVATIONS:• triceps• brachioradialis
MOTOR INNERVATIONS:• extensors of the wrist - posterior compartment of forearm: extensorcarpi radialis longus, extensor carpi radialis brevis, extensor digitorum,extensor digi; minimi, extensor carpi ulnaris, supinator, extensor indicis, abductor policis longus, extensor policis longus, extensor policis brevis
BRACHIAL PLEXUS THE RADIAL NERVE C5-T1
THE RADIAL NERVE - INNERVATION OF THE SKIN:• posterior arm and forearm• on dorsal hand - below the finger[ps of the medial three and one-half fingers
THE RADIAL NERVE INJURY maybe due to:• fracture of the body of humerus (radial groove)• saturday night palsy (compression of the nerve)
THE RADIAL NERVEPa[ent is not able to extendINJURY
the wrist and fingers in the MPRESULT INjointsTHE WRIST DROP
BRACHIAL PLEXUS THE RADIAL NERVE C5-T1
DORSAL BRANCH OF ULNAR NERVESkin of medial aspect of dorsum of hand and proximal por[ons of lihle and medial half of ring finger
SUPERFICIAL BRANCH OF ULNAR NERVEPalmaris brevis & sensa[on to skin of the palmar and distal dorsal aspects of digit 5 and of the medial (ulnar) side of digit 4 and proximal por[on of palm
DEEP BRANCH OF ULNAR NERVEHypothenar muscles, lumbricals of digits 4 and 5, all interossei, adductor pollicis, and deep head of flexor pollicis brevis
BRACHIAL PLEXUS SCHEMA OF THE BRACHIAL PLEXUS
BRACHIAL PLEXUS THE ULNAR NERVE C7, C8-T1
THE ULNAR NERVE:
COURSE:• passes on the medial side of the brachial artery• descends between the medial intermuscular septum of the arm and
the medial head of triceps
THE ULNAR NERVE – NO BRANCHES IN THE ARM !
THE MEDIAN NERVE – NO BRANCHES IN THE ARM !
BRACHIAL PLEXUS THE ULNAR NERVE C7, C8-T1
THE ULNAR NERVE:
COURSE:• passes posterior to the medial epicondyle and to the medial
olecranon to enter the forearm
• passes superficial to the flexor re[naculum(the median nerve under the flexor re;naculum)
• enters the hand by passing through a groove between the pisiform and the hook of the hamate – the ulnar canal (Guyon’s canal)
BRACHIAL PLEXUS THE ULNAR NERVE C7, C8-T1
THE ULNAR NERVE:
INNERVATION OF FOREARM:• innervates medial flexors of the wrist: flexor carpi ulnaris and
medial part of the flexor digitorum profundus
INNERVATION OF HAND:• hypothenar eminence: abductor digi; minimi, flexor digi; minimi
brevis, opponens digi;• medial lumbrical muscles: 3rd and 4th lumbricals• all interosseous muscles of the hand: 1st – 4th dorsal interossei,
1st-3rd palmar interossei
THE ULNAR NERVE:SKIN INNERVATION:• dorsal and palmar apsect of the hand for medial 1 ½ fingers• medial forearm
BRACHIAL PLEXUS THE ULNAR NERVE C7, C8-T1
THE ULNAR NERVE INJURY may be due to:• medial epicondyle fracture• fracture of the hook of hamate
THE ULNAR NERVE INJURYRESULTS IN:• inability to abduct or adduct fingers• hypothenar atrophy• Ulnar Claw Hand:
• loss of medial lumbricals• pa[ent tries to open hand and cannot extend 4th and 5th digits
BRACHIAL PLEXUS
VSINJURY OF THE MEDIAN NERVE
POPE'S HAND(HAND OF BENEDICTION)
the pa[ent isasked to make afist: pa[ent willbe able to flex
the lihle andring fingers.
INJURY OF THE ULNAR NERVE
ULNAR CLAW HAND
pa[ent tries to open hand and cannot extend 4th and 5th digits
DUPUYTREN CONTRACTURE OF PALMAR FASCIA
• Its cause is unknown• The fibrous degenera[on of the longitudinal bands of the palmar
aponeurosis on the medial side of the hand pulls the 4th and 5th fingers into par[al flexion at the metacarpophalangeal and proximal interphalangeal joints
• The contracture is frequently bilateral and is seen in some men > 50 years of age
BRACHIAL PLEXUS
SENSORY INNERVATION OF THE HAND