Anatomy of brachial plexus

Anatomy of brachial plexus explained in detail along with nerve supply of all the muscles of upper limb and various paralysis caused by brachial plexus injury

1. SURGICAL ANATOMY OF BRACHIAL PLEXUS PRESENTER-DR.PRINCE LATHIYA (2 nd YEAR SURGERY PGT) MODERATOR-DR.R.C.SHYAM (ASST. PROFFESSOR)

2. BRACHIAL PLEXUS

3. Formed by the ventral rami of the lower cervical and upper thoracic nerve roots it includes – from above the fifth cervical vertebra to underneath the first thoracic vertebra(C5-T1).

4. FORMATION OF THE BRACHIAL PLEXUS Roots The ventral rami of spinal nerves C5 to T1 are referred to as the roots of the plexus. Trunks –The ventral rami of C5 & C6 unite to form the Upper Trunk. –The ventral ramus of C7 continues as the Middle Trunk. –The ventral rami of C8 & T1 unite to form the Lower Trunk.

5. •Divisions Trunk splits into an anterior division and a posterior division. –The anterior divisions usually supply flexor muscles –The posterior divisions usually supply extensor muscles. Cords –The anterior divisions of the upper and middle trunks unite to form the lateral cord. –The anterior division of the lower trunk forms the medial cord. –All 3 posterior divisions from each of the 3 cords unite to form the posterior cord. –The cords are named according to their position relative to the axillary artery

6. III. BRANCHES : Nerves that are branches from portions of the brachial plexus usually contain only 1 type of axon. From the Roots Dorsal Scapular nerve Derived from C5 root Motor nerve to the Rhomboideus major and minor muscles Long Thoracic nerve Derived from C 5,6,7 Innervates the serratus anterior muscle

7. From the Upper Trunk Nerve to subclavius muscle Suprascapular nerve Innervates supra and infraspinatus muscles From the Lateral Cord Lateral Pectoral nerve Innervates the clavicular head of the pectoralis major muscle From the Medial Cord Medial Pectoral nerve Innervates the sternocostal head of the pectoralis major muscle Innervates the pectoralis minor muscle

8. FROM NERVE ROOTS MUSCLE CUTANEOUS ROOTS dorsal scapular nerve C5 rhomboid muscles and levator scapulae ROOTS long thoracic nerve C5,C6,C7 serratus anterior UPPER TRUNK nerve to the subclavius C5,C6 subclavius muscle UPPER TRUNK suprascapular nerve C5,C6 supraspinatus and infraspinatus

9. Lateral Cord lateral pectoral nerve C5, C6, C7 pectoralis major (by communicating with the medial pectoral nerve ) Lateral Cord musculocutaneous nerv C5, C6, C7 coracobrachialis , brachialis and biceps brachii becomes the lateral cutaneous nerve of the forearm Lateral Cord lateral root of the median nerve C5, C6, C7 fibres to the median nerve

10. POSTERIOR CORD Posterior Cord upper subscapular nerve C5, C6 subscapularis (upper part) Posterior Cord thoracodorsal nerve (middle subscapular nerve) C6,C7,C8 latissimus dorsi Posterior Cord lower subscapular nerve C5, C6 subscapularis (lower part ) and teres major

11. Posterior Cord Axillary Nerve C5, C6 Anterior Branch: Deltoid And A Small Area Of Overlying Skin Posterior Branch: Teres Minor And Deltoid Muscles Posterior Cord Radial Nerve C5, C6, C7, C8, T1 Triceps Brachii , Supinator , Anconeus , The Extensor Muscles Of The Forearm , And Brachioradialis

12. MEDIAL CORD Medial cord Medial pectoral nerve C8,T1 Pectoralis major and pectoralis minor Medial cord Medial root of the median nerve C8,T1 Fibres to the median nerve Portions of hand not served by ulnar or radial Medial cord Medial cutaneous nerve of the arm C8,T1 Front and medial skin of the arm

13. Medial Cord Medial Cutaneous Nerve Of The Forearm C8, T1 Medial Skin Of The Forearm Medial Cord Ulnar Nerve C8, T1 Flexor Carpi Ulnaris , The Medial 2 Bellies Of Flexor Digitorum Profundus , The Intrinsic Hand Muscles Except The Thenar Muscles And The Two Most Lateral Lumbricals The skin of the medial side of the hand medial one and a half fingers on the palmar side and medial two and a half fingers on the dorsal side

14. BRACHIAL PLEXUS INJURIES

15. Klumpke’s palsy Named after augusta déjerine-klumpke , klumpke's paralysis is a variety of partial palsy of the lower roots of the brachial plexus. Results from a brachial plexus injury in which C8 and T1 nerves are injured . Affects, the intrinsic muscles of the hand and the flexors of the wrist and fingers. The classic presentation of klumpke's palsy is the “claw hand” where the forearm is supinated and the wrist and fingers are hyperextended with flexion at interphalangeal and metatarso phalangeal joints.

16. Erb’s palsy Erb's palsy ( Erb-Duchenne Palsy ) is a paralysis of the arm caused by injury to the upper trunk C5-C6. signs of Erb's Palsy include loss of sensation in the arm and paralysis and atrophy of the deltoid, biceps, and brachialis muscles. the arm hangs by the side and is rotated medially; the forearm is extended and pronated . commonly called "waiter's tip hand."

17. UPPER LIMB

18. MUSCLES OF PECTORAL REGION PECTORALIS MAJOR PECTORALIS MINOR SUBCLAVIUS

19. MUSCLES OF SHOULDER GIRDLE Deltoid Supra Spinatus Infra Spinatus Subscapularis Teres Minor. Teres major

20. MUSCLES OF ARM FLEXOR COMPARTMENT : BICEPS BRACHII CORACO BRACHIALIS BRACHIALIS EXTENSOR COMPARTMENT TRICEPS

21. MUSCLES OF FOREARM Anterior Compartment : common flx.origin SUPERFICIAL 1.Pronator Teres 2.Flx.Carpi Radialis 3.Palmaris Longus 4.Flx.Carpi Ulnaris 5.Flx.Digitorum Superficialis DEEP 1.Flx.Digitorum Profundus 2.Flx.Pollicis Longus 3.Pronator Quadratus

22. POSTERIOR COMPARTMENT SUPERFICIAL: 1. Anconeus 2.Brachioradialis 3.Ext.Carpi Radialis Longus 4.Ext.Carpi Radialis Brevis 5.Ext.Digitorum 6.Ext.Digiti Minimi 7.Ext.Carpi Ulnaris DEEP: 1.Abductor Pollicis Longus 2.Ext.Pollicis Brevis 3.Ext.Pollicis Brevis 4.Ext.Indicis 5.Supinator

23. INTRINSIC MUSCLES OF THE HAND Thenar muscles Abductor pollicis brevis Flx.pollicis brevis Opponens pollicis Adductor pollicis Hypothenar muscles- Palmaris brevis Abductor digiti minimi Flx.digiti minimi Opponens digiti minimi Lumbricals -4 Palmar interossei-4 Dorsal interosei-4

24. Flexor retinaculum On the ulnar side, the flexor retinaculum attaches to the  pisiform bone  and the  hook of the hamate bone . On the radial side, it attaches to the tubercle of the  scaphoid bone , and to the medial part of the palmar surface and the ridge of the  trapezium bone .

25. SPACES OF HANDS The spaces of hand are of practical significance because they may become infected and in consequence become distended with pus. The important spaces are: The superficial pulp spaces of the finger. The synovial tendon sheaths of the 2 nd, 3 rd and 4 th finger. The ulnar bursa The radial bursa The midpalmar space The thenar space

26. SUPERFICIAL PULP SPACE Subcutaneous space between distal phalanx and skin of terminal digit. Proximally – closed anteriorly by fusion of fibrous flexor sheath to skin of digit at distal crease Posteriorly fusion of deep fascia to periosteum of terminal phalanx

27. Synovial tendon sheath The common synovial sheath for the flexor tendons is a synovial sheath in the carpal tunnel. It contains tendons of the flexor digitorum superficialis and the flexor digitorum profundus , but not the flexor pollicis longus .

28. Radial Bursa The synovial sheath of the tendon of flexor pollicis longus (radial bursa). This sheath is usually separate but may be communicate with the common sheath behind the retinaculum .

29. Ulnar bursa Common flexor synovial sheath ( ulnar bursa). The long flexor tendons of the fingers (flexor digitorum superficialis and profundus ), are enclosed in a common synovial sheath while passing deep to the flexor retinaculum .

30. Thenar space BOUNDARIES Anterior - Palmar aponeurosis / superficial palmar arch, flexor tendon of index finger covered with synovial sheath / tendon of FPL Posterior – fascia covering adductor pollicis Lateral - Lateral palmar septum Medial - MidPalmar septum Proximal – distal margin of flexor retinaculum Distal - 1 st web space thru lumbrical canal

31. Mid palmer space Anterior – Palmar aponeurosis / superficial palmar arch, flexor tendons of medial 3 digits covered in ulnar bursa and medial 3 lumbricals Posterior - Fascia covering 3 rd & 4 th interossei and metacarpal bones Medial – Medial Palmar septum Lateral - Midpalmar septum Proximal – distal margin of flexor retinaculum Distal - medial 2 web spaces thru lumbrical canals

32. ARTERIAL SUPPLY

33. AXILLARY ARTERY Origination: Begins at the lateral border of 1 st rib as a continuation of subclavian artery. Termination: Ends at the lower border of teres major muscle by continuing as brachial artery.

34. PARTS OF AXILLARY ARTERY Divides it into 3 parts. First part: Proximal to pectoralis minor (from lateral border of 1 st rib to upper border of pectoralis minor). Second part: Deep (behind) to pectoralis minor. Third part: Distal to pectoralis minor (from lower border of pectoralis minor to lower border of teres major)

35. BRANCHES OF AXILLARY ARTERY Branches from 1 st part: Superior (highest) thoracic artery Branches from 2 nd part : Thoraco-acromial artery Lateral Thoracic artery Branches from 3 rd part : Subscapular artery Anterior circumflex humeral artery Posterior circumflex humeral artery

36. BRACHIAL ARTERY Origination: continuation of Axillary artery. Termination: Opposite the neck of the radius in the cubital fossa by dividing into Radial and Ulnar arteries.

37. Runs inferiorly and slightly laterally on the medial side of biceps brachii muscle to the cubital fossa , where it ends opposite the neck of the radius. At first it lies medial to the humerus and then lateral to it. It lies anterior to the triceps brachii and brachialis muscle and is overlaped by the biceps brachii and choracobrachialis .

38. BRANCHES OF BRACHIAL ARTERY Muscular branches Nutrient artery to humerus Profunda Brachii artery (accompanies the radial nerve) Superior ulnar collateral branch (accompanies the ulnar nerve) Inferior ulnar collateral (or supratrochlear ) branch Terminal branches (ends by) ( i ) Radial artery (ii) Ulnar artery

39. RADIAL ARTERY Smaller terminal branch of Brachial artery. Origination: Begins in the cubital fossa & passes below Brachioradialis muscle. Termination: Continues in hand as deep palmar arch

40. RELATION lies deep to brachioradialis but in lower part it becomes superficial between brachioradialis tendon and flexor carpi radialis tendon Its bed is formed by biceps, supinator , pronator , F.D.S, F.P.L, pronator quadratus & styloid process of radius. At wrist it winds backward and passes anteriorly into the palm between two heads of 1 st dorsal interossei muscle. Then it joins deep branch of ulnar artery to form Deep Palmar Arch.

41. ULNAR ARTERY Larger terminal branch of Brachial artery. Origination: Begins in the cubital fossa & descends through anterior compartment of forearm. Termination: It ends by forming Superficial Palmar Arch with Superficial Palmar branch of Radial artery.

42. RELATION It goes down & medially deep to P.T, F.C.R, P.L, F.C.U, F.D.S. Its bed is formed by brachialis (in upper part only) & F.D.P. (in lower part). In lower part it becomes superficial by coming in between tendons of F.C.U. and F.D.S.

43. SUPERFICIAL PALMER ARCH Formation: From medial side: Direct continuation of Ulnar artery. From lateral side: The Arch is completed by superficial palmar branch of the radial artery.

44. DEEP PALMER BRANCH Formation: From lateral side: By direct continuation of Radial artery. From medial side: The Arch on medial side is completed by deep branch of the ulnar artery.

45. VEINS OF UPPERLIMB Divided into superficial and deep drainage. Deep drainage follows the arteries previously mentioned and are named similarly (i.e., brachial artery—brachial vein). The superficial drainage is the cephalic and basilic veins which drain subcutaneous tissue and eventually drain.

46. NERVE SUPPLY

47. AXILLARY NERVE Arise from posterior cord of brachial plexus Lies posterior to the axillary artery and anterior to the subscapularis muscles. Divide into anterior branch (upper branch) and posterior branch (lower branch). Anterior branch innervate anterior border of deltoid muscles (anterior and lateral fiber) Posterior border supply teres minor and posterior part of the deltoid (posterior fiber). Then it will branch of to formed superior lateral cutaneous nerve of arm (superior lateral brachial cutaneous ).

48. Muscular innervations - anterior branch – anterior and lateral fiber of deltoid muscles - posterior branch – teres minor and posterior fiber of deltoid Cutaneous innervation superior lateral brachial cutaneous nerve - carry information from the shoulder joint - skin covering inferior region of deltoid muscles.

49. Musculocutaneous Nerve Arise from lateral cord of brachial plexus Opposite to the lower border of pectoralis minor Arise from root C5, C6 and C7. Penetrate coracobrachialis and pass obliquely between biceps brachii and the brachialis to the lateral side of the arm. Continue in the forearm as the lateral cutaneous nerve of forearm

50. INNERVATION Muscular innervation Supply coracobrachialis , biceps brachii and brachialis Cutaneous innervation . Lateral antebrachial cutaneous nerve divide into anterior and posterior branch. Anterior branch – skin of anterolateral surface of forearm as far as ball of the thumb Posterior branch – skin of posterolateral surface of forearm.

51. Radial Nerve Arise from posterior cord of brachial plexus Arise from root C5, C6, C7, C8 & T1. Travels first in the posterior compartment of the arm, and later in the anterior compartment of the arm, and continues in the posterior compartment of the forearm. The radial nerve enter the arm behind the axillary artery and then travel posteriorly on the medial side of the arm.

52. Then radial nerve will innervate triceps brachii . Radial nerve then enter the radial groove. Radial nerve emerge from radial groove and enter the anterior compartment of the arm. It continue the journey between brachialis and brachioradialis . When the radial nerve reaches the distal part of the humerus , it passes anterior to the lateral epicondyle and continue to the forearm.

53. In the forearm it divides into superficial and deep motor branches. Superficial branches – 1. Posterior cutaneous nerve of arm 2. Inferior lateral cutaneous nerve of arm 3. Posterior cutaneous nerve of forearm 4. Superficial branch Deep branches – 1.Triceps brachii 2.Anconeus 3.Brachioradialis 4.Supinator

54. ULNAR NERVE Arise from medial cord of brachial plexus Root C8 and T1 (mostly C7) Descend on the posteromedial of the humerus . Then it goes posterior to the medial epicondyle . Enter anterior compartment muscles of forearm and supplies flexor carpi ulnaris and medial half flexor digitorum profundus . Then ulna nerve enter palm of the hand and branch off to the superficial branch and deep branch .

55. Deep branch innervate hypothenar muscles, intermediate hand muscles and thenar hand muscles (adductor pollicis , flexor pollicis brevis (rare)) Superficial branches of Ulnar nerve will innervate palmaris brevis and skin anterior and posterior of the hand (medial aspect of the hand/ one an half digits)

56. MEDIAN NERVE Arise from lateral root of lateral cord (C5,6,7) and medial root and medial cord (C8,T1) of brachial plexus. Passes down the midline of the arm in close association with the brachial artery. Passes in front of elbow joint ( cubital fossa ) then down to supply the muscles of the anterior of forearm. Then it continue into the hand through carpal tunnel where it supply intrinsic hand muscles and skin of the hand .