Muscles of the Forearm and Hand: Extensor Muscles 393

Extensor muscles of forearm and hand, deep layer

(dorsal aspect).

1 Triceps brachii muscle

2 Lateral intermuscular septum

3 Lateral epicondyle of humerus

4 Anconeus muscle

5 Extensor digitorum and extensor digiti minimi

muscles (cut)

6 Supinator muscle

7 Extensor carpi ulnaris muscle

8 Extensor retinaculum

9 Third and fourth dorsal interosseous muscles

10 Tendons of extensor digitorum muscle (cut)

11 Biceps brachii muscle

12 Brachialis muscle

13 Brachioradialis muscle

14 Extensor carpi radialis longus muscle

15 Extensor carpi radialis brevis muscle

16 Abductor pollicis longus muscle

17 Extensor pollicis longus muscle

18 Extensor pollicis brevis muscle

19 Extensor indicis muscle

20 Tendons of the extensor carpi radialis longus

and extensor carpi radialis brevis muscles

21 First dorsal interosseous muscle

Position of extensor muscles of forearm and hand

(schematic drawing).

A Extensors of thumb B Extensors of fingers and hand

1 Abductor pollicis longus muscle 5 Extensor carpi ulnaris muscle

(red) (blue)

2 Extensor pollicis brevis muscle 6 Extensor digitorum muscle

(blue) (red)

3 Extensor pollicis longus muscle 7 Extensor carpi radialis brevis

(red) muscle (blue)

4 Extensor indicis muscle 8 Extensor carpi radialis longus

(blue) muscle (blue)

394 Muscles of the Hand

Muscles of thumb and index finger (medial aspect).

The tendons of the extensor muscles of the thumb and

the insertion of the flexor tendons of the index finger

are displayed.

Muscles of right hand (palmar aspect). The tendons of the flexor muscles

and parts of the thumb muscles have been removed. The carpal tunnel has

been opened.

1 Tendons of extensor pollicis brevis

and abductor pollicis longus muscle

2 Extensor retinaculum

3 Tendon of extensor pollicis longus muscle

4 Tendons of extensor carpi radialis longus

and brevis muscles

5 First dorsal interosseous muscle

6 Tendon of extensor digitorum muscle for

index finger

7 Location of metacarpophalangeal joint

8 Tendon of lumbrical muscle

9 Extensor expansion of index finger

10 Tendon of flexor carpi radialis muscle

(cut)

11 Anatomical snuffbox

12 Tendon of abductor pollicis longus muscle

13 Tendon of extensor pollicis brevis muscle

14 Tendon of abductor pollicis brevis muscle

15 Extensor expansion of extensor of thumb

16 Vinculum longum

17 Tendons of flexor digitorum

superficialis muscle dividing to allow

passage of deep tendons

18 Vincula of flexor tendons

19 Tendon of flexor digitorum profundus muscle

20 Vinculum breve

21 Radial carpal eminence (cut edge of

flexor retinaculum)

22 Opponens pollicis muscle

23 Deep head of flexor pollicis brevis muscle

24 Abductor pollicis brevis muscle (cut)

25 Superficial head of flexor pollicis brevis

muscle (cut)

26 Oblique head of adductor pollicis muscle

27 Transverse head of adductor pollicis muscle

28 Tendon of flexor pollicis longus muscle (cut)

29 Lumbrical muscles (cut)

30 First dorsal interosseous muscle

31 Position of carpal tunnel

32 Tendon of flexor carpi ulnaris muscle

33 Location of pisiform bone

34 Hook of hamate bone

35 Abductor digiti minimi muscle

36 Flexor digiti minimi brevis muscle

37 Opponens digiti minimi muscle

38 Second palmar interosseous muscle

39 Third palmar interosseous muscle

40 Fourth dorsal interosseous muscle

41 Third dorsal interosseous muscle

42 Tendon of flexor digitorum

profundus muscle (cut)

43 Tendons of flexor digitorum

superficialis muscle (cut)

44 Fibrous flexor sheaths

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Muscles of the Hand

Muscles of right hand, deep layer (palmar aspect). The thenar and

hypothenar muscles have been removed to display the interosseous

muscles.

Transverse section through the right hand, showing the carpal tunnel

(canalis carpi).

Actions of interosseous muscles in abduction and

adduction of fingers (palmar aspect, schematic drawing).

Arrow: carpal tunnel.

Red = abduction (dorsal interosseous, abductor digiti minimi,

and abductor pollicis brevis muscles)

Blue = adduction (palmar interosseous muscles, adductor

pollicis muscle)

1 Pronator quadratus muscle

2 Tendon of flexor carpi radialis muscle

3 Abductor pollicis brevis muscle (divided)

4 Adductor pollicis muscle (divided)

5 Tendon of flexor pollicis longus muscle

6 Lumbrical muscles (cut)

7 Tendon of flexor carpi ulnaris muscle

8 Pisiform bone

9 Abductor digiti minimi muscle (divided)

10 Dorsal interosseous muscles

11 Palmar interosseous muscles

12 Radius

13 Ulna

14 Flexor retinaculum

15 Tendons of flexor digitorum

profundus muscle

16 Tendons of flexor digitorum

superficialis muscle

17 Capitate bone

18 Trapezium bone and trapezoid bone

19 Radial artery

20 Tendon of flexor muscles

21 First metacarpal bone

22 Median nerve

23 Thenar muscles

24 Hamate bone

25 Hypothenar muscles

26 Ulnar artery and nerve

27 Carpal tunnel (canalis carpi)

396 Arteries

Main branches of right subclavian and axillary arteries (anterior aspect). Pectoralis muscles have been reflected, clavicle and anterior

wall of thorax removed, and right lung divided. Left lung with pleura and thyroid gland have been reflected laterally to display aortic arch

and common carotid artery with their branches.

1 Pectoralis minor muscle (reflected)

2 Anterior circumflex humeral artery

3 Musculocutaneous nerve (divided)

4 Axillary artery

5 Posterior circumflex humeral artery

6 Profunda brachii artery

7 Median nerve (var.)

8 Brachial artery

9 Biceps brachii muscle

10 Thoraco-acromial artery

11 Suprascapular artery

12 Descending scapular artery

13 Brachial plexus (middle trunk)

14 Transverse cervical artery

15 Scalenus anterior muscle and phrenic nerve

16 Right internal carotid artery

17 Right external carotid artery

18 Carotid sinus

19 Superior thyroid artery

20 Right common carotid artery

21 Ascending cervical artery

22 Thyroid gland

23 Inferior thyroid artery

24 Internal thoracic artery

25 Right subclavian artery

26 Brachiocephalic trunk

27 Left brachiocephalic vein (divided)

28 Left vagus nerve

29 Superior vena cava (divided)

30 Ascending aorta

31 Median nerve (divided)

32 Phrenic nerve

33 Right lung (divided) and pulmonary pleura

34 Thoracodorsal artery

35 Subscapular artery

36 Lateral mammary branches (variant)

37 Lateral thoracic artery

38 Thyrocervical trunk

39 Superior thoracic artery

40 Superior ulnar collateral artery

41 Inferior ulnar collateral artery

42 Middle collateral artery

43 Radial collateral artery

44 Radial recurrent artery

45 Radial artery

46 Anterior and posterior interosseous

arteries

47 Princeps pollicis artery

48 Deep palmar arch

49 Common palmar digital arteries

50 Ulnar recurrent artery

51 Recurrent interosseous artery

52 Common interosseous artery

53 Ulnar artery

54 Superficial palmar arch

55 Median nerve and brachial artery

56 Biceps brachii muscle

57 Ulnar nerve

58 Flexor pollicis longus muscle

59 Palmar digital arteries

60 Anterior interosseous artery

61 Flexor carpi ulnaris muscle

62 Superficial palmar branch of radial artery

Arteries 397

Dissection of the arteries of forearm and hand.

The superficial flexor muscles have been removed, the carpal

tunnel opened, and the flexor retinaculum cut. The arteries have

been filled with colored resin.

Arteries of the upper limb (schematic drawing).

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Veins

Veins of the head, neck, and upper extremity

and their connection with the heart (antero-lateral

aspect). Anterior thoracic wall has been opened.

Superficial veins of upper limb

(schematic drawing).

1 Superficial temporal artery and vein

2 Occipital vein

3 Parotid gland

4 Great auricular nerve and

sternocleidomastoid muscle

5 External jugular vein

6 Internal jugular vein and common carotid artery

7 Deltoid muscle

8 Axillary vein

9 Right cephalic vein within the

deltopectoral groove

10 Right lung (middle lobe)

11 Serratus anterior muscle and

lateral thoracic vein

12 Cephalic vein on forearm

13 Venous network on dorsum of hand

14 Dorsal metacarpal veins

15 Facial artery and vein

16 Submandibular gland

17 Anterior jugular vein, hyoid bone,

and omohyoid muscle

18 Jugular venous arch and thyroid gland

19 Right and left brachiocephalic veins

20 Retrosternal body

(remnant of thymus gland)

21 Internal thoracic artery and vein

22 Heart with pericardium

23 Right venous angle

24 Brachial vein

25 Basilic vein

26 Median cubital vein

27 Digital veins

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Nerves 399

Main branches of radial nerve (schematic drawing).

Posterior divisions of trunks and posterior cord and its

branches are indicated in green.

Main branches of musculocutaneous, median, and

ulnar nerves (schematic drawing).

Anterior divisions of the trunks and all the components

arising from them are indicated in yellow.

1 Brachial plexus

2 Lateral cord of brachial plexus

3 Posterior cord of brachial plexus

4 Medial cord of brachial plexus

5 Axillary nerve

6 Radial nerve

7 Posterior cutaneous nerve of arm

8 Lower lateral cutaneous nerve of arm

9 Posterior cutaneous nerve of forearm

10 Superficial branch of radial nerve

11 Deep branch of radial nerve

12 Dorsal digital nerves

13 Roots of median nerve

14 Musculocutaneous nerve

15 Median nerve

16 Ulnar nerve

17 Medial cutaneous nerves of arm and forearm

18 Lateral cutaneous nerve of forearm

19 Anterior interosseous nerve

20 Palmar branch of median nerve

21 Dorsal branch of ulnar nerve

22 Deep branch of ulnar nerve

23 Common palmar digital nerves of median nerve

24 Superficial branch of ulnar nerve

400 Nerves

Cutaneous nerves of the right upper limb

(ventral aspect, schematic drawing).

Cutaneous nerves of the right upper limb

(dorsal aspect, schematic drawing).

1 Medial supraclavicular nerve

2 Intermediate supraclavicular nerve

3 Upper lateral cutaneous nerve of arm

4 Terminal branches of intercostobrachial nerves

5 Lower lateral cutaneous nerve of arm

6 Lateral cutaneous nerve of forearm

7 Terminal branch of superficial branch of radial nerve

8 Palmar digital nerve of thumb (branch of median nerve)

9 Palmar digital branches of median nerve

10 Anterior cutaneous branches of intercostal nerves

11 Lateral cutaneous branches of intercostal nerves

12 Medial cutaneous nerve of forearm

13 Palmar cutaneous branch of ulnar nerve

14 Palmar branch of median nerve

15 Palmar digital branches of ulnar nerve

16 Cutaneous branches of dorsal rami of spinal nerves

17 Dorsal branch of ulnar nerve

18 Dorsal digital nerves

19 Posterior supraclavicular nerve

20 Posterior cutaneous nerve of arm

21 Posterior cutaneous nerve of forearm

from radial nerve 22 Superficial branch

23 Dorsal digital branches

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Surface Anatomy of the Upper Limb: Posterior and Lateral Aspects 401

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1 Olecranon

2 Extensor muscles of forearm

3 Accessory cephalic vein

4 Tendons of extensor digitorum

muscle

5 Dorsal venous network

of hand

6 Deltoid muscle

7 Triceps brachii muscle

8 Lateral epicondyle of humerus

9 Brachioradialis muscle

10 Cephalic vein

11 Tendon of abductor pollicis

longus muscle

12 Tendon of extensor indicis

muscle

13 Sternocleidomastoid muscle

14 Clavicle

15 Lateral head of triceps

brachii muscle

16 Medial head of triceps

brachii muscle

17 Tendon of triceps

brachii muscle

Surface anatomy of the right arm and

hand (posterior aspect).

Surface anatomy of the right arm (lateral aspect).

Triceps brachii muscle is strongly contracted.

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