Dorsal surface of the upper limb

1. Dorsal surface of the upper limb 山东大学医学院 解剖教研室 李振华

2. The Muscles of Back Superficial group • Trapezius 斜方肌 • Levator scapulae 肩胛提肌 • Rhomboid minor 小菱形肌 • Rhomboid major 大菱形肌 • Latissimus dorsi 背阔肌 • Thoracolumbar fascia胸腰筋膜

3. The Muscles of Back Deep group • Splenius 夹肌 • Erector spinae 竖脊肌

4. Major Muscles of Back Trapezius斜方肌 • Origin: superior nuchal line, external occipital protuberance, ligamentum nuchae and spinous processes of seventh cervical and all thoracic vertebrae • Insertion: lateral third of clavicle, acromion, and spine of scapular • Acton: upper fibers elevate scapula, lower fibers depress scapula; if scapula is fixed, one side acting along, draws head toward the same side, and turn face to opposite side; both sides together, draw head directly backward • Nerve supply: accessory nerve (Ⅺ cranial nerve)

5. Major Muscles of Back Latissimus dorsi背阔肌 • Origin: • Spinous processes of lower six thoracic and all lumbar vertebrae • Median sacral crest • Posterior part of iliac crest • Insertion: floor of intertubercular groove of humerus. • Action: trunk fixed, extends, adducts and medially rotates arm ; arm fixed, elevates trunk. • Nerve supply: thoracodorsal nerve

6. Thoracolumbar Fascia 胸腰筋膜 Anterior layer Middle layer Posterior layer

7. Trapezius Levator scapular Deltoid Ausculatory triangle Rhomboideus Latissimus dorsi Thoracolumbar fascia Inferior lumbar triangle

8. Superior lumber triangle 腰上三角

9. The Muscles of shoulder • Deltoid 三角肌 • Supraspinatus 冈上肌 • Infraspinatus 冈下肌 • Teres minor 小圆肌 • Teres major 大圆肌 • Subscapularis 肩胛下肌

10. Deltoid 三角肌 • Origin: lateral third of clavicle, acromion, and spine of scapula • Insertion: deltoid tuberosity of humerus • Action: abducts the arm，anterior fibers flex and medially rotate arm; posterior fibers extend and laterally rotate arm • Nerve supply: axillary nerve

11. Teres major 大圆肌 • Origin:dorsal surface of inferior angle of scapula • Insertion:crest of lesser tubercle of humerus • Action:medially rotates and adducts arm • Nerve supply: subscapular nerve

12. Contents of posterior osseofascial compartment of the arm • Muscle:Triceps brachii肱三头肌 • Nerve supply to the muscle:Radial nerve • Blood supply: • deep brachial a. • ulnar collateral a. • Structures passing through the compartment: • radial nerve • ulnar nerve

13. Triceps brachii 肱三头肌 • Origin: • Long head from infraglenoid tubercle of scapula • lateral head from above the spiral groove • medical head from below the spiral groove • Insertion: olecranon of ulna • Action: extends elbow joint, long head can extend and adduct shoulder joint • Nerve supply: Radial nerve

14. Humeromuscular tunnel 肱骨肌管 • Composition: Formed by triceps brachiiand groove for radial nerve of humerus • Structures passing through the tunnel • Radial nerve • Deep brachial artery

15. Radial nerve 桡神经 • Origin: From the posterior cord of the brachial plexus • Course: Winds around the back of the arm in the spinal groove of the back of the humerus between the heads of the triceps. It pierces the lateral fascial septum above the elbow and divides into superficial and deep branches. • Distribution: Tricps andskin on back of arm

16. Contents of posterior osseofascial compartment of the forearm • Muscle (10) • Blood supply to the muscles: posterior interosseous artery. • Nerve supply to the muscles: radial nerve

17. Posterior group Muscles of forearm • Superficial layer (5) • Extensor carpi radialis longus 桡侧腕长伸肌 • Extensor carpi radialis brevis 桡侧腕短伸肌 • Extensor digitorum 指伸肌 • Extensor digiti minimi 小指伸肌 • Extensor carpi ulnaris 尺侧腕伸肌

18. Posterior group Muscles of forearm • Deep layer (5) • Supinator 旋后肌 • Abductor pollicis longus 拇长展肌 • Extensor pollicis brevis 拇短伸肌 • Extensor pollicis longus 拇长伸肌 • Extensor indicis 示指伸肌 • Action: extend radiocapral joint and fingers, and supinate forearm

19. Supinator 旋后肌 • Origin: lateral epicondyle of humerus and upper part of lateral border of ulna • Insertion: upper third of anterior surface of radius • Action: supination of forearm • Nerve supply: radial nerve

20. Nerves and vessels of posterior osseofascial comprtment of the forearm • Deep branch of radial nerve • Distribution: • Extensor muscles of forearm • brachioradialis • skin on back of forearm • Injury: Wristdrop • Posterior interosseous artery

21. Skin incision • Make the skin incision shown in figure and remove the skin and tela superficial fascia. Reflect the skin as far as the midaxillary line. • As you skin the back, notice small nerves and vessels piercing the muscles and coursing upward in to the skin.

22. The Muscles of Back Accessory n. Retract the should posterior to relax the trapezius and separate the muscle from underlying structures by passing your hand or scissors beneath the muscle, cut the muscle very close to the spinous processes all the way to inion and cut its attachment to the scapular spin and acromion, leaving the trapezius attached only to the clavicle.

23. Back and should region • Define the borders of the deltoid muscle and detach the muscle from the spine and the acromion, leaving the muscle attached of clavicle. • Reflecting the deltoid anteriorly, identify the axiiary n. and posterior circumflex humeral a. on its deep surface. Note that these structures pass through the quadrangular space.

24. Posterior compartment of the arm • Identify the long head of the triceps brachii and note that it passes between the teres minor and teres major. • Using your fingers, separate the long head from the lateral head of the triceps. • Identify the three heads of the triceps, the long, lateral and medial. • Expose the radial n. and deep brachial a. by carefully cutting the lateral head of the triceps. The nerve and artery lie in the humeromuscular tunnel.

25. Suprascapular n.& a. Supraspinatus Teres minor Axillary n. Infraspinatus Posterior humeral circumflex a. Deep brachial a. Radial n. Teres major Back and should region

26. Posterior compartment of the arm Radial n. Deep brachial a.

27. Superficial extensors • Identify and clean the extensor carpi radialis longus, and extensor carpi radialis brevis. • More medially, clean the extensordigitorum, extensor digiti minimi, and extensor carpi ulnaris. • Study the arrangement of the tendons as they pass through the extensor retinaculum. • Once you have thoroughly studied their arrangement, cut the retinaculum and reflect the muscle tendons medially to expose the deeper muscles.

28. Superficial extensors • Extensor carpi radialis longus • 桡侧腕长伸肌 • Extensor digiti minimi • 小指伸肌 Extensor carpi radialis brevis 桡侧腕短伸肌 Extensor digitorum指伸肌 • Extensor carpi ulnaris • 尺侧腕伸肌

29. Deep extensors • Identify and clean the abductor pollicis longus, extensor pollicis brevis, and extensor pollicis longus. Then clean the supinator and the extensor indicis (to index finger). • Note that the deep branch of the radial nerve pierces the supinator and then runs along the interosseous membrance supplying innervation to the extensors.

30. Deep extensors Supinator Abductor pollicis longus Extensor pollicis brevis Extensor pollicis longus Extensor indicis

31. Cephalic v. Radial n. Basilic v. Ulnar n.

32. Muscles Trapezius 斜方肌 Levator scapulae 肩胛提肌 Rhomboideus 菱形肌 Latissimus dorsi 背阔肌 Thoracolumbar fascia 胸腰筋膜 Deltoid 三角肌 Supraspinatus 冈上肌 Infraspinatus 冈下肌 Teres minor 小圆肌 Teres major 大圆肌 Triceps brachii 肱三头肌 Extensor carpi radialis longus 桡侧腕长伸肌 Extensor carpi radialis brevis 桡侧腕短伸肌 Extensor digitorum 指伸肌 Extensor digiti minimi 小指伸肌 Extensor carpi ulnaris 尺侧腕伸肌 Supinator 旋后肌 Abductor pollicis longus 拇长展肌 Extensor pollicis brevis 拇短伸肌 Extensor pollicis longus 拇长伸肌 Extensor indicis 示指伸肌 ★You must identify follow structures！

33. ★You must identify follow structures！ • Vessels • Suprascapular a. • Posterior humeral circumflex a. • Deep brachial a. • Nerves • Accessory n. • Suprascapular n. • Axillary n. • Radial n. • deep branch of the radial n.