The upper limb Muscles That Move the Pectoral

The upper limb

Muscles That Move the Pectoral Girdle n n n Originate on the axial skeleton and insert on the clavicle and scapula. Stabilize the scapula and move it to increase the arm’s angle of movements. Some of the superficial muscles of the thorax are grouped together according to the scapular movement they direct. q elevation, depression, protraction, or retraction

The muscles of back Superficial group n Trapezius n Latissimus dorsi n Levator scapulae n Rhomboideus Deep group n Erector spinae n Splenius n Thoracolumbar fascia

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The muscles of thorax Extrinsic muscles n Pectoralis major n Pectoralis minor n Serratus anterior Intrinsic muscles n Intercostales externi n Intercostales intimi

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The Muscles of Upper Limb Muscles of shoulder n Deltoid n Supraspinatus n Infraspinatus n Teres minor n Teres major n Subscapularis

Major muscles of shoulder Deltoid n n n Origin: lateral third of clavicle, acromion, and spine of scapula Insertion: deltoid tuberosity of humerus Action: abduction, flexion and extension, medial and lateral rotation of arm

Major muscles of shoulder Teres major n n n Origin: dorsal surface of inferior angle of scapula Insertion: crest of lesser tubercle of humerus Action: medially rotates and adducts arm

Arm and Forearm Muscles That Move the Elbow Joint/Forearm n n Anterior (flexor) compartment Posterior (extensor) compartment Anterior compartment q primarily contains elbow flexors Posterior compartment contains elbow extensors q the principal flexors n q biceps brachii, brachialis, and brachioradialis muscles that extend the elbow joint n triceps brachii and anconeus

Muscles of arm n Antererior group q q q n Biceps brachii Coracobrachialis Brachialis Posterior group q q triceps brachii anconeus

Muscles of arm Biceps brachii n Origin: long head, supraglenoid tubercle; short head, coracoid process n Insertion: radial tuberosity n Action: supinator of forearm, flexor of elbow joint, weak flexor of should joint

Muscles of arm Triceps brachii n Origin: q q q n n long head, infraglenoid tubercle lateral head, above groove for radial nerve medical head, below groove for radial nerve Insertion: olecranon of ulna Action: extends elbow joint, long head extends and adducts shoulder joint

Triceps brachii

Forearm Muscles Supinate and Pronate n n n Supinator muscle supinates the forearm. Biceps brachii supinates the forearm. Pronator teres and pronator quadratus pronate the forearm. Move the Wrist Joint, Hand, and Fingers n n Muscles in the forearm move the hand at the wrist and/or the fingers. Extrinsic muscles of the wrist and hand originate on the forearm, not the wrist or hand. Tendons of forearm muscles typically are surrounded by tendon (synovial) sheaths and held adjacent to the skeletal elements by strong fascial structures. At the wrist, the deep fascia of the forearm forms thickened, fibrous bands termed retinacula.

Muscles of forearm n Superficial layer q q Pronator teres Flexor carpi radialis Palmaris longus Flexor carpi ulnaris

Muscles of forearm Pronator teres n Origin: medical epicondyle of humerus and deep fascia of forearm n Insertion: middle of lateral surface of radius n Action: pronation of forearm and flexion of elbow

n Second layer Flexor digitorum superficials

n Third layer q q n Flexor digitorum profundus Flexor pollicis longus Fourth layer q Pronator quadratus Action: flex radiocarpal joint and fingers, pronate forearm

Lateral group (3) q q q Brachioradialis Extensor carpi radialis longus Extensor carpi radialis brevis

Posterior group (8) n Superficial layer (3) q q q Extensor digitorum Extensor digiti minimi Extensor carpi ulnaris Action: extension at wrist joint

Posterior group (8) Deep layer (5) n Supinator n Abductor pollicis longus n Extensor pollicis brevis n Extensor pollicis longus n Extensor indicis n Action: extend at wrist joint and fingers, and supinate forearm

Muscles of hand n Lateral group thenar (4) q q n n Action: flex, abduct, adduct and oppose thumb Medial group hypothenar (3) q q q n Abductor pollicis brevis Flexor pollicis brevis Opponens pollicis Adductor pollicis Abductor digiti minimi Flexor digiti minimi brevis Opponens digiti minimi Action: flex, abduct , and oppose little finger

Muscles of hand Intermedial group n Lumbricales (4) flex fingers at MP joints; extend fingers at IP joints n Palmar interossei (3) adduct fingers towards middle finger at MP joints n Dorsal interossei (3) abduct fingers away from middle finger at MP joints

Arteries of upper limb Axillary artery n n n Continuation of subclavian artery at lateral border of first rib Becomes brachial artery at lower border of teres major Divided into three parts by overlying pectoralis minor q q q First portion, above muscle－gives rise to thoracoacromial a. Second portion, behind muscle－gives rise to lateral thoracic a. Third portion, below muscle－gives rise to subscapular a. , anterior and posterior humeral circumflex a. ; the former then divides into throcodorsal a. and circumflex scapular a.

Arteries of upper limb Brachial artery n Continuation of axillary artery n Divides into radial and ulnar arteries at level of neck of radius n Branches q q q Deep brachial a. accompanies with radial nerve Superior ulnar collaeral a. accompanies with ulnar nerve Inferior ulnar collateral a.

Arteries of upper limb Radial artery and branches n Radial recurrent a. n Superfical palmar branch n Principal artery of thumb Ulnar artery and branches n Ulnar recurrent a. n Common interosseous artery q q n Anterior interossous a. Posterior interosseous a. Deep palmar branch

Arteries of upper limb Superficial palmar arch n Formed by ulnar artery and superficial palmar branch of radial artery n Curve of arch lies across the palm, level with the distal border of fully extended thumb n Gives rise to three common palmar digital arteries each then divides into two proper palmar digital arteries

Arteries of upper limb Deep palmar arch n Formed by radial artery and deep palmar branch of ulnar artery n Curve of arch lies across upper part of palmar at level with proximal border of extended thumb n Gives rise to three palmar metacarpal arteries

Veins of the upper limb Deep veins: accompany the arteries of the same region and bear similar names Superficial veins n Cephalic vein q q Arises from the lateral side of the dorsal venous rete of hand Ascends on radial side of the forearm to the elbow and then in the lateral side of biceps brachii furrow, continues up the arm in the deltopectoral groove and then to the infraclavicular fossa, where it pierces clavipectoral fascia to drain into axillary vein

n Basilic vein q q n Arises from the medial side of the dorsal venous rete of hand Ascends on the ulnar side of forearm to the elbow and then in the medial bicepital brachii furrow to middle of the arm where it pierces the deep fascia and joins the brachial vein or axillary vein Median cubital vein links cephalic vein and basilic vein in the cubital fossa. It is a frequent site for venipuncture to remove a sample of blood or add fluid to the blood

The lymphatic drainage of upper limb Lymphatic vessels n Superficial－follow the superficial veins, drain into supratrochlear and axillary lymph nodes n Deep－accompany main vessels, end in axillary lymph nodes n Cubital lymph node: lies above medial epicondyle of humerus n Axillary lymph node－arranged in five groups

Axillary lymph nodes Arranged in five groups n n Lateral lymph nodes lie around the distal end of axillary vein , receiving drainage from the arm, forearm, and hand Pectoral lymph nodes lie along lateral thoracic vessels, receive afferents from anterior thoracic wall including central and lateral portion of mamma Subscapular lymph node along subscapular vessels, receive lymph from nape and scapular region Efferents above three groups pass to central lymph node

n Central lymph node q n lie in fat of axillary fossa, receive drainage from all the above nodes, efferents pass to apical lymph node Apical lymph node q q q Lie in the apex of the axilla, along the proximal end of axillary vessels Receive drainage chiefly from central lymph node , upper portion of mamma Efferents form subclavian trunk, the right subclavian trunk joints the right lymphatic duct; left usually drains directly into thoracic duct

Brachial plexus Formation: n n Five roots: formed by anterior rami of C 5 -C 8 and T 1 spinal nerves, roots C 5 -C 7 give rise to long thoracic n. Three trunks q q q n n The upper trunk is formed by the joining of root C 4, C 5, C 6. The middle trunk is the continuation of root C 7. The lower trunk is formed by the joining of root C 8 and T 1. Six divisions: above clavicle, trunks form anterior and posterior divisions Three cords: below clavicle, divisions form three cords that surround the second portion of axillary a.

Position: passes through the scalene fissure to posterosuperior of subclavian artery, then enters the axilla to form lateral, medial and posterior cords Main branches n n Lateral cord q Musculocutaneous n. q Lateral root to median n. Medial cord q Medial root to median n. q Ulnar n. q Medial brachial cutaneous n. q Medial antebrachial cutaneous n.

n Posterior cord q q q radial n. axillary n. thoracodorsal n.

n Musculocutaneous Distribution: Biceps brachii, brachalis and coracobrachialis ‘BBC nerve’; skin on anterior aspect of forearm

Median nerve n n Distribution: Flexors of forearm except brachioradialis, flexor carpi ulnaris and ulnar half of flexor digitorum profundus, thenar except adductor pollicis, first two lumbricals; skin of thenar, central part of palm, palmar aspect of radial three and one-half fingers, including middle and distal fingers on dorsum. Injury: Apehand produces sign of benediction, in which the index and middle fingers cannot be flexed and the thumb cannot be opposed

Ulnar nerve n n Distribution: Flexor carpi ulnaris, ulnar half of flexor digitorum profundus, hypothenar muscles, interossei, 3 rd and 4 th lumbricals and adductor pollicis; skin of hypothenar, palmar surface of ulnar one and one-half fingers, ulnar half of dorsum of hand, posterior aspect of ulnar two and onehalf fingers Injury: clawhand

Radial nerve q q Distribution: Extensor muscles of arm and forearm, brachioradialis; skin on back of arm, forearm, and radial side of dorsum of hand radial two and one-half fingers Injury: Wristdrop

n Axillary q q Distribution: Deltoid and teres minor muscle; skin over deltoid and upper posterior aspect of arm Injury: results in deltoid and teres minor paralysis (loss of shoulder abdution and weel external rotation) with loss of sensation over the deltoid