The Upper Limb Lecture 1.Pdf
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The upper limb Muscles That Move the Pectoral Girdle 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. elevation, depression, protraction, or retraction The muscles of back Superficial group Trapezius Latissimus dorsi Levator scapulae Rhomboideus Deep group Erector spinae Splenius Thoracolumbar fascia The muscles of thorax Extrinsic muscles Pectoralis major Pectoralis minor Serratus anterior Intrinsic muscles Intercostales externi Intercostales interni Intercostales intimi The Muscles of Upper Limb Muscles of shoulder Deltoid supraspinatus Infraspinatus Teres minor Teres major subscapularis Major muscles of upper limb Deltoid Origin: lateral third of clavicle, acromion, and spine of scapula Insertion: deltoid tuberosity of humerus Action: abducts,flexes and medically rotates, extends, and laterally rotates arm Teres major Origin: dorsal surface of inferior angle of scapula Insertion: crest of lesser tubercle of humerus Action: medially rotates and adducts arm Foramen axillare laterale et mediale Arm Muscles That Move the Shoulder/Elbow Joint (Flexor) compartment Posterior (extensor) compartment Anterior compartment primarily contains shoulder/elbow flexors Posterior compartment contains elbow extensors the principal flexors biceps brachii, brachialis, and brachioradialis muscles that extend the elbow joint triceps brachii and the anconeus Muscles of arm Antererior group Biceps brachii Coracobrachialis Brachialis Posterior group – triceps brachii Biceps brachii Origin: long head, supraglenoid tubercle; short head, coracoid process Insertion: radical tuberosity Action: supinator of forearm, flexor of elbow joint, weak flexor of should joint Pronator teres Origin: medical epicondyle of humerus and deep fascia of forearm Insertion: middle of lateral surface of radius Action: pronation of forearm and flexion of elbow Triceps brachii Origin: long head, infraglenoid tubercle; lateral head, above groove for radical n., medical head, below groove for radical n. Insertion: olecranon of ulna Action: extends elbow joint), long head can extend and adduct shoulder joint Posterior of the arm Surface anatomy M. triceps brachii caput longum, medialis, lateralis Surface elements Skin thick and movable Subcutaneous tissue well expressed n. cutaneus brachii posterior n. cutaneus brachii lateralis inferior n. cutaneus antebrachii posterior Deep structures А. Fascia brachialis - Thick, thins distally B. Neurovascular bundles 1. Upper - in canalis humero-muscularis, between: - sulcus n. radialis - medial and lateral head of m. triceps brachii 1.1. n. radialis – lies on the humerus - n. cutaneus brachii lateralis inerior - n. cutaneus antebrachii posterior - rr. musculres 1.2. a. profunda brachii - a. collateralis media - collateralis radialis Lower neurovascular bundle behind medial epicondyle n. ulnaris a. collateralis ulnaris inferior Elbow region Anterior elbow Surface anatomy Three eminences Two grooves Elements Lateral groove - v. cephalica, n. cutaneus antebrachii lateralis Medial groove – v. basilica, n. cutaneus antebrachii medialis V. mediana cubiti Deep structures А. Muscles Flexors of forearm – medial eminence Extensors of forearm – lateral eminence Brachial muscles, mm. biceps, brachialis – middle eminence Deep structures B. Vessels and nerves Medial bundle - between m. biceps brachii and pronator teres - a.v. brachialis, n. medianus Lateral bundle - between m. brachialis and brachioradialis - n. radialis, a. collateralis radialis, a. recurrens radialis C. Cubital fossa Boundaries - m. brachioradialis (lateral), m. pronator teres (medial) Content - tendo m. brachialis, m. biceps brachii, bursa bicipitoradialis Layers of the elbow Venous 1 v. cephalica 2 v. basilica 3 v. mediana cubiti Apponeurotic 1 aponeurosis bicipis 2 tendo m. biceps brachii Neurovascular 1 a. brachialis 2 n. medianus Muscle 1 m. supinator 2 m. brachialis 3 tendo m. biceps brachii Bone 1 humerus 2 radius 3 ulna Anterior elbow Arteries of upper limb Axillary artery 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 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. divides into throcodorsal a. and circumflex scapular a. anterior and posterior humeral circumflex a.; Brachial artery Continuation of axillary artery Divides into radial and ulnar arteries at level of neck of radius Branches Deep brachial a. accompanies radial nerve Superior ulnar collaeral a. accompanies ulnar nerve Inferior ulnar collateral a. Radial artery and branches Radial recurrent a. Superfical palmar branch Principal artery of thumb Ulnar artery and branches Ulnar recurrent a. Common interosseous artery Anterior interossous a. Posterior interosseous a. Deep palmar branch Basilic vein 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 Superficial-follow the superficial veins, drain into supratrochlear and axillary lymph nodes Deep-accompany main vessels, end in axillary lymph nodes Lymph nodes Cubital lymph node: lies above medial epicondyle of humerus Axillary lymph node-arranged in five groups Axillary lymph nodes Arranged in five groups 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 Brachial plexus Formation: Five roots: anterior rami of C5-C8 and T1 spinal nerves, roots C5- C7give rise to long thoracic n. Three trunks Upper trunk formed by the joining of roots C4,C5,C6. Middle trunk continuation of root C7. Lower trunk formed by the joining of roots C8 and T1. 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 Lateral cord Musculocutaneous n. Lateral root to median n. Medial cord Medial root to median n. Ulnar n. Medial brachial cutaneous n. Medial antebrachial cutaneous n. Posterior cord radial n. axillary n. thoracodorsal n. Musculocutaneous nerve Supplies: Muscles -‘BBC nerve’ Biceps brachii, Brachalis Coracobrachialis; skin on the anterior aspect of forearm Median nerve Supplies: Flexors of forearm except brachioradialis, Flexor carpi ulnaris flexor digitorum profundus - ulnar half Thenar except adductor pollicis, two lateral 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: Ape hand produces sign of benediction, the index and middle fingers cannot be flexed and the thumb cannot be opposed Ulnar nerve Supplies: flexor carpi ulnaris, ulnar half of flexor digitorum profundus, hypothenar muscles, interossei, 3rd and 4th 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 one-half fingers Injury: claw hand Radial Supplies: Extensor muscles of arm and forearm, Brachioradialis; skin on back of arm, forearm, and radial side of dorsum of hand and radial two and one- half fingers Injury: Wrist drop Axillary nerve Supplies: Deltoid and teres minor muscle; skin over deltoid and upper posterior aspect of arm Injury: deltoid and teres minor paralysis (loss of shoulder abdution and wheel external rotation) loss of sensation over the deltoid Forearm Muscles Supinate and Pronate 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 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. The forearm extends from elbow to wrist. It posses two bones radius laterally & Ulna medially. The two bones are connected together by the interosseous membrane. This membrane allows movement of Pronation and Supination while the two bones are connected together.