Artery PDF

CHAPTER 20 Upper Limb I Bones. The bones of the upper limb include the clavicle, scapula, humerus, radius, ulna, carpal bones (scaphoid, lunate, triquetrum, pisiform, trapezium, trapezoid, capitate, and hamate), metacarpals, and phalanges (proximal, middle, and distal)....

CHAPTER 20 Upper Limb I Bones. The bones of the upper limb include the clavicle, scapula, humerus, radius, ulna, carpal bones (scaphoid, lunate, triquetrum, pisiform, trapezium, trapezoid, capitate, and hamate), metacarpals, and phalanges (proximal, middle, and distal). II Muscles (see Appendix 1) A. Anterior Axioappendicular Muscles include the pectoralis major, pectoralis minor, sub- clavius, and serratus anterior. B. Posterior Axioappendicular and Scapulohumeral Muscles include the trapezius, latissimus dorsi, levator scapulae, rhomboid major and minor, deltoid, supraspinatus, infraspinatus, teres minor, teres major, and subscapularis. C. Muscles of the Anterior (Flexor) Compartment of the Arm include the biceps brachii, brachialis, and coracobrachialis. D. Muscles of the Posterior (Extensor) Compartment of the Arm include the triceps and anconeus. E. Muscles of the Anterior (Flexor) Compartment of the Forearm include the pronator teres, flexor carpi radialis, palmaris longus, flexor carpi ulnaris, flexor digitorum superficialis, flexor digitorum profundus, flexor pollicis longus, and pronator quadratus. F. Muscles of the Posterior (Extensor) Compartment of the Forearm include the brachioradialis, extensor carpi radialis longus, extensor carpi radialis brevis, extensor digitorum, extensor digiti minimi, extensor carpi ulnaris, supinator, extensor indicis, abductor pollicis longus, extensor pollicis longus, and extensor pollicis brevis. G. Intrinsic Muscles of the Hand include the opponens pollicis, abductor pollicis brevis, flexor pollicis brevis, adductor pollicis, abductor digiti minimi, flexor digiti minimi brevis, opponens digiti minimi, lumbricals (first through fourth), dorsal interossei (first through fourth), and palmar interossei (first through third). III Arterial Supply (Figure 20-1) A. Subclavian Artery extends from the arch of the aorta to the lateral border of the first rib. The subclavian artery gives off the following branches. 1. Internal Thoracic Artery is continuous with the superior epigastric artery, which anastomoses with the inferior epigastric artery (a branch of the external iliac artery). This may provide a route of collateral circulation if the abdominal aorta is blocked (e.g., postductal coarctation of the aorta). 199 200 Chapter 20 A Superficial cervical artery Cervicodorsal trunk Dorsal scapular artery Thyrocervical trunk Suprascapular artery Vertebral artery Axillary artery Right subclavian artery (begins lateral to Right and left common carotid arteries border of first rib) Left subclavian artery Thoracoacromial artery Brachiocephalic trunk Arch of aorta Posterior First Circumflex humeral artery rib Internal thoracic artery Anterior Subscapular artery Deltoid (ascending) branch Brachial artery Lateral thoracic artery (begins at inferior border of teres major) Profunda brachii artery (deep artery of arm) Superior ulnar collateral artery Inferior ulnar collateral artery Middle Collateral arteries Radial Radial recurrent artery Anterior Ulnar recurrent arteries Posterior Common interosseous artery Radial artery Ulnar artery Anterior interosseous artery Deep palmar arch Superficial palmar arch B C Dorsal scapular artery Radial artery Anterior Suprascapular artery Ulnar artery interosseous Levator scapulae artery Superficial palmar branch Rhomboid Radial artery Palmar minor carpal arch Princeps Deep palmar Axillary artery pollicis arch Subscapular Palmar artery metacarpal Anastomoses arteries Circumflex with intercostal scapular artery Superficial arteries palmar arch Thoracodorsal Radialis artery Common palmar indicis Brachial artery digital arteries Proper palmar Teres major digital artery gives rise to a dorsal branch Figure 20-1 A: Arterial supply of the upper limb (anterior view). B: Diagram of the collateral circulation around the shoulder (posterior view). C: Arterial supply of the hand (anterior palmar view).  Upper Limb 201 2. Vertebral Artery 3. Thyrocervical Trunk has three branches. a. Suprascapular artery, which participates in collateral circulation around the shoulder b. Transverse cervical artery, which participates in collateral circulation around the shoulder c. Inferior thyroid artery B. Axillary Artery is a continuation of the subclavian artery and extends from the lateral border of the first rib to the inferior border of the teres major muscle. The tendon of the pectoralis minor muscle crosses the axillary artery anteriorly and divides the axillary artery into three distinct parts (i.e., the first part is medial, the second part is posterior, and the third part lateral to the muscle). The axillary artery gives off the following branches. 1. First Part a. Superior thoracic artery 2. Second Part a. Thoracoacromial artery is a short, wide trunk that divides into four branches: Acromial, del- toid, pectoral, and clavicular. b. Lateral thoracic artery 3. Third Part a. Anterior humeral circumflex artery b. Posterior humeral circumflex artery c. Subscapular artery, which gives off the circumflex scapular artery and the thoracodorsal artery C. Brachial Artery is a continuation of the axillary artery and extends from the inferior border of the teres major muscle to the cubital fossa, where it ends in the cubital fossa opposite the neck of the radius. The brachial artery gives off the following branches. 1. Deep Brachial Artery a. A fracture of the humerus at midshaft may damage the deep brachial artery and radial nerve as they travel together on the posterior aspect of the humerus in the radial groove. b. The deep brachial artery ends by dividing into the middle collateral artery and radial col- lateral artery. 2. Superior Ulnar Collateral Artery runs with the ulnar nerve posterior to the medial epicondyle and anastomoses with the posterior ulnar recurrent artery to participate in collateral circulation around the elbow. 3. Inferior Ulnar Collateral Artery anastomoses with the anterior ulnar recurrent artery to partici- pate in collateral circulation around the elbow. 4. Radial Artery gives off the following branches. a. Recurrent radial artery anastomoses with the radial collateral artery. b. Palmar carpal branch c. Dorsal carpal branch d. Superficial palmar branch completes the superficial palmar arch. e. Princeps pollicis artery divides into two proper digital arteries for each side of the thumb. f. Radialis indicis artery g. Deep palmar arch is the main termination of the radial artery and anastomoses with the deep palmar branch of the ulnar artery. It gives rise to three palmar metacarpal arteries, which join the common palmar digital arteries from the superficial arch. 5. Ulnar Artery gives off the following branches. a. Anterior ulnar recurrent artery b. Posterior ulnar recurrent artery c. Common interosseous artery, which divides into the anterior interosseous artery and posterior interosseous artery. The posterior interosseous artery gives rise to the recurrent interosseous artery. d. Palmar carpal branch e. Dorsal carpal branch f. Deep palmar branch completes the deep palmar arch. 202 Chapter 20 g. Superficial palmar arch is the main termination of the ulnar artery and anastomoses with the superficial palmar branch of the radial artery. It gives rise to three common palmar digital arteries, each of which divides into proper palmar digital arteries, which run distally to supply the adjacent sides of the fingers. D. Collateral Circulation exists in the upper limb in the following regions. 1. Collateral Circulation Around the Shoulder a. Thyrocervical trunk → transverse cervical artery → circumflex scapular artery → subscapular artery → axillary artery b. Thyrocervical trunk → suprascapular artery → circumflex scapular artery → subscapular artery → axillary artery 2. Collateral Circulation Around the Elbow involves the following pathways. a. Superior ulnar collateral artery → posterior ulnar recurrent artery b. Inferior ulnar collateral artery → anterior ulnar recurrent artery c. Middle collateral artery → recurrent interosseus artery d. Radial collateral artery → recurrent radial artery 3. Collateral Circulation in the Hand involves the following pathway. a. Superficial palmar arch → deep palmar arch E. Clinical Considerations 1. Subclavian Steal Syndrome refers to retrograde flow in the vertebral artery due to an ipsilateral subclavian artery stenosis. The subclavian artery stenosis results in lower pressure in the distal subclavian artery. As a result, blood flows from the contralateral vertebral artery to the basilar artery and then in a retrograde direction down the ipsilateral vertebral artery away from the brainstem. Although this may have deleterious neurologic effects, the reversed vertebral artery blood flow serves as an important collateral circulation for the arm in the setting of a significant stenosis or occlusion of the subclavian artery. The most common cause for a subclavian steal syndrome is ath- erosclerosis. Subclavian steal is more common on the left side probably due to a more acute origin of the subclavian artery, which results in increased turbulence and accelerated atherosclerosis. 2. Placement of Ligatures. A surgical ligature may be placed on the subclavian artery or axillary artery between the thyrocervical trunk and subscapular artery. A surgical ligature may also be placed on the brachial artery distal to the inferior ulnar collateral artery. A surgical ligature may not be placed on the axillary artery between the subscapular artery and the deep brachial artery. 3. In order to control profuse bleeding due to trauma of the axilla (e.g., a stab or bullet wound), the third part of the axillary artery may be compressed against the humerus in the inferior part of the lateral wall of the axilla. If compression is required more proximally, the first part of the axillary artery may be compressed at its origin by downward pressure in the angle between the clavicle and the inferior attachment of the sternocleidomastoid muscle. 4. Percutaneous Arterial Catheterization employs the brachial artery (if the femoral artery approach is unavailable). The left brachial artery is preferred because approaching from the left side allows access to the descending aorta without crossing the right brachiocephalic trunk and left common carotid arteries, thereby reducing the risk of stroke. 5. Blood Pressure. The brachial artery is used to measure blood pressure by inflating a cuff around the arm, which compresses and occludes the brachial artery against the humerus. A stethoscope is placed over the cubital fossa and the air in the cuff is gradually released. The first audible sound indicates systolic pressure. The point at which the pulse can no longer be heard indicates the diastolic pressure. In order to control profuse bleeding due to trauma, the brachial artery may be compressed near the middle of the arm medial to the humerus.