Upper Limb Arteries: Subclavian and Axillary

• The upper limb's vascular anatomy includes arteries and veins.

Arteries of the Upper Limb

• The main arteries include the subclavian, axillary, brachial, ulnar, and radial arteries, as well as the palmar arches.

Subclavian Artery

• The right subclavian artery originates from the brachiocephalic artery.
• The left subclavian artery originates from the arch of the aorta.
• The subclavian artery continues as the axillary artery at the lateral border of the 1st rib.

Axillary Artery

• The axillary artery begins at the lateral border of the 1st rib, as a continuation of the subclavian artery.
• It continues as the brachial artery at the lower border of the teres major muscle.
• The axillary artery is divided into three parts by the pectoralis minor muscle.
• The axillary artery is enclosed within the axillary sheath.
• The axillary artery is closely related to the cords of the brachial plexus and their branches.

Axillary Artery - 1st Part

• It extends from the lateral border of the 1st rib to the upper border of the pectoralis minor muscle.
• It is related anteriorly to the pectoralis major muscle, and laterally to the cords of the brachial plexus.
• The 1st part has one branch: the highest thoracic artery.

Axillary Artery - 2nd Part

• It lies behind the pectoralis minor muscle.
• It is related medially, laterally, and posteriorly to the corresponding cord of the brachial plexus.
• The 2nd part has two branches: the thoracoacromial and lateral thoracic arteries.

Axillary Artery - 3rd Part

• Extends from the lower border of the pectoralis minor to the lower border of the teres major muscle.
• Is related medially, laterally, and posteriorly to the branches of the cords of the brachial plexus.
• The 3rd part gives three branches: subscapular, anterior circumflex humeral, and posterior circumflex humeral.

Brachial Artery

• The brachial artery is a continuation of the axillary artery at the lower border of the teres major muscle.
• It provides the main arterial supply for the arm.
• It terminates opposite the neck of the radius by dividing into radial and ulnar arteries.
• Anterior relations include being crossed from above downward by the medial cutaneous nerve of the forearm, the median nerve, and the bicipital aponeurosis.
• Posterior relations include the triceps, coracobrachialis, and brachialis muscles.
• Medial relations include the basilic vein, ulnar and median nerves.
• Lateral relations include the coracobrachialis and biceps muscles.
• Branches include muscular branches, nutrient artery to the humerus, profunda brachii, superior ulnar collateral, and inferior ulnar collateral arteries.

Ulnar Artery

• It is the larger of the two terminal branches of the brachial artery.
• It begins in the cubital fossa at the level of the neck of the radius.
• It descends through the anterior compartment of the forearm.
• Enters the palm, in front of the flexor retinaculum, with the ulnar nerve.
• Ends by forming the superficial palmar arch, anastomosing with the superficial palmar branch of the radial artery.
• Its branches are muscular branches, recurrent branch for anastomosis around the elbow joint, common interosseous artery (giving anterior and posterior interosseous arteries), and a branch to anastomose around the wrist joint.

Radial Artery

• The radial artery is the smaller of the two terminal branches of the brachial artery.
• It begins in the cubital fossa at the level of the neck of the radius.
• It descends downward and laterally.
• It leaves the forearm by winding around the lateral aspect of the wrist to reach the dorsum of the hand.
• Its branches include muscular branches, recurrent branch for anastomosis around the elbow joint, and the superficial palmar branch, which joins the ulnar artery to form the superficial palmar arch.

Arteries of the Palm

• Ulnar artery enters anterior to the flexor retinaculum, and lateral to the ulnar nerve and pisiform bone; it gives a deep branch and continues as the superficial palmar arch.
• Radial artery leaves the dorsum of the hand; it continues as the deep palmar arch, and gives arteriae radialis indicis and arteria princeps pollicis.

Superficial Palmar Arch

• The superficial palmar arch is the direct continuation of the ulnar artery, as it curves laterally behind the palmar aponeurosis.
• Is completed by a branch from the radial artery.
• Lies approximately at the level of the distal border of the extended thumb.
• Gives digital arteries from its convexity to supply the fingers.

Deep Palmar Arch

• Is a continuation of the radial artery as it curves medially beneath long flexor tendons, front of the metacarpal bones and interosseous muscles.
• Is completed on the medial side by a deep branch of the ulnar artery
• Lies at a level of the proximal border of the extended thumb.
• Sends superiorly branches to share in anastomosis around the wrist joint and inferiorly to join branches of the superficial palmar arch.
• The superficial palmar arch is more distal than the deep palmar arch.

Veins of the Upper Limb

• Veins are divided into superficial and deep sets.
• The two sets anastomose frequently.
• Superficial veins are placed immediately beneath the skin, in the superficial fascia.
• Deep veins accompany the arteries.
• The dorsal digital veins drain into dorsal metacarpal veins.

Superficial Veins: Dorsal Venous Arch

• Drains into dorsal metacarpal veins, uniting to form a dorsal venous arch or network
• Dorsal venous network lies on the dorsum of the hand, in the subcutanous tissue, proximal to the metacarpophalangeal joints.
• Drains into the cephalic vein laterally, and basilic vein medially.

Cephalic Vein

• Arises from the lateral end of the dorsal venous arch of the hand.
• Ascends on the radial side of the forearm to the elbow.
• Continues up the arm in the deltopectoral groove.
• Pierces clavipectoral fascia to drain into the axillary vein

Basilic Vein

• Arises from the medial side of the dorsal venous arch of the hand.
• Ascends on the ulnar side of the forearm to the elbow.
• In the middle of the arm, it pierces the deep fascia and joins the brachial or axillary vein.

Median Cubital Vein

• Links the cephalic and basilic veins in the cubital fossa.
• It is a frequent site for venipuncture.

Deep Veins

• Accompany the arteries of the same region and bear similar names.
• Venae comitantes are arranged in pairs on either side of the corresponding artery, connected by short transverse branches.
• The superficial and deep palmar arterial arches have corresponding venae comitantes that constitute superficial and deep palmar venous arches.
• Deep veins of the forearm are venae comitantes of radial and ulnar veins.
• The brachial veins are placed one on either side of the brachial artery.
• The axillary vein Begins at the lower border of the Teres major, as the continuation of the basilic vein and Ends at the outer border of the first rib as the subclavian vein.
• Receives the brachial veins and, close to its termination, the cephalic vein.
• The subclavian vein Is the continuation of the axillary vein. Extends from the outer border of the first rib to the sternal end of the clavicle, where it unites with the internal jugular to form the brachiocephalic (innominate) vein.