BLOOD VESSELS OF FOREARM

Arteries.

Main arteries
• Ulnar artery
• Radial Artery


The Radial Artery
• It begins in the cubital fossa, opposite the neck of the radius.
• The proximal part of the radial artery is overlapped by the fleshy belly of the brachioradialis muscle.
• The radial artery lies on muscle until it comes into contact with the distal end of the radius, where it is covered only by superficial and deep fascia and skin.
• It leaves the forearm by winding around the lateral aspect of the radius.
• It passes posteriorly between the lateral collateral ligament of the wrist joint and the tendons of the abductor pollicis longus and extensor pollicis brevis muscles.
• The radial artery crosses the floor of the anatomical snuffbox formed by the scaphoid and trapezium bones.
• It enters the palm of the hand by passing between the heads of the first dorsal interosseous muscle.
• The radial artery gives off the princeps pollicis artery and the radialis indicis artery (arteries to the thumb and index fingers).
• The radial artery then passes between the two heads of adductor pollicis muscle and ends by completing the deep palmar arterial arch in conjunction with the ulnar artery.
Branches of the Radial Artery
• Muscular branches of the radial artery supply muscles on the lateral side of the forearm.

The Radial Recurrent Artery
• This arises from the lateral side of the radial artery, just distal to its origin.
• It ascends between the brachioradialis and the brachialis muscles.
• It supplies these muscles, the elbow joint, and anastomoses with the radial collateral artery, a branch of the profunda brachii artery.

The Superficial Palmar Branch
• This arises at the distal end of the radius, just proximal to the wrist.
• It passes through and sometime over the muscles of the thenar eminence, which it supplies.
• It usually anastomoses with the terminal part of the ulnar artery to form a superficial palmar arterial arch.

The Dorsal Carpal Branch
• This runs medially across the dorsal surface of the wrist, deep to the extensor tendons.
• Here it anastomoses with the dorsal carpal branch of the ulnar artery and with the terminations of the anterior and posterior interosseous arteries to form the dorsal carpal arch.

Palmar Metacarpal Arteries
• There are three of these arteries and they arise from the deep palmar arch and run distally, where they joint the common palmar digital arteries, which arise from the superficial palmar arterial arch.

The Ulnar Artery
• This artery begins near the neck of the radius, just medial to the biceps brachii tendon.
• It is the larger of the two terminal branches of the brachial artery.
• The ulnar artery passes inferomedially deep to the pronator teres muscle.
• With the median nerve, the ulnar artery passes between the ulnar and radial heads of the flexor digitorum superficialis muscle.
• About midway between the elbow and the wrist, the ulnar artery crosses posterior to the median nerve to reach the medial side of the forearm, where it lies on the flexor digitorum superficialis muscle.
• In the distal 2/3 of the forearm, the ulnar artery lies lateral to the ulnar nerve.
• It leaves the forearm by passing superficial to the flexor retinaculum on the lateral side of the pisiform bone.
• At the wrist, the ulnar artery and nerve lie lateral to the tendon of flexor carpi ulnaris muscle.
• Here, they are covered only by fascia and skin.
Branches of the Ulnar Artery
Anterior Ulnar Recurrent Artery
• This arises from the ulnar artery, just inferior to the elbow joint.
• It runs superiorly between the brachialis and pronator teres muscles.
• It supplies these muscles and anastomoses with the inferior ulnar collateral artery.

The Posterior Ulnar Recurrent Artery
• This arises from the ulnar artery distal to the anterior ulnar recurrent artery.
• It passes superiorly, posterior to the medial epicondyle of the humerus, where it lies deep to the tendon of the flexor carpi ulnaris muscle.
• It supplies the adjacent muscles and then takes part in the arterial anastomosis around the elbow.

The Common Interosseous Artery
• This is a short branch of the ulnar artery.
• It arises from the distal part of the cubital fossa and divides into the anterior and posterior interosseous arteries.

The Anterior Interosseous Artery
• This artery passes distally on the interosseous membrane to the proximal border of the pronator quadratus muscles.
• Here, it pierces the membrane and continues distally to joint the dorsal carpal arch.

The Posterior Interosseous Artery
• This artery passes posterior between the bones of the forearm, just proximal to the interosseous membrane.
• It supplies the adjacent muscles and then gives off the posterior interosseous recurrent artery, which passes superiorly, posterior to the lateral epicondyle of the humerus and participates in the arterial anastomosis around the elbow.

The Palmar Carpal Branch of the Ulnar Artery
• This arises just proximal to the pisiform bone.
• It passes across the anterior aspect of the wrist, deep to the tendon of flexor digitorum profundus muscle.
• This branch anastomoses with the palmar carpal branch of the radial artery and forms the palmar carpal arch.

The Dorsal Carpal Branch of the Ulnar Artery
• This arises just proximal to the pisiform bone.
• It passes across the dorsal surface of the wrist, deep to the extensor tendons, where it anastomoses with the dorsal carpal branch of the radial artery to form the dorsal carpal arch.

The Superficial Branch of the Ulnar Artery
• This artery continues into the palm as the superficial palmar arch.

The Deep Palmar Branch of the Ulnar Artery
• This branch passes deeply in the hand, where it anastomoses with the radial artery and completes the deep palmar arch.

The Superficial Palmar Arterial Arch
• It is formed mainly by the ulnar artery.
• It gives rise to 3 common palmar digital arteries that anastomoses with the palmar metacarpal arteries from the deep palmar arch.
• Each common palmar digital artery divides into a pair of proper digital arteries, which runs along the sides of the 2nd to 4th digits.

The Deep Palmar Arterial Arch
• This lies across the metacarpal bones just distal to their bases.
• This if formed mainly by the radial artery.
• It is about a fingerbreadth closer to the wrist than the superficial palmar arterial arch.
• It gives rise to 3 common palmar digital arteries.


Arteries of the forearm.



Arteries of the hand.
Veins of the Upper Limb
Veins of the Hand
• The superficial and deep palmar arterial arches are accompanied by venae comitantes, known as the superficial and deep venous arches.
• The dorsal digital veins drain into three dorsal metacarpal veins, which unite to form a dorsal venous network.
• Located superficial to the metacarpus, this network is prolonged proximally as the cephalic vein, which winds superiorly around the lateral border of the forearm to its anterior surface.
Veins of the Arm and Cubital Fossa
• Two deep brachial veins accompany the brachial artery.
• These veins and their connections encompass the artery in an anastomotic network. The pulsations of the brachial artery help to move the blood through this venous network.
• The brachial veins begin at the elbow, by the union of the venae comitantes of the ulnar and radial arteries, and they end in the axillary vein.
• The brachial veins contain valves and are connected at intervals by short transverse branches.
• Sometimes, the deep veins join to form one brachial vein during part of their course.
• The two main superficial veins of the arm are the cephalic and basilic veins.

The Cephalic Vein (p. 549)
• This vein is located in the superficial fascia along the anterolateral surface of the biceps brachii muscle and is often visible through the skin.
• Superiorly the cephalic vein passes between the deltoid and pectoralis major muscles and through the deltopectoral triangle, where it empties into the axillary vein.

The Basilic Vein (p. 549)
• This vein is also located in the superficial fascia and passes on the medial side of the inferior part of the arm.
• Near the junction of the middle and inferior thirds of the arm, the basilic vein passes deep to the brachial fascia and runs superiorly to the axilla.
• This vein becomes the axillary vein.

The Median Cubital Vein (p. 549)
• This vein forms the communication between the basilic and cephalic veins in the cubital fossa.
• It lies anterior to the bicipital aponeurosis.
The Axillary Vein (p. 527)
• This large vessel lies on the medial side of the axillary artery.
• It completely overlaps the artery anteriorly when the arm is abducted.
• The axillary vein, the continuation of the basilic vein, begins at the inferior border of the teres major muscle.
• It ends lateral to the first rib, where it becomes the subclavian vein.
• The axillary vein receives tributaries that correspond to the branches of the axillary artery and at the inferior margin of the subscapularis muscle, the axillary vein receives the venae comitantes of the brachial artery.
• Superior to the pectoralis minor muscle, the axillary vein is joined by the cephalic vein.


Veins of the forearm and hand.