Superficial Subcutaneous Veins
Superficial veins are located within the subcutaneous tissue and do not have direct companion arteries. The two primary collectors of this system are:
- Cephalic vein (v. cephalica). Ascends along the lateral margin of the forearm. In the cubital region, it may receive a variable accessory cephalic vein (v. cephalica accessoria). It then continues up the arm, courses deeply inferior to the clavicle, perforates the clavipectoral fascia (fascia clavipectoralis), and drains into the axillary vein. Along its path, it receives the thoracoacromial vein.
- Basilic vein (v. basilica). Continues from the 4th dorsal metacarpal vein. Ascending along the dorsal aspect of the forearm, it shifts to the palmar surface and courses along the medial margin. In the cubital region, its caliber increases significantly after receiving the median cubital vein. In the arm, it enters the medial bicipital groove (sulcus bicipitalis medialis), perforates the brachial fascia at the junction of the lower and middle thirds, and empties into the brachial veins (vv. brachiales). Occasionally, it may extend directly into the axilla.
Between these two major veins on the anterior forearm, the inconstant median antebrachial vein (v. mediana antebrachii) is frequently found. In the upper third of the forearm, it either merges with the median cubital vein or bifurcates into two trunks—the v. cephalica antebrachii and v. basilica antebrachii—which drain into the respective main superficial veins.
Deep Veins and Venous Arches
Deep veins (vv. profundae membri superioris) drain blood from deep structures: bones, joints, and muscles. A characteristic feature is that they run in pairs (vv. comitantes), flanking a single corresponding artery.
Veins of the Hand:
- Superficial palmar venous arch (arcus venosus palmaris superficialis) — poorly developed, located near the bases of the fingers, receiving the palmar digital veins (vv. digitales palmares).
- Deep palmar venous arch (arcus venosus palmaris profundus) — consists of paired anastomosing veins accompanying the deep arterial arch. It receives the palmar metacarpal veins, which drain blood from the interosseous and lumbrical muscles. In the first intermetacarpal space, the deep arch forms an important anastomosis with the 1st dorsal metacarpal vein.
Veins of the Forearm and Arm: From the hand, the deep veins ascend into the forearm, forming the radial (vv. radiales) and ulnar (vv. ulnares) veins, which course on either side of their respective arteries. In the cubital fossa, they merge to form two brachial veins (vv. brachiales). The brachial veins accompany the brachial artery, receive muscular tributaries, and unite into a single large trunk upon entering the axilla.
Axillary Vein as the Main Collector
Axillary vein (v. axillaris) is the main vessel receiving blood from both the deep and superficial systems of the upper extremity.
It lies within the axillary fossa anterior to the axillary artery. The vein extends from the lower border of the pectoralis major muscle (m. pectoralis major) to the 1st rib, where it continues as the subclavian vein (v. subclavia).
The axillary vein receives the cephalic vein (v. cephalica) as well as deep veins accompanying the branches of the axillary artery:
- Subscapular vein (v. subscapularis).
- Circumflex humeral veins (anterior and posterior).
- Circumflex scapular vein (v. circumflexa scapulae).
- Lateral thoracic vein (v. thoracica lateralis).
- Thoracoepigastric vein (v. thoracoepigastrica).
At the root of the neck, the subclavian vein joins the internal jugular vein (v. jugularis interna) to form the large brachiocephalic vein (v. brachiocephalica).