Subclavian, Axillary, Brachial, Radial, and Ulnar Arteries

Subclavian Artery

The subclavian artery is divided into three portions: pre-scalenic, intra-scalenic, and post-scalenic. It originates several branches:

• Vertebral Artery: Both vertebral arteries join to form the basilar artery, which contributes to the posterior cerebral circulation.
• Internal Thoracic Artery: Gives off mediastinal branches, thymic branches, bronchial branches, the pericardiacophrenic artery, sternal branches, perforating branches, lateral costal branches, and anterior intercostal branches. The internal thoracic artery then divides into the musculophrenic artery and the superior epigastric artery.

Thyrocervical Trunk

The thyrocervical trunk gives rise to:

• Inferior Thyroid Artery: Which further branches into the inferior laryngeal artery, ascending cervical artery, thyroid branches, and twigs to the pharynx, esophagus, and trachea.
• Transverse Cervical Artery
• Suprascapular Artery

Costocervical Trunk

The costocervical trunk splits into:

• Deep Cervical Artery
• Supreme Intercostal Artery

Axillary Artery

The axillary artery begins at the lateral border of the first rib as a continuation of the subclavian artery and ends at the inferior border of the teres major muscle. Its branches include:

• Subscapular Artery (which branches into the thoracodorsal artery and circumflex scapular artery)
• Superior Thoracic Artery
• Thoracoacromial Artery
• Lateral Thoracic Artery
• Anterior Humeral Circumflex Artery
• Posterior Humeral Circumflex Artery

Brachial Artery

The brachial artery traverses the anteromedial aspect of the arm and terminates in the ulnar fossa, where it bifurcates into the radial and ulnar arteries. It is superficial throughout its course. Anteriorly, it is covered by the biceps brachii muscle. Posteriorly, it lies against the triceps brachii and coracobrachialis muscles. Laterally, it is related to the coracobrachialis muscle superiorly and the biceps and brachialis muscles inferiorly. Medially, it is in contact with the brachial fascia and the integument.

Branches:

• Profunda Brachii Artery (travels posterior to the humerus and divides into the middle collateral artery and radial collateral artery).
• Superior Ulnar Collateral Artery (gives rise to the ulnar recurrent artery).
• Inferior Ulnar Collateral Artery (joins the medial collateral circulation in the olecranon fossa; it gives off an anterior and a posterior branch).

Radial Artery

The radial artery originates in the ulnar fossa and descends along the lateral border of the forearm to the wrist, contributing to the formation of the deep palmar arch. It is covered in its superior two-thirds by the brachioradialis muscle. The radial nerve lies close to the artery in the lower third of the forearm, where the radial pulse can be palpated.

Branches:

• Radial Recurrent Artery
• Palmar Carpal Branch
• Superficial Palmar Branch
• Dorsal Carpal Branch (gives rise to three dorsal metacarpal arteries)
• Princeps Pollicis Artery
• Artery of the Medial Border

Ulnar Artery

Branches:

• Ulnar Recurrent Artery
• Common Interosseous Artery (arises in the medial aspect of the ulnar fossa and divides into anterior and posterior interosseous arteries; the posterior interosseous artery gives off the interosseous recurrent artery, which is accompanied by the median nerve).
• Palmar Carpal Branch
• Dorsal Carpal Branch
• Deep Palmar Branch (joins the radial artery to form the deep palmar arch)
• Superficial Palmar Arch (gives rise to three common palmar digital arteries and three proper palmar digital arteries).