Brachial Artery

Introduction

Introduction to the Brachial Artery

The brachial artery is the main arterial supply of the arm (brachium) and is the continuation of the axillary artery. It begins at the lower border of the teres major muscle and ends in the cubital fossa opposite the neck of the radius, where it divides into the radial and ulnar arteries. The brachial artery runs medially in the anterior compartment of the arm, accompanied by venae comitantes and the median nerve. It gives off important branches including the profunda brachii (deep artery of the arm), nutrient artery to the humerus, and several collateral vessels. Clinically, it is the vessel most commonly used for measuring blood pressure (via auscultation over the cubital fossa) and for palpation of the brachial pulse (medial to the biceps tendon).

Study

Course and Relations of the Brachial Artery

The brachial artery begins at the lower border of teres major and ends 1 cm distal to the elbow crease (cubital fossa). In the proximal arm, it lies medial to the humerus, superficial to the triceps and coracobrachialis. The median nerve is initially lateral to the artery, then crosses anteriorly (often at mid-arm) to lie medial. The ulnar nerve lies medial to the artery in the proximal third, then pierces the medial intermuscular septum to enter the posterior compartment. The basilic vein (superficial) perforates the deep fascia near mid-arm to join the brachial venae comitantes and form the axillary vein. The bicipital aponeurosis (lacertus fibrosus) covers the artery in the cubital fossa.

Branches of the Brachial Artery

1. Profunda brachii (deep brachial artery): Largest branch, arises just distal to teres major. Runs with radial nerve in radial groove, divides into middle collateral (anastomoses with interosseous recurrent) and radial collateral (anastomoses with radial recurrent). Supplies posterior compartment (triceps). 2. Superior ulnar collateral artery: Arises near mid-arm, runs with ulnar nerve (pierces medial intermuscular septum), anastomoses with posterior ulnar recurrent. 3. Inferior ulnar collateral artery: Arises just above elbow, runs anterior to medial epicondyle, anastomoses with anterior ulnar recurrent. 4. Nutrient artery to humerus: Usually from profunda brachii; enters nutrient foramen. 5. Muscular branches: To coracobrachialis, biceps, brachialis. 6. Terminal branches: Radial and ulnar arteries at cubital fossa.

Anastomoses Around the Elbow

The brachial artery participates in the rich periarticular anastomosis of the elbow, ensuring collateral circulation if the artery is occluded at the cubital fossa. Key connections: - Radial collateral (from profunda brachii) ↔ radial recurrent (from radial artery) - Middle collateral (from profunda brachii) ↔ interosseous recurrent (from posterior interosseous) - Superior ulnar collateral ↔ posterior ulnar recurrent (from ulnar artery) - Inferior ulnar collateral ↔ anterior ulnar recurrent (from ulnar artery)

Clinical Relevance

Brachial pulse: Palpated medially to biceps tendon in cubital fossa. Used for blood pressure measurement with stethoscope over brachial artery. Brachial artery injury: Most common in supracondylar humeral fractures (children) – can lead to compartment syndrome, Volkmann's ischemic contracture. Also iatrogenic from cardiac catheterization (transradial or transbrachial approach) or arteriovenous fistula creation for hemodialysis. Brachial artery aneurysm: Rare; may cause distal embolization. Variations: High bifurcation (radial and ulnar arteries arise in axilla) occurs in ~20%. Superficial brachial artery (superficial to median nerve) may be present.

Summary

Key Takeaways – Brachial Artery

Origin: Continuation of axillary artery at lower border of teres major. Termination: Divides into radial and ulnar arteries at cubital fossa (level of radial neck). Branches: Profunda brachii, superior and inferior ulnar collaterals, nutrient, muscular. Relations: Median nerve (crosses from lateral to medial); ulnar nerve (medial then leaves); basilic vein. Clinical: Palpable pulse medial to biceps tendon; injury risk in supracondylar fracture; anastomoses allow collateral flow.