Anterior humeral circumflex artery

Medically Reviewed by Anatomy Team

Last updated on January 24, 2025

The anterior humeral circumflex artery is a smaller branch of the axillary artery, typically arising from its third part. This artery plays a key role in supplying blood to the shoulder region, particularly to the humeral head and parts of the deltoid muscle. It is part of a vascular network in the shoulder that ensures proper blood supply to the surrounding muscles and joints.

Location

The anterior humeral circumflex artery originates from the third part of the axillary artery, near the shoulder. It travels laterally, running horizontally along the anterior surface of the humerus, just below the joint capsule of the shoulder. The artery passes deep to the biceps brachii and coracobrachialis muscles, circling around the humerus toward the lateral side. It typically anastomoses with the posterior humeral circumflex artery around the humeral head, forming part of the blood supply to the upper end of the humerus, the shoulder joint, and nearby muscles.

Anatomy

The anterior humeral circumflex artery is a vital vessel that provides blood supply to the shoulder region, including the humeral head and surrounding muscles.^[1] Below is a detailed description of its anatomy, including its origin, course, branches, and relationship with surrounding structures.

Origin

The anterior humeral circumflex artery originates from the third part of the axillary artery, a major artery that supplies the upper limb. The axillary artery becomes the brachial artery as it passes down the arm, but before that transition, it gives off several important branches, including the anterior humeral circumflex artery. The artery arises near the shoulder joint, often alongside the larger posterior humeral circumflex artery.

Course

The anterior humeral circumflex artery follows a lateral and anterior path around the humerus, traveling just below the shoulder joint. Its course can be divided into a few key segments:

Proximal Course

After branching from the axillary artery, the anterior humeral circumflex artery travels laterally across the anterior aspect of the shoulder. It passes deep to the coracobrachialis and short head of the biceps brachii muscles.^[2] As it courses along the anterior aspect of the humeral head, it provides small branches to nearby structures, including parts of the joint capsule and muscles.

Relationship to Shoulder Joint: The artery runs in close proximity to the glenohumeral joint, which is the articulation between the head of the humerus and the glenoid cavity of the scapula. This relationship is important for delivering blood to the joint structures.

Circumferential Path

The artery continues its circumferential path, running horizontally around the anterior surface of the humerus. As it approaches the lateral side of the humerus, it typically moves deeper, traveling near the anatomical neck of the humerus.

Biceps and Coracobrachialis: In this region, the artery remains deep to the biceps brachii and coracobrachialis muscles, providing branches to these muscles as well as the bone and joint.

Branches

The anterior humeral circumflex artery gives off several small branches that supply the muscles and structures around the shoulder.^[3] While it is smaller compared to the posterior humeral circumflex artery, it still plays a key role in the vascular network of the shoulder.

Deltoid and Muscular Branches

The anterior humeral circumflex artery supplies small muscular branches to the deltoid muscle. This muscle is involved in shoulder movements such as abduction, and the blood supply provided by the artery ensures that it has the oxygen and nutrients necessary for function.

Biceps Brachii and Coracobrachialis Branches: The artery also provides small branches to the biceps brachii and coracobrachialis muscles, two key muscles involved in flexion of the elbow and shoulder.

Articular Branches

The anterior humeral circumflex artery gives off small articular branches that supply the glenohumeral joint. These branches contribute to the vascularization of the joint capsule, synovium, and other structures in the shoulder joint, playing a role in maintaining joint health and function.

Ascending Branch

One of the most important branches of the anterior humeral circumflex artery is the ascending branch, which runs superiorly toward the humeral head. This branch helps supply the head of the humerus, contributing to the blood supply of this important structure.

Anastomoses

The anterior humeral circumflex artery forms an important anastomosis with the posterior humeral circumflex artery, another branch of the axillary artery. This anastomosis occurs around the head of the humerus, creating a vascular network that ensures adequate blood supply to the humeral head and shoulder joint, even if one of the arteries is compromised.

Anastomosis with Posterior Humeral Circumflex Artery: The anastomosis between the anterior and posterior humeral circumflex arteries is critical for maintaining a robust blood supply to the proximal humerus, the joint capsule, and the deltoid muscle. The larger posterior humeral circumflex artery contributes most of the blood supply, but the anterior humeral circumflex artery plays a supporting role in this vascular network.

Termination

The anterior humeral circumflex artery continues to course around the humerus and eventually terminates by forming the anastomosis with the posterior humeral circumflex artery. This termination allows the blood from both arteries to circulate around the humeral head, ensuring that this critical structure receives an adequate blood supply from multiple sources.

Relationship to Surrounding Structures

The anterior humeral circumflex artery has several important relationships with the surrounding anatomical structures of the shoulder:

Axillary Nerve: While the anterior humeral circumflex artery does not travel directly with the axillary nerve, both are in close proximity as the nerve passes through the quadrangular space along with the posterior humeral circumflex artery. Their nearby courses highlight the interconnected nature of the neurovascular structures in the shoulder.
Biceps Tendon: The artery passes near the long head of the biceps brachii tendon, which runs through the bicipital groove of the humerus. This relationship is important for the blood supply to the biceps tendon and nearby structures.
Coracobrachialis Muscle: The artery runs deep to the coracobrachialis muscle for part of its course, providing blood to this muscle as well as the biceps brachii. Its proximity to these muscles helps sustain their function in shoulder flexion and stability.

Variations

The anatomy of the anterior humeral circumflex artery can vary between individuals. Some common variations include:

Size Variation: The anterior humeral circumflex artery is typically smaller than the posterior humeral circumflex artery, but in some individuals, the size of the two arteries may be more equal.
Origin Variations: In some cases, the artery may arise higher or lower than usual on the axillary artery, and in rare cases, it may share a common trunk with the posterior humeral circumflex artery.

Function

The anterior humeral circumflex artery plays an important role in the vascular supply of the shoulder region. Although it is typically smaller than the posterior humeral circumflex artery, it contributes to the blood flow of key structures in the upper arm and shoulder, including muscles, joints, and bones.^[4] Below is a detailed description of the functions of the anterior humeral circumflex artery.

Blood Supply to the Humeral Head

One of the primary functions of the anterior humeral circumflex artery is to provide blood to the humeral head, the proximal part of the humerus that articulates with the glenoid cavity of the scapula to form the shoulder joint.

Nourishment of the Humeral Head: Through its ascending branch, the anterior humeral circumflex artery delivers oxygenated blood to the humeral head, ensuring the health and vitality of the bone tissue. This is crucial for maintaining the structural integrity of the bone, which is essential for shoulder joint mobility and strength.
Anastomosis with Posterior Humeral Circumflex Artery: The artery forms an anastomosis with the posterior humeral circumflex artery around the humeral head. This connection ensures that even if one artery is compromised, the other can still supply blood to this vital area, contributing to a robust collateral blood supply.

Blood Supply to the Shoulder Joint

The anterior humeral circumflex artery plays a key role in supplying blood to the glenohumeral joint, which is the ball-and-socket joint of the shoulder.

Articular Branches: The artery provides small articular branches that supply the joint capsule, synovium, and surrounding ligaments.^[5] These structures require a consistent blood supply to maintain their health, as they support smooth movement within the shoulder joint and help protect the joint from wear and tear.
Joint Health: By delivering oxygenated blood to these soft tissues, the artery contributes to the overall health of the shoulder joint, enabling it to function effectively during movement and preventing the degeneration of tissues.

Blood Supply to the Deltoid Muscle

The deltoid muscle, which covers the shoulder and is responsible for arm abduction and other movements, receives part of its blood supply from the anterior humeral circumflex artery.

Deltoid Branches: The artery sends out small muscular branches to the deltoid muscle, especially the anterior fibers of the deltoid, which are involved in arm flexion and internal rotation. This blood supply ensures that the deltoid muscle has the necessary oxygen and nutrients for contraction and recovery after activity.
Sustaining Muscle Function: By supplying the deltoid muscle with blood, the anterior humeral circumflex artery supports its role in arm movements such as lifting and rotating the shoulder, which are critical for a wide range of physical activities.

Blood Supply to the Biceps Brachii and Coracobrachialis Muscles

The anterior humeral circumflex artery also provides blood to the biceps brachii and coracobrachialis muscles, which are essential for flexion of the elbow and shoulder.

Biceps Brachii: The artery supplies small branches to the short head of the biceps brachii, which assists in flexing the elbow and supinating the forearm.^[6] The anterior humeral circumflex artery ensures that the biceps muscle has adequate blood flow to function effectively during these movements.
Coracobrachialis: This muscle, which assists in flexing and adducting the shoulder, also receives blood from the anterior humeral circumflex artery. The artery helps maintain the strength and function of the coracobrachialis during shoulder movements.

Collateral Circulation in the Shoulder

The anterior humeral circumflex artery contributes to the collateral circulation in the shoulder region, particularly through its anastomosis with the posterior humeral circumflex artery. This anastomotic network ensures that blood flow to the shoulder is maintained even if one of the arteries is obstructed or compromised.

Anastomosis with Posterior Humeral Circumflex Artery: The connection between the anterior and posterior humeral circumflex arteries allows for continuous blood supply to the humeral head, shoulder joint, and surrounding muscles. This is important for maintaining adequate circulation during movements that might compress one of the vessels or during injury.
Redundant Blood Supply: The collateral circulation created by these anastomoses helps prevent ischemia (lack of blood supply) in the shoulder region. It ensures that tissues receive a steady supply of oxygen and nutrients, even if there are blockages in one of the arteries.

Oxygen and Nutrient Delivery

Like all arteries, the anterior humeral circumflex artery’s primary function is to deliver oxygen and nutrients to the tissues it supplies. This function is critical for the health, maintenance, and repair of muscles, bones, and soft tissues in the shoulder.

Tissue Repair and Recovery: The artery ensures that the muscles and tissues in the shoulder, including the deltoid, biceps, and coracobrachialis, receive the necessary oxygen and nutrients for recovery after physical activity or injury.^[7] This is essential for muscle growth, strength maintenance, and tissue healing.
Bone Health: By delivering oxygen and nutrients to the humeral head and surrounding bone tissue, the artery helps maintain bone density and strength, ensuring that the humerus can withstand the forces generated during shoulder movement.

Support for Shoulder Movement and Stability

The anterior humeral circumflex artery plays a vital role in supporting shoulder movement and stability by supplying the muscles and joints that contribute to these functions.

Arm Flexion and Abduction: By delivering blood to the deltoid and biceps brachii, the artery supports movements such as arm flexion (lifting the arm forward) and abduction (lifting the arm away from the body).^[8] These movements are essential for everyday tasks such as lifting, reaching, and pushing.
Shoulder Joint Stability: The artery’s blood supply to the joint capsule and ligaments of the glenohumeral joint helps maintain the stability of the shoulder during motion. This is especially important in preventing dislocations or other injuries to the joint.

Clinical Significance

The anterior humeral circumflex artery plays a crucial role in supplying blood to the humeral head, shoulder joint, and surrounding muscles. Though it is smaller than the posterior humeral circumflex artery, its clinical significance lies in its contribution to the vascularization of important structures in the shoulder.

Fractures of the Humeral Head: Injuries such as fractures of the humeral head or neck can damage the anterior humeral circumflex artery, potentially compromising the blood supply to the head of the humerus. This can lead to avascular necrosis (death of bone tissue due to lack of blood), which is a serious complication requiring prompt medical intervention.
Surgical Procedures: During shoulder surgeries, such as joint replacements or repairs of the rotator cuff, the anterior humeral circumflex artery must be preserved to ensure adequate blood flow to the humeral head and surrounding tissues. Damage to this artery during surgery can result in poor healing or joint dysfunction.
Shoulder Injuries: Dislocations or trauma to the shoulder region can affect the artery’s ability to supply blood to the shoulder joint and muscles. Understanding its anatomy is crucial in diagnosing and managing vascular injuries in shoulder trauma.

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