Biceps Brachii

Biceps Brachii

The biceps brachii is a prominent muscle located in the upper arm, playing a crucial role in the movement of the elbow and shoulder joints. It is one of the most well-known muscles due to its visibility and significance in arm flexion.

Anatomy

The biceps brachii is a two-headed muscle, meaning it has two points of origin:

• Short head: Originates from the coracoid process of the scapula.
• Long head: Originates from the supraglenoid tubercle of the scapula.

Both heads converge to form a single muscle belly that inserts into the radial tuberosity of the radius and the bicipital aponeurosis, which blends with the fascia of the forearm.

Function

The primary functions of the biceps brachii include:

• Flexion of the elbow: The biceps brachii is a powerful flexor of the elbow joint.
• Supination of the forearm: It is also a strong supinator, meaning it helps rotate the forearm to turn the palm upwards.
• Assistance in shoulder flexion: The biceps brachii assists in flexing the shoulder joint.

Innervation

The biceps brachii is innervated by the musculocutaneous nerve, which arises from the brachial plexus.

Blood Supply

The blood supply to the biceps brachii is primarily from the brachial artery, with contributions from the anterior circumflex humeral artery.

Clinical Significance

Biceps Tendonitis

Biceps tendonitis is an inflammation of the biceps tendon, often resulting from overuse or repetitive motion. It commonly affects athletes and individuals engaged in activities requiring frequent elbow flexion and supination.

Biceps Rupture

A rupture of the biceps tendon can occur at the shoulder or elbow, leading to a "Popeye" deformity if the tendon retracts. Surgical intervention may be required depending on the severity and functional demands of the patient.

See Also

• Triceps brachii
• Brachialis
• Musculocutaneous nerve

References

• Moore, K. L., Dalley, A. F., & Agur, A. M. R. (2013). Clinically Oriented Anatomy. Lippincott Williams & Wilkins.
• Netter, F. H. (2014). Atlas of Human Anatomy. Elsevier Health Sciences.

External Links

• Biceps Brachii - PubMed
• Biceps Brachii - Anatomy.tv