Medial pectoral nerve

Medial Pectoral Nerve

The medial pectoral nerve is a branch of the brachial plexus that innervates the pectoralis major and pectoralis minor muscles. It plays a crucial role in the movement and stabilization of the shoulder joint.

Anatomy

Diagram of the brachial plexus, showing the medial pectoral nerve.

The medial pectoral nerve arises from the medial cord of the brachial plexus, which is derived from the anterior divisions of the lower trunk. It typically contains fibers from the C8 and T1 spinal nerves.

Course

The nerve travels inferiorly and laterally, passing between the axillary artery and vein. It then pierces the pectoralis minor muscle to reach the pectoralis major.

Innervation

The medial pectoral nerve provides motor innervation to the pectoralis minor and the lower part of the pectoralis major. It is responsible for movements such as adduction and medial rotation of the arm.

Function

The primary function of the medial pectoral nerve is to facilitate the movement of the shoulder joint by innervating the pectoral muscles. These muscles are involved in actions such as pushing and lifting.

Clinical Significance

Injury to the medial pectoral nerve can result in weakness or paralysis of the pectoral muscles, affecting shoulder movement. Such injuries may occur due to trauma, surgical procedures, or compression.

Color-coded diagram of the brachial plexus, highlighting the medial pectoral nerve.

Related Structures

The medial pectoral nerve is closely associated with other branches of the brachial plexus, including the lateral pectoral nerve, which also innervates the pectoralis major.

Related Pages

• Brachial plexus
• Pectoralis major
• Pectoralis minor
• Lateral pectoral nerve

Nerves of the left upper extremity, including the medial pectoral nerve.

See Also

• Nerve injury
• Shoulder joint
• Muscle innervation