Brachial Plexus Diagram

Understand the brachial plexus with our detailed diagram. Ideal for health professionals, patients, and medical students. Download our free template now.

By Nate Lacson on Aug 2, 2025.

Fact Checked by Ericka Pingol.

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What is the brachial plexus?

The brachial plexus is a complex network of nerves that originates from the spinal cord in the neck and travels down the upper limb. It is responsible for the motor and sensory innervation of the upper limb, including the shoulder, arm, forearm, and hand. The brachial plexus consists of five parts: roots, trunks, divisions, cords, and branches.

Here's a more detailed breakdown:

Roots: The anterior rami of the C5, C6, C7, C8, and T1 spinal nerves form the roots of the brachial plexus.
Trunks: Each nerve root combines to form three trunks:
- Upper trunk (superior trunk): Formed by the union of the C5 and C6 roots.
- Middle trunk: Continuation of the C7 root.
- Lower trunk: Formed by the union of the C8 and T1 roots.
Divisions: Each trunk splits into an anterior and a posterior division.
Cords: The divisions form three cords:
- Lateral cord: Formed by the anterior divisions of the upper and middle trunks.
- Posterior cord: Formed by the posterior divisions of all three trunks.
- Medial cord: Formed by the anterior division of the lower trunk.
Branches: The cords give rise to five major nerves:
- Musculocutaneous nerve: Innervates the brachialis, biceps brachii, and coracobrachialis muscles. Provides sensation to the lateral half of the anterior forearm.
- Axillary nerve: Innervates the teres minor and deltoid muscles. Provides sensation to the inferior region of the deltoid.
- Median nerve: Innervates most of the flexor muscles in the forearm and the thenar muscles. Provides sensation to the lateral part of the palm and the lateral three and a half fingers on the palmar surface.
- Radial nerve: Innervates the triceps brachii and the posterior compartment of the forearm. Provides sensation to the posterior aspect of the arm and forearm.
- Ulnar nerve: Innervates the muscles of the hand (apart from the thenar muscles and two lateral lumbricals), flexor carpi ulnaris, and the medial half of flexor digitorum profundus. Provides sensation to the medial one and a half fingers.

In addition to these major branches, the brachial plexus also has several minor branches that provide innervation to other muscles and skin areas.

Roots: Dorsal scapular nerve, long thoracic nerve
Trunks: suprascapular nerve, subclavian nerve (nerve to subclavius)
Lateral cord: Lateral pectoral nerve
Medial cord: Medial pectoral nerve, medial antebrachial cutaneous nerve (also known as the medial cutaneous nerve of the forearm), medial brachial cutaneous nerve (also known as the medial cutaneous nerve of the arm or the lesser internal cutaneous nerve)
Posterior cord: Superior subscapular nerve, thoracodorsal nerve, inferior subscapular nerve

Brachial Plexus Diagram Template

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What can impair the brachial plexus' function?

The brachial plexus can be impaired by various factors, including physical trauma, repetitive stress, and medical conditions. These impairments can lead to partial or complete loss of function in the affected arm, causing significant discomfort and disability. Traumatic brachial plexus injuries, such as accidents, car crashes, falls, and sports injuries, can cause severe damage resulting in nerve damage. Additionally, birth injuries during difficult deliveries can sometimes stretch or tear the brachial plexus in newborns, leading to conditions like Erb's palsy.

Repetitive stress from overuse injuries and occupational hazards can also impair the brachial plexus. Repetitive movements, especially those involving heavy lifting or prolonged use of the arms, can compress or irritate the brachial plexus nerves. Jobs that require constant overhead work or heavy physical labor increase the risk of brachial plexus injuries.

Medical conditions such as tumors, inflammatory conditions, and complications from radiation therapy can also impact the brachial plexus. Tumors in the neck or shoulder region can compress the brachial plexus, leading to nerve impairment. Inflammatory conditions like brachial neuritis, which causes sudden and severe shoulder and arm pain followed by weakness, also affect the brachial plexus. Additionally, radiation treatment for cancers in the neck and chest area can sometimes damage the brachial plexus.

What problems can brachial plexus injuries cause?

Brachial plexus injury can lead to a range of short-term and long-term problems, depending on the severity and location of the nerve injuries. Because the posterior, medial, and lateral cords run together with the axillary artery, injuries can result in vascular and sensorimotor issues.

In the short term, patients may experience immediate pain, tingling, or burning sensations in the shoulder, arm, or hand, along with temporary weakness or inability to use certain muscles in the affected arm.

Long-term problems include chronic pain, persistent discomfort that can be debilitating and affect the quality of life. Muscle atrophy, or the wasting away of muscles due to lack of use or nerve stimulation, can occur. Severe injuries can lead to long-term or permanent disability, resulting in loss of function in the affected arm, limiting daily activities and work capabilities. Additionally, contractures, which are abnormal, permanent shortening of muscles or tendons around joints, can lead to deformities and restricted movement. Addressing brachial plexus injuries promptly and appropriately is crucial for minimizing these complications and improving patient outcomes.

What is a Brachial Plexus Diagram?

A Brachial Plexus Diagram is a detailed visual representation of the network of nerves that originate from the spinal cord in the neck and extend through the armpit to innervate the arm. This diagram includes the roots, trunks, divisions, cords, and branches of the brachial plexus, illustrating their complex interconnections and functions. It highlights the major nerves such as the musculocutaneous, axillary, median, radial, and ulnar nerves, along with the minor branches.

Carepatron’s printable and customizable brachial plexus diagram template is an excellent educational tool for healthcare professionals, students, and patients. It provides a clear and concise visual aid for understanding the anatomy and function of the brachial plexus. Additionally, the template includes a section for adding notes, allowing users to personalize the diagram with relevant information or observations, enhancing its utility in both clinical and educational settings.

Common treatments for brachial plexus injuries

Treatment for brachial plexus injuries varies depending on the severity and type of injury. Here are some common treatment options:

Physical and occupational therapy: Regular exercises and therapy sessions can help maintain muscle strength, improve range of motion, and provide strategies for performing daily activities, aiding recovery and preventing further complications.
Medications: Pain relievers and anti-inflammatory drugs can help manage pain and reduce inflammation associated with brachial plexus injuries.
Surgical intervention: In severe cases, surgery may be necessary to repair damaged nerves. Procedures such as nerve grafts, nerve transfers, or muscle transfers can restore function and alleviate symptoms.
Electrical stimulation: This technique uses electrical impulses to stimulate nerves and muscles, promoting healing and improving function in the affected area.
Orthotic devices: Splints or braces can support the affected limb, prevent further injury, and aid in the recovery process.