Nervus ulnaris

Nervus Ulnaris or the Ulnar Nerve is one of the three main nerves in the human arm. It travels from the neck down into the hand, and can be constricted in several places along the way, causing a variety of symptoms.

Anatomy

The Ulnar Nerve originates from the brachial plexus, carrying fibers from the eighth cervical and first thoracic roots. It travels down the arm, passing posterior to the medial epicondyle of the humerus, through the cubital tunnel (at the elbow) and the Guyon's canal (at the wrist), to innervate (supply nerves to) the muscles of the hand and forearm, and the skin of the hand.

Function

The Ulnar Nerve has both motor and sensory functions. It provides sensation to the little finger and half of the ring finger, and motor innervation to the muscles of the hand and forearm, excluding the thenar muscles and two lateral lumbricals.

Clinical Significance

Damage to the Ulnar Nerve can result in a variety of symptoms, depending on where the nerve is constricted. This condition is known as Ulnar Nerve Entrapment. Symptoms can include numbness or tingling in the ring and little fingers, pain in the forearm, and/or weakness in the hand.

Treatment

Treatment for Ulnar Nerve Entrapment depends on the severity of the symptoms and the location of the constriction. Non-surgical treatments include physical therapy, nonsteroidal anti-inflammatory drugs (NSAIDs), and braces or splints. In severe cases, surgery may be required to relieve the pressure on the nerve.

See Also

• Nervous System
• Peripheral Nervous System
• Brachial Plexus
• Ulnar Nerve Entrapment