Ulnar Nerve

Description

• General
  • One of the terminal branches of the brachial plexus
  • It is a continuation of the medial cord and contains fibres from spinal roots C8 and T1.
  • It has motor and sensory supply to the forearm and hand.
• Course
  • It runs medial to the axillary artery.
  • The ulnar nerve penetrates the medial fascial septum to enter the posterior compartment of the arm.
  • It runs posterior to the medial humeral epicondyle in the cubital tunnel.
  • It enters the hand via the ulnar canal (Guyon’s canal).
  • It terminates by giving rise to superficial and deep branches.

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Functions

• Muscular innervations
  • Flexor carpi ulnaris
  • Hypothenar muscles
  • Flexor digitorum profundus
  • Medial two lumbricals
  • Adductor pollicis
• Sensory innervations
  • Palmar cutaneous branch innervates: the medial half of the palm.
  • Dorsal cutaneous branch innervates: the medial side of the dorsum of hand.
  • Superficial branch innervates: the anterior aspect of the ulnar 1½ digits (little finger and half of the ring finger).

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Clinical Significance

• Ulnar Nerve Injury

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See Also

• Hand And Wrist Anatomy
• Elbow joint
• Forearm Anatomy

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