Presented BY Syed Irshad Murtaza The Aga Khan University Hospital Karachi Pak. Neurophysiology Dept.

1. Anatomy Of Ulnar Nerve
BY: SYED IRSHAD MURTAZA
TRAINEE TECH
NEUROPHYSIOLOGY
AKUH
KARACHI
Date: 30-05-2012

2. Introduction
• Ulnar nerve is on of the major terminal Branches
of Brachial Plexus. It is the continuation of medial
cord of brachial plexus which arises from the
anterior Division of the lower Trunk.
• Root Value:
• The fibers of ulnar nerve arise from the eight
cervical and first thorasic nerve, so the root value
of ulnar nerve is C8 and T1. These (C8,T1)
coordinate to form the lower trunk of brachial
plexus.

3. Brachial Plexus

4. Continuation of Ulnar Nerve
• Course From Cord to Axilla.
• The Ulnar nerve runs between the Axillary artery
and vein in the axilla.
• Course from Axilla to Arm
• From the axilla it enters in the arm and stays
between the brachial artery and vein.

5. .

6. • Course from Arm to Elbow
• The nerve runs inferior and posterior medial
aspect of humerus bone till it enters the
cubital tunnel.
• In the arm throughout the course the nerve
runs superficially and innervates no any
muscle.

8. Cont’d
Course from Elbow to Forearm
• At the elbow the ulnar nerve lies in a groove
(Retrocondylar groove) which is formed by
medial epicondyle humerus and olecranon
process of ulna, referred as "funny bone".
• The ulnar nerve is trapped between the bone
and the overlying skin at this point.
It enters the forearm through the aponeurotic
arcade (Cubital Tunnel).

10. Supplies of Ulnar Nerve In Forearm
The ulnar nerve enters the anterior (flexor)
compartment of the forearm through the two
heads of flexor Carpi ulnaris and runs alongside
the ulna bone.
There it innervates the Flexor Carpi Ulnaris (FCU)
muscle & medial half of Flexor Digitorum
Profundus III & IV (FDP) muscle.
• No further muscle is supplied by the ulnar nerve
in the medial forearm until it enters the wrist
through guyon canal.

11. • G

12. Course from forearm to wrist
Dorsal Cutaneous Innervations of the Ulnar Nerve
In the forearm it runs distally on the ulnar artery, and about
five to eight centimeters proximal to the wrist , the dorsal
ulnar cutaneous sensory branch exits to supply sensation to
the dorsal medial hand and the dorsal little finger as far
distally as the nail & the 4 digit.
Palmar Cutaneous Innervations of the Ulnar Nerve
• At that level of the ulnar styloid the Palmer Cutaneous
sensory branch originates to supply sensation to the
proximal medial palm.

13. Dorsal cutaneous branch

14. Palmar cutaneous branch

15. At the wrist, the ulnar nerve and artery lie in a
canal formed by the pisiform bone medially and
the hook of hamate laterally (Guyon’s canal).
• In this region the nerve divides into two
superficial and deep branches.
• The Superficial Branch
• The Deep Motor Branch

16. 1. The superficial branch is generally considered
a sensory branch which supplies to distal
palm, fifth and half of the fourth digit.
It also supplies palmaris brevis, a thin muscle
beneath the skin which cannot be studied
electromyographically.
The deep branch gives off motor innervation to
the hand muscles. .
• After it travels down the ulna, the ulnar nerve
enters the palm of the hand. The ulnar nerve
and artery pass superficial to the flexor
retinaculum via the ulnar canal.

17. Ulnar Innervated Muscles
• Forearm:
• Flexor Carpi Ulnaris (C7, C8, T1)
• Flexor Digitorum Profundus III & IV (C7, C8)
• Thenar:
• Hypothenar Muscles (C8, T1)
• Adductor Pollicis (C8, T1)
• Flexor Pollicis Brevis (C8, T1)
• Fingers:
• Palmer Interosseous (C8, T1)
• Dorsal Interosseous (C8, T1)
• III & IV Lumbricles (C8, T1)
• Digiti Minimi:
• Abductor Digiti Minimi (Quinti) (C8, T1)
• Opponens Dgiti Minimi (C8-T1)
• Flexor Digiti Minimi. : ( C8-T1)

18. Wrist to (Medial) Hand
• http://www.acnr.co.uk/pdfs/volume3issue2/v
3i2anatomy.pdf
• http://www.wheelessonline.com/ortho/ulnar
_nerve

20. • Anatomy of the ulnar nerve at the elbow, the branches are
the
• dorsal ulnar cutaneous sensory (blue), the palmar
cutaneous sensory
• (yellow), hypothenar motor (green) and the digital sensory
(red), the
• trunk of the nerve in the hand continues as the deep
palmar motor
• branch.

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