Nerve Supply of the Upper Limb

The Brachial Plexus

Learning Outcomesafter this session you should be able to…

• Describe the basic anatomy and course of the brachial plexus

• Describe the distribution of all branches of the plexus

• Describe the course of the major nerves and identify where each is vulnerable to injury

• Identify the dermatomes of the upper limb

• Predict the effects of damage to nerve roots, the plexus and peripheral nerves based on anatomical knowledge

ANATOMY OF THE PLEXUS

Brachial PlexusDrake et al (2005) Gray’s Anatomy for Students (Publ Elsevier)

Brachial plexus in contextRef: Drake et al (2005), Gray’s Anatomy for Students Flash Cards, Elsevier

Course of the brachial plexus

• Trunks– Emerge between anterior & middle scalenes– Palpable between the clavicle and lower part of the

posterior border of SCM

• Divisions– Posterior to clavicle, between clavicle & 1st rib

• Cords– Lie around the axillary artery; initially between 1st ICS

& clavicular ehad of pec major; then between subscapularis & pectoral muscles

– Palpable in the axilla

Supraclavicular branches

• Dorsal scapular n

• Long thoracic n (of Bell)

• N to subclavius

• Suprascapular n

Infraclavicular branches

• Lateral pectoral n• Medial pectoral n• Superior subscapular n• Inferior subscapular n• Thoracodorsal n• Medial cutaneous n of

the arm• Medial cutaneous n of

the forearm

• Axillary n• Musculocutaneous n• Radial n• Ulnar n• Median n

“minor” nerves – know distribution“major” nerves – course & distribution

Dermatomes of the upper limbRef: Gilroy, Mac Pherson & Ross (2008) Atlas of Anatomy

Cutaneous InnervationRef: Gilroy, Mac Pherson & Ross (2008) Atlas of Anatomy

Key Words• Dermatome• Myotome• Cutaneous nerve• Prefixed brachial plexus• Postfixed brachial plexus• Roots• Trunks• Divisions• Cords• Supraclavicular branches • Infraclavicular branches

• Course• Distribution• Carpal tunnel syndrome• Palsy• Paraesthesia• Anaesthesia• Paresis• Paralysis• Erb’s palsy• Klumpke’s palsy