2. Objective
At the end of this class students should be able to
ā¢ Draw diagram of brachial plexus with all
branches
ā¢ Enumerate the root value of all branches of
brachial plexus
ā¢ Identify lesions of brachial plexus
4. INTRODUCTION
ā¢ Network of nerves
ā¢ Lies in neck and axilla
ā¢ Formed by ventral rami of C5 to T1 (roots)
ā¢ Gives rise to nerves - innervate upper limb
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5. COMPONENT PARTS
ā¢ ROOTS - Five ventral rami (C5-T1)
ā¢ TRUNKS ā Upper, Middle, and Lower
ā¢ DIVISIONS ā Anterior & Posterior from each
trunk, serve - front and back of limb..???
ā¢ CORDS ā Lateral, Medial and Posterior
ā¢ BRANCHES
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6. Location
ā¢ Rootsā Behind scalenus anterior, emerge between
scalene muscles
ā¢ Trunks -cross lower part of posterior triangle of neck
ā¢ Divisions - behind clavicle
ā¢ Cords - arranged around 2nd part of Axillary art in axilla
ā¢ Supraclavicular part - roots and trunks
ā¢ Infraclavicular part ā cord and branches
14. FROM ROOTS
1.Dorsal scapular nerve C5
2.Nerve to subclavius C5, 6
3.Long thoracic nerve C5, 6, 7
ā¢ Unnamed muscular branches from all roots- scaleni / longus colli
ā¢ C5 root of Phrenic nerve
FROM TRUNKS (UPPER)
1.Suprascapular nerve C5, 6
ļ¶No branches arise from Divisions
BRANCHES
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15. Lateral cord
Lateral pectoral C5, 6, 7
Lateral root of median C(5), 6, 7
Musculocutaneous C5, 6, 7
Medial cord
Medial pectoral C8, T1
Medial root of median C8, T1
Medial cutaneous N of forearm C8, T1
Medial cutaneous N of arm C8, T1
Ulnar C(7), 8, T1
Posterior cord
Upper subscapular C5, 6
Thoracodorsal C6, 7,8
Lower suscapular C5, 6
BRACHIAL PLEXUS: NERVES FROM CORDS
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16. DISTRIBUTION OF MAIN NERVES
ā MUSCULOCUTANEOUS
ā¢ Muscles of Anterior Compartment of arm (flexors)
ā MEDIAN
ā¢ Most Flexor muscles of forearm & Intrinsic muscles in hand
ā ULNAR
ā¢ FCU & part of FDP (forearm) and Intrinsic muscles in hand
ā AXILLARY
ā¢ Deltoid & Teres minor
ā RADIAL
ā¢ Innervates all Extensor muscles of arm & forearm
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17. DORSAL SCAPULAR NERVE
ā arise from C 5 roots
posterior aspect
ā Run down deep to levator
scapulae and two
rhomboids.
ā Supply
ā¢ levator scapulae and two
rhomboids
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18. NERVE TO SUBCLAVIUS
ā¢ Small & arises near the junction of C5 and C6 ventral
rami (ERBS POINT)
ā¢ Descends anterior to the trunks of plexus and
Subclavian vessels
ā¢ connected to Phrenic nerve (if it contains fibres of
accessory phrenic nerve.)
ā¢ Supply Subclavius.
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20. LONG THORACIC NERVE
ā¢ Arises from roots C 5,6,7
ā¢ Forms on first digitations of serratus anterior
muscle
ā¢ run vertically downwards just behind the mid
axillary line.
ā¢ Nerve supply
ā¢ C5 ā supply first two digitations,
ā¢ C6 ā next two digitations,
ā¢ C7 ā lowest four digitations.
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22. SUPRASCAPULAR NERVE
ā Derived from upper trunk C5,6 at erbās point
ā Supplies
ā¢ Supraspinatus,
ā¢ Infraspinatus
ā¢ Articular rami to Shoulder and Acromio
clavicular joints.
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23. 1. UPPER SUBSCAPULAR NERVE
ā¢ Smaller than lower.
ā¢ Enters Subscapularis at a high level.
ā¢ Frequently double.
ā¢ Supplies subscapularis
2. LOWER SUBSCAPULAR NERVE
ā¢ Pass deep to sub scapular art.
ā¢ Supplies
ā¢ Subscapularis (lower part)
ā¢ Teres major
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24. THORACODORSAL NERVE
ā Arises between upper and lower Sub scapular
nerves .
ā Accompanies sub scapular artery along
posterior axillary wall.
ā Supplies Latissimus dorsi.
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25. Lesions in Brachial plexus
1. Damage to whole plexus ??
2. Lesion of Long Thoracic N of Bell
3. Lesion of Suprascapular N
4. Upper trunk palsy
5. Lower trunk palsy
6. Cord injuries ā Lateral, Medial , Posterior
7. Lesion of Axillary N
8. Lesion of Musculocutaneous N
9. Variations
10. Brachial plexus block
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26. ā¢ CAUSES
ā¢ Sudden heavy loads on shoulder
ā¢ Carrying heavy loads on shoulder
ā¢ Symptom and sign
ā¢ Winging of scapula
ā¢ prominence of medial border of scapula
ā¢ Loss of pushing and punching actions.
ā¢ Abduction of arm affected.
ā¢ Demonstrated by
ā¢ asking the patient to push against resistance with the forearm
extended at the elbow and flexed to 90Ā° at the shoulder.
Lesion of long thoracic nerve
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28. Upper trunk lesions: ERBāS PALSY
6
7
5
3
4
C 5
C 6
1
2
ERBāS POINT
ā¢ Cause of injury
ā Forceful separation of head from shoulder e.g. during birth
ā fall on shoulder.
ā¢ Nerve roots involved - C5, C6
ā¢ position of limb-
ā Arm hangs by side - Adducted - (no abduction)
ā medially rotated -(no lateral rotation)
ā Extension at elbow.- (no flexion)
ā Forearm is pronated.- (no supination)
ā¢ POLICEMANāS TIP OR WAITER TIP HAND
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31. LOWER TRUNK PALSIES: Klumpkeās palsy
Site of Injury
ā Lower trunk (C 8, T1).
ā Medial Cord involved (ulnar, medial cut N of Arm and forearm)
Cause of injury
ā Birth injury (klumpkeās paralysis)
ā Cervical rib
ā Undue abduction of arm while holding something with hands during fall
from height.
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32. ā¢ Muscle Involved
ā Ulnar N
ā paralysis of Intrinsic muscle of hand, ulnar flexors of wrist
and fingers
ā¢ Symptom and Sign
ā Claw hand (medial two fingers more affected)
ā¢ due to unopposed action of long flexors fingers and
extensors
ā¢ paralysis of all interossei and medial two lumbricals.
ā Sensory loss on ulnar side of hand and forearm.
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