2. ANATOMY
A network of nerves starting from 5 nerve
roots in upper spine & ending in nerves that
control movement & sensation in the upper
limb.
3. ANATOMY contd…
Located where neck joins shoulder behind
clavicle & between spine & upper arm just
distal to axilla.
5 roots ant.primary rami after giving
segmental supply to prevertebral muscles
&scalene muscles.
7. ROOTS
THE ORIGIN NERVES ARE THE ANT.
PRIMARY RAMI OF5th TO 8th CERVICAL
VERTEBRAE AND T1.
ROOTS EMERGE FROM THE
TRANSVERSE PROCESSES OF
CERVICAL VERTEBRAE IMMED. POST. TO
VERTEBRAL ARTERY
T1:VULNERABLE IN FRACTURE AND
DISLOCATION OF FIRST RIB
8. NERVES FROM ROOTS .
DORSAL SCAPULAR N. C5
ARISES FROM C5 JUST LAT. TO LONG
THORACIC
TRAV. POST TO Plx
INNERVATES LEV.SCAPULAE, RHOMBOIDES
11. ROOTS contd…
LONG THORACIC N. OF BELL
C567
IMMED. AFTER THEY ORIG. FROM
INTERVERTEBRAL FORAMEN
ALSO PIERCES S.MED. AS IT PASSES
POST TO Plx
12.
13. TRUNKS
IN THE POST. TRIANGLE OF NECK
C56: UPPER/SUPERIOR TRUNK
C7; MIDDLE TRUNK
C8 T1: LOWER/INFERIOR TRUNK
TRUNKS LIE IN FRONT OF ONE
ANOTHER
RELATION b/w C5 AND PHRENIC NERVE
14.
15. NERVES FROM TRUNKS
SUPRASCAPULAR N. C5,6
SENSORY TO SHOULDER JT.
MOTOR TO SUPRASPINATUS AND
INFRASPINATUS
N.TO SUBCLAVIUS C5,6
16. DIVISONS
LIE DEEP TO CLAVICLE
POSTERIOR DIV. OF UPPER AND MIDDLE
TRUNK LARGER
10% OF CASES NO POST. DIVISON OF
LOWER TRUNK
17. CORDS
NAMED LAT. ,POST. AND MEDIAL ACC.
TO RELATION WITH AXILLARY ARTERY
LATERAL CORD: ANT. DIV OF UPPER &
MIDDLE TRUNK
MEDIAL CORD: ANT. DIV. OF LOWER
TRUNK
POSTERIOR CORD:POST./DORSAL
DIVISONS OF ALL 3 TRUNKS
18. FROM LAT.CORD
Lateral pectoral nerve- c5,c6,c7
Pierce clavipectoral fascia.
Communicate with medial pectoral across front
of 1st part of axillary art.
Br. To P.major & P.minor
No cut. Br.
19. FROM LAT. CORD contd…
Musculocutaneous nr.-c5,c6,c7
To biceps & brachialis.
Becomes lateral cut. Nr. Of forearm.
Lateral root of median nr.-c5,c6,c7
Continuation of lat.cord
20. FROM MEDIAL CORD
Medial pectoral nr.- behind 1st part of ax.art
Perforates p.minor
No cut.br.
Medial root of median nr-. Crosses ax. Art to join lat root.
Medial cut.nr. Of arm – smallest & most medial.
Medial cut. Nr. Of forearm –
Large nr.
Runs down bet ax.art & ax. Vein in front of ulnar nr.
Ulnar nr.- largest br. C7 C8 T1
To most of the hand muscles.
21. FROM POST CORD contd…
Radial nr. – c5,c6,c7,c8,T1
Cont.of post cord
Largest in the whole plexus
Gives post cut nr. Of forearm.
22. FROM POST.CORD
Upper subscapular- c5,c6
Small nr.
Enters upper part of subscapularis.
Thoracodorsal – c6,c7,c8
nr.to lat. Dorsi.
A large nerve.
Runs down post.ax. Wall.
23. FROM POST CORD contd…
Lower subscapular –c5,c6
To lower part of subscapularis
Ends in teres major.
Axillary nr. – c5,c6
Circumflex nr.
A large terminal br.
No supply in axilla.
Br.to shoulder jt.
Ant. & post div.
24. FROM POST CORD contd…
Radial nr. – c5,c6,c7,c8,T1
Cont.of post cord
Largest in the whole plexus
Gives post cut nr. Of forearm.
25. VARIATIONS
GREATEST VARIATION IN FORMATION
OCCURS IN LATERAL CORD
10% OF CASES MUSCULOCUT. N. MAY
ARISE AS 2-3 BRANCHES
LATERAL ROOT OF MEDIAN N. MAY
ARISE AS 2-3 BRANCHES
26. BLOOD SUPPLY
From subclavian & vertebral art.
Vertebral art.- c5, c6. & more proximal
cervical nerves
C8, T1,- br. From costocervical trunk.
27. MICRO ANATOMY
120,000-150,000 Myelinated fibres
C5 &T1-least no. of myelin.fibres
C8 –largest no. of myelin.fibres.
Proportion of motor fibres highest in c5, then
c8 & least in c7 & t1.
Sensory greatest in c7, then c6, then c8.
Segregation of nr fibres well established
proximally.
28. PREFIXATION & POSTFIXATION
PREFIXED: CONTRIBUTION FROM C4 IS
LARGE ,T2 IS OFTEN ABSENT
POSTFIXED: CONTRIBUTION FROM T1
IS LARGE, T2 IS ALWAYS PRESENT,C4 IS
ABSENT,C5 IS REDUCED IN SIZE
32. BRACHIAL PLEXUS SHEATH
C.t. of prevertebral fascia
Blends with fascia of biceps & brachialis.
C.t. septae compartmentalize components of
the sheath.
Controversies – septae may limit spread of
solutions during BP block.
33. Brachial Plexus Branches &
Muscular Innervations
Dorsal Scapular N.
Levator Scapulae
Rhomboid Major/Minor
Lateral Pectoral N.
Pectoralis Major/Minor
Suprascapular N.
Infraspinatus
Supraspinatus
Musculocutaneous N.
Biceps Brachii
Brachialis
Coracobrachialis
34. Brachial Plexus Branches &
Muscular Innervations
Axillary N.
Deltoid
Teres Minor
Upper Subscapular N.
Subscapularis
Middle Subscapular or
Thoracodorsal N.
Latissimus Dorsi
Lower Subscapular N.
Subscapularis
Teres Major
48. TRANSITIONAL ZONE
BERTHOLD (1993):JUNC. b/w ROOTS AND
SPINAL CORD
A CENTRAL-PERIPHERAL TRANSITIONAL
ZONE
2 TYPES OF INTRADURAL INJURY-
RUPTURE AND AVULSION
49. RUPTURE & AVULSION
INTRADURAL RUPTURE IS TEARING OF
ROOTLETS AT OR PERIPHERAL TO T.Z
AVULSION IS ROOTLETS ARE TORN
FROM SPINAL CORD ITSELF AND INJURY
IS CENTRAL TO TRANSITIONAL ZONE .
50.
51.
52.
53.
54.
55.
56.
57.
58.
59. UPPER PLEXUS INJURY (ERB’S
PARALYSIS)
LOWER PLEXUS INJURY(KLUMPKE’S
PARALYSIS)
INJURY AT LEVEL OF ROOTS