UPPER LIMB
BRACHIAL PLEXUS
- The brachial plexus is a network of nerves that provides movement and feeling to the shoulder, arm
and hand. - The nerves supporting the arm exits the spinal column high in the neck and the nerves that support the hand and fingers exit lower in the neck.
- This nerve complex comprises four cervical nerve roots (C5-C8) and the first thoracic nerve root (T1). These roots combine to form three trunks. Each nerve root is derived from the corresponding ventral or primary rami of the spinal nerve. C5-C6 form the upper trunk, C7 continues as the middle trunk and C8-T1 form the lower trunk.
- Each trunk splits and forms a division. Half of them supply flexor muscles (that lift and bend the arm) and the rest supply the extensor muscles (that straighten the arm and bring it down).
- The anterior divisions of the upper and middle trunk unite to form the lateral cord;
- The anterior division of the lower trunk continues as the medial cord and all 3 posterior divisions unite forming the posterior cord. The nerve cords derive their names with respect to their relationship with the axillary artery.
- The lateral cord lies on the lateral (or outer) side of the axillary artery; the medial cord lies on the medial (or inner) side of the axillary artery and the posterior cord lies behind the axillary artery.
- The cords then branch out forming different nerves that supply all of the muscles of the upper extremity.
BRANCHES OF BRACHIAL PLEXUS
- Branches of the Roots:
- Nerve to serratus Anterior (Long Thoracic N of Bell),(C5,C6,C7)
- Nerve to rhomboideus (Dorsal scapular.N),(C5)
- Branches of the Trunks:
- N (C5,C6)
- Nerve to Subclavius (C5,C6)
- Branches of the cords:
- Branches of Lateral cord (LML)
- Lateral Pectoral. N(C5 – C7)
- Musculo – Cutaneous. N (C5 – C7)
- Lateral root of Median. N (C5 – C7)
- Branches of Lateral cord (LML)
- Branches of Medial cord (M4U)
- Medial Pectoral.N (C8,T1)
- Medial Cutaneous. N of arm (C8,T1)
- Medial Cutaneous. N of fore – arm (C8,T1)
- Medial root of median. N (C8,T1)
- Ulnar.N (C7,C8,T1)
- Branches of Posterior cord (ULNAR)
- Upper Subscapular (C5,C6)
- Lower Subscapular (C5,C6)
- Nerve to Latissmus dorsi (thoraco-dorsal)(C6,C7,C8)
- Axillary.N (C5,C6)
CLINICAL POINTS
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