MAJOR MIXED NERVES |
From the brachial and lumbosacral plexi, the major nerves of the upper
and lower extremities are derived, respectively. There are several large mixed
(i.e., containing motor and sensory fibers) nerves that every medical student
should be familiar with. |
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Median Nerve
• Root Derivation
C6-T1
• Plexus Derivation
Upper, middle and lower trunks
Lateral and medial Cords
• Major Motor Function
Wrist and finger flexion
Arm pronation
Thumb opposition and abduction
• Major Sensory
Distribution
Volar thumb, index, middle and lateral ring fingers
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Ulnar Nerve
• Root Derivation
C8-T1
• Plexus Derivation
Lower trunk
Medial cord
• Major Motor Function
Intrinsic hand muscles
Distal finger flexion of ring and little fingers
Wrist flexion medially
• Major Sensory
Distribution
Volar little finger and medial ring fingers
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Radial
Nerve
• Root Derivation
C5-C8
• Plexus Derivation
Upper, middle and lower trunks
Posterior cord
• Major Motor Function
Elbow extension
Wrist and finger extension
Elbow flexion
• Major Sensory
Distribution
Dorsal thumb, index, middle and lateral ring
fingers
Posterior forearm and arm
Lateral arm
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Musculocutaneous
Nerve
• Root Derivation
C5-C6
• Plexus Derivation
Upper trunk
Lateral cord
• Major Motor Function
Elbow flexion
Arm supination
• Major Sensory
Distribution
Lateral forearm
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Axillary
Nerve
• Root Derivation
C5-C6
• Plexus Derivation
Upper trunk
Posterior cord
• Major Motor Function
Shoulder abduction and external rotation
• Major Sensory
Distribution
Lateral shoulder
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Femoral
Nerve
• Root Derivation
L2-L4
• Plexus Derivation
Lumbar plexus
• Major Motor Function
Knee extension
Hip flexion
• Major Sensory
Distribution
Anterior and medial thigh
Medial calf
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Sciatic
Nerve
• Root Derivation
L4-S3
• Plexus Derivation
Lower lumbosacral plexus
• Major Motor Function
Knee flexion
Ankle dorsiflexion and plantarflexion
Ankle inversion and eversion
• Major Sensory
Distribution
Lateral and posterior calf
Dorsum and sole of the foot |