Which area is primarily supplied by the C5 sensory fibers?

Which area is primarily supplied by the C5 sensory fibers?

• A. Medial forearm
• B. Lateral arm
• C. Thumb
• D. Shin

Answer: (B)

Spinal nerve dermatomes explain this. C5 covers the lateral aspect of the upper arm, around the deltoid region. That area is where sensation from the C5 nerve root is primarily felt. The other regions map to different roots: the medial forearm is mainly C8/T1, the thumb is primarily C6, and the shin corresponds to L4/L5. So the lateral arm is the area mainly supplied by C5 sensory fibers.

Spinal nerve dermatomes explain this. C5 covers the lateral aspect of the upper arm, around the deltoid region. That area is where sensation from the C5 nerve root is primarily felt. The other regions map to different roots: the medial forearm is mainly C8/T1, the thumb is primarily C6, and the shin corresponds to L4/L5. So the lateral arm is the area mainly supplied by C5 sensory fibers.