What is a myotome?

What is a myotome?

• A. Skeletal muscles innervated by motor axons in a given spinal root
• B. Skin areas innervated by sensory neurons
• C. Afferent reflex arc
• D. Vascular territory

Answer: (A)

A myotome is the group of skeletal muscles innervated by motor neurons from a single spinal nerve root. This concept lets clinicians map motor function to specific nerve roots and pinpoint where a lesion may be along the spinal cord or along a nerve root. For example, testing elbow flexors evaluates the muscle groups served by certain cervical roots, helping infer which root might be affected. This is different from a dermatome, which refers to the skin region supplied by sensory fibers from a single root. An afferent reflex arc describes a reflex pathway, not a muscle group, and a vascular territory concerns blood supply, not nerve innervation.

A myotome is the group of skeletal muscles innervated by motor neurons from a single spinal nerve root. This concept lets clinicians map motor function to specific nerve roots and pinpoint where a lesion may be along the spinal cord or along a nerve root. For example, testing elbow flexors evaluates the muscle groups served by certain cervical roots, helping infer which root might be affected. This is different from a dermatome, which refers to the skin region supplied by sensory fibers from a single root. An afferent reflex arc describes a reflex pathway, not a muscle group, and a vascular territory concerns blood supply, not nerve innervation.