Which muscle group is directly influenced by myotomes?

Myotomes refer to specific segments of muscle that are innervated by motor fibers originating from a single spinal nerve root. Each spinal nerve root contributes to the control of specific groups of muscles, organizing them into functional units. Therefore, all skeletal muscles in the body are influenced by myotomes, as they are all innervated by spinal nerves that originate from the spinal cord. This means that regardless of whether the muscles are in the upper body, lower body, or even around the abdomen, they are all influenced by the myotomal distribution of spinal nerves.

The connection between myotomes and skeletal muscles is essential for understanding how movement and motor function are coordinated throughout the body. Each muscle's activation is linked to its corresponding spinal motor neuron, which reflects the organization of myotomes. Thus, since all skeletal muscles receive innervation from spinal nerve roots that contribute to specific myotomes, the correct understanding aligns with the answer indicating that all skeletal muscles are influenced by these myotomes.