Motor System

Motor innervation from the spinal cord to the muscles of the leg.

The motor system is the part of the nervous system that controls voluntary movement. It consists of the brain, spinal cord and nerves that connect these structures to the effector muscles.

The human body has about 600 skeletal muscles, which produce movements at body joints. The brain gives commands to the muscles through nerves.

The nerve from which the command originates is located in the central nervous system. This nerve is called the upper motor neuron.

The axon of the upper motor neuron travels to either the brainstem or the spinal cord, where it synapses with the body of another motor neuron, called the lower motor neuron. The axon of the lower motor neuron then travels to the target tissue which it innervates, signaling to the muscle or muscle group that it needs to contract.

This chain of nerves is called a motor pathway.

The cerebellum and basal ganglia are also involved in the motor system by coordinating complex movements such as walking or running and maintaining balance.

Discover the exciting anatomy of the motor system in the following articles, or boost your anatomy studies with high-quality video tutorials and quizzes.