The part of the nervous system that controls voluntary activities is the

somatic nervous system

Explanation:

The motor division of the peripheral nervous system includes a somatic nervous system and an autonomic nervous system. The somatic nervous system (SNS) delivers motor information from the central nervous system to skeletal muscles only. Therefore, the motor responses of the somatic nervous system are consciously controlled by humans. This makes it control the voluntary actions of the body. The somatic nervous system includes the somatic motor neurons that connect the skeletal muscles with the central nervous system.