Which function is primarily associated with the voluntary system of the PNS?

The function primarily associated with the voluntary system of the Peripheral Nervous System (PNS) is controlling muscle movements like talking. This aspect of the PNS is known as the somatic nervous system, which is responsible for conscious, voluntary control over skeletal muscles. It enables activities that require intentional motor control, such as walking, lifting objects, and performing complex actions like speaking, which involves the coordination of various muscle groups to articulate words and sounds.

In contrast, regulating heart rate is an involuntary action managed by the autonomic nervous system, which operates without conscious thought. Automatic digestion processes also fall under the autonomic functions that happen without voluntary control. Reflex actions involve automatic responses to stimuli, mediated by the spinal cord and brainstem, rather than through conscious control, indicating they are also part of involuntary processing.