Peripheral Nervous System | Cannabis Wiki
The peripheral nervous system contains afferent (sensory) nerves that carry impulses from the body to the central nervous system, and efferent (motor) nerves that carry impulses from the body to the central nervous system to the muscles and glands, causing the target organs to do something in response to the commands received.
The peripheral nervous system is further broken down into the somatic nervous system and the autonomic nervous system. The somatic nervous system (SNS) provides voluntary control over skeletal muscle contractions, and the autonomic nervous system (ANS) provides involuntary control over smooth muscle, cardiac muscle, and glandular activity and secretions in response to the commands of the central nervous system.
The autonomic nervous system contains two types of nerves: sympathetic and parasympathetic. Sympathetic nerves regulate involuntary, essential body functions such as increasing the heart rate, constricting blood vessels, and raising the blood pressure; responding to the “fight-or-flight response“, the body prepares to deal with immediate threats to the internal environment.
The parasympathetic nerves regulate involuntary, essential body functions such as slowing the heart rate, increasing peristalsis of the intestines, increasing glandular secretions, and relaxing sphincters, this serving as a complement to the sympathetic nervous system and returning the body to a more restful state.