Parasympathetic Vs Sympathetic

The parasympathetic nervous system is one of the two main divisions of the autonomic nervous system (ANS). Its general function is to control homeostasis and the body's rest-and-digest response.

The sympathetic nervous system (SNS) is one of two main divisions of the autonomic nervous system (ANS). Its general action is to mobilize the body's fight-or-flight response.

Control the body's response while at rest.

Control the body's response during perceived threat.

Spinal cord, medulla

Spinal cord, thoracic and lumbar spinal cord

Rest and digest

Fight-or-flight

Longer pathways, slower system

Very short neurons, faster system

Counterbalance; restores body to state of calm.

Body speeds up, tenses up, becomes more alert. Functions not critical to survival shut down.

Decreases heart rate

Increases contraction, heart rate

Bronchial tubes constrict

Bronchial tubes dilate

Muscles relax

Muscles contract

Constrict

Dilate

Increases stomach movement and secretions

Decreases stomach movement and secretions

Saliva production increases

Saliva production decreases

No involvement

Releases adrenaline

No involvement

Increases; converts glycogen to glucose for muscle energy

Increase in urinary output

Decrease in urinary output