Learning Objective

Understand the structure, subdivisions, and general functions of the autonomic nervous system (ANS).

Autonomic Nervous System (ANS)

The ANS is the major involuntary component of the nervous system, regulating unconscious bodily functions such as:

• Heart rate and blood pressure
• Gastrointestinal motility and secretion
• Genitourinary function

Parasympathetic Nervous System (PANS)

• Often called the “rest-and-digest” system
• Promotes energy conservation and routine maintenance of body functions

Sympathetic Nervous System (SANS)

• Often called the “fight-or-flight” system
• Prepares the body for stress, emergencies, and physical activity

Quick Tip / Mnemonic

• “PANS = Peace / Rest & Digest, SANS = Stress / Fight & Flight”

Activity