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Parasympathetic Nervous System

Definition

The parasympathetic nervous system is one of three divisions of the autonomic nervous system. Sometimes called the rest and digest system, it conserves energy as it slows heart rate, increases intestinal and gland activity, and relaxes sphincter muscles in gastrointestinal tract.

Analogy

Imagine you've just finished running a marathon (thanks to your sympathetic nervous system). Now you're sitting down for a well-deserved rest and meal - that's your parasympathetic nervous system kicking in!

Related terms

Sympathetic Nervous System: This division prepares the body for 'fight or flight' during any potential danger. It's like hitting the gas pedal in your car when you need to speed up quickly.

Homeostasis: This refers to maintaining internal balance in the body. It's like keeping your house at just right temperature - not too hot, not too cold!

Acetylcholine (ACh): A neurotransmitter involved in learning, memory and muscle contractions. It’s like the messenger delivering instructions from your brain to your muscles.