Parasympathetic nervous system

Definition

The parasympathetic nervous system (PNS) is a division of the autonomic nervous system responsible for rest and digest functions. It helps conserve energy by slowing the heart rate, increasing intestinal and gland activity, and relaxing sphincter muscles in the gastrointestinal tract.

5 Must Know Facts For Your Next Test

1. The PNS is primarily involved in stimulating digestive secretions, such as saliva, gastric juice, and bile.
2. Acetylcholine is the primary neurotransmitter used by the PNS to communicate with target organs.
3. The vagus nerve is a major component of the PNS and plays a crucial role in controlling heart rate and digestive processes.
4. Proper nutrition can enhance PNS function by providing essential nutrients like B vitamins which support neurotransmitter production.
5. Imbalances in the PNS can lead to conditions such as irritable bowel syndrome (IBS) and other digestive disorders.

Review Questions

• What functions are primarily controlled by the parasympathetic nervous system?
• Which neurotransmitter is most associated with the parasympathetic nervous system?
• How can proper nutrition impact the functioning of the parasympathetic nervous system?

Related terms

Autonomic Nervous System: The part of the nervous system that controls involuntary actions, including both sympathetic and parasympathetic divisions.

Vagus Nerve: A key component of the parasympathetic nervous system that regulates heart rate, digestion, and respiratory rate.

Acetylcholine:

A neurotransmitter used by the parasympathetic nervous system to communicate with target organs.