20 Differences between Sympathetic and Parasympathetic Nervous System

The human body has an autonomic nervous system. It is responsible in controlling body processes such as blood circulation, heartbeat, urination, digestion, and more. 

The name autonomic nervous system is due to autonomously working function. It works without human conscious effort. 

The key role of the autonomic nervous system is to enhance homeostasis. It is further grouped into sympathetic and parasympathetic nervous systems.

So, what is the main difference between sympathetic and parasympathetic nervous systems? The former prepares the body to respond to fight and flight while the latter prepares the body to respond to rest and digest. 

This article provides further differences between the sympathetic and parasympathetic nervous systems in a tabular form. Take the time to study the table and get to more about their similarities. 

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Comparison Table( Sympathetic Vs Parasympathetic Nervous System)

Basic TermsSympathetic Nervous SystemParasympathetic Nervous System
MeaningPrepare the body to respond to fight and flightPrepare the body to respond to rest and digest
OriginThe lumbar and thoracic region of the spinal cordSacral region of spinal cord, medulla, and cranial nerves
RoleControl body response during perceive dangers or threatsControl the body response at rest
Activated ResponsesFight and flightRest and digest
Body ResponseSpeed up heart rate and general body tenseRestore the body to a state of calmness
Heat RateIncreasesDecreases
Skeletal Muscle SystemMuscle contractMuscle relax
Pulmonary SystemBronchial tubes DilateBronchial tubes Constrict
PupilsDilateConstrict
G.IDecreases stomach movement and secretionsIncreases stomach movement and secretions
Effect on Blood FlowIncreasesDecreases
Time of dormancyDuring dangersAt rest
Effect on rectumContractRelax
Urinary output effectDecreasesIncreases
Rate of conversion of glycogen to glucoseIncreases conversion of glycogen to glucose for muscle contractionNo action
Adrenal GlandReleases adrenalineNo release of adrenaline
Salivary Glands         Decreases saliva productionIncreases saliva production 
NeurotransmittersAre adrenergic such as epinephrine.Are cholinergic such as acetylcholine.
Anal sphincterContractRelax

What is the Sympathetic Nervous System?

The sympathetic nervous system is part of the autonomic nervous system that tends to prepare the body in advance for stresses such as threats and injuries.

The nervous system makes the heart rate increase and muscles contract. The nervous system originates from the spinal cord specifically the lumbar and thoracic region.

In general terms, the autonomic nervous system help to perceive how the body will react to impending danger.

What is the Parasympathetic Nervous System?

The parasympathetic nervous system is another part of the autonomic system that helps to control the various functions of the body at rest.

The nervous system normally causes the muscles to relax and the heart rate to decrease. Besides that, it helps to maintain homeostasis in the body.

According to research, the autonomic nervous system originates from the spinal cord and the medulla. All in all, it helps to maintain the rest and digest function of the body.

Differences between Sympathetic and Parasympathetic Nervous System

  1. The sympathetic nervous system has small preganglionic nerve fiber while parasympathetic have larger ones.
  2. The sympathetic nervous system causes the pupil to dilate while the parasympathetic nervous system causes the pupil to constrict.
  3. The sympathetic nervous system increases saliva production while the parasympathetic causes a decrease in saliva production.
  4. The parasympathetic nervous system causes the anal sphincter to relax while the sympathetic nervous system causes the anal sphincter to contract.
  5. Urinary bladder during the sympathetic nervous system tends to relax while parasympathetic make them contract.
  6. The parasympathetic nervous system stimulates gut peristalsis while the sympathetic nervous system inhibits gut peristalsis.
  7. The sympathetic nervous system tends to increase heart rate while the parasympathetic nervous system decreases heart rate.

Similarities between Sympathetic and Parasympathetic Nervous System

  1. Both are the autonomous nervous system
  2. Both originated from the spinal cord
  3. Both have an influence on the body physiological process
  4. Both play a significant role in the homeostasis of the body

Frequently Asked Questions

  • Is Sympathetic or Parasympathetic Faster?

The parasympathetic nervous system has a quicker ability to respond to change than the sympathetic nervous system. 

  • Can the Parasympathetic and Sympathetic Work at the Same Time?

The parasympathetic and sympathetic systems do not work entirely separately, but rather work at the same time, often in opposition to one another.

  • Is Sweating Parasympathetic or Sympathetic?

The sympathetic nervous system normally controls facial sweating. But there are instances where parasympathetic reflexes provoke pathological sweating.

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Summary

The body reflects action is controlled by the autonomous nervous system. The ANS comprises both the sympathetic and parasympathetic nervous systems. These two systems play a significant role in the internal body organs such as the stomach, intestines, and heart.

More Sources and References

  1. Autonomic Nervous System. Wikipedia 
  2. Physiology of the Autonomic Nervous System. NCBI
  3. Your Parasympathetic Nervous System Explained. Healthline 

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