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.
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. 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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Differences between Sympathetic and Parasympathetic Nervous System (With Table)
| Basic Terms | Sympathetic Nervous System | Parasympathetic Nervous System |
| Meaning | Prepare the body to respond to fight and flight | Prepare the body to respond to rest and digest |
| Origin | The lumbar and thoracic region of the spinal cord | Sacral region of spinal cord, medulla, and cranial nerves |
| Role | Control body response during perceive dangers or threats | Control the body response at rest |
| Activated Responses | Fight and flight | Rest and digest |
| Body Response | Speed up heart rate and general body tense | Restore the body to a state of calmness |
| Heat Rate | Increases | Decreases |
| Skeletal Muscle System | Muscle contract | Muscle relax |
| Pulmonary System | Bronchial tubes Dilate | Bronchial tubes Constrict |
| Pupils | Dilate | Constrict |
| G.I | Decreases stomach movement and secretions | Increases stomach movement and secretions |
| Effect on Blood Flow | Increases | Decreases |
| Time of dormancy | During dangers | At rest |
| Effect on rectum | Contract | Relax |
| Urinary output effect | Decreases | Increases |
| Rate of conversion of glycogen to glucose | Increases conversion of glycogen to glucose for muscle contraction | No action |
| Adrenal Gland | Releases adrenaline | No release of adrenaline |
| Salivary Glands | Decreases saliva production | Increases saliva production |
| Neurotransmitters | Are adrenergic such as epinephrine. | Are cholinergic such as acetylcholine. |
| Anal sphincter | Contract | Relax |
What is the Sympathetic Nervous System?
The sympathetic nervous system is a crucial component of the autonomic nervous system, responsible for the body’s “fight or flight” response in reaction to stress, danger, or challenging situations. This complex network of nerves and ganglia coordinates involuntary physiological responses to prepare the body for immediate action.
When the sympathetic nervous system is activated, a series of physiological changes occur to enhance the body’s ability to cope with stressors. These changes include the release of the neurotransmitter norepinephrine, which stimulates various target organs and tissues. The heart rate increases, leading to a surge in blood flow to muscles, preparing the body for physical exertion. Airway passages dilate to maximize oxygen intake, and the release of glucose into the bloodstream is heightened to provide a rapid energy source.
Other effects of sympathetic activation include the dilation of the pupils, inhibition of digestive functions, and increased sweating. These responses collectively contribute to an organism’s ability to respond rapidly and effectively to challenging situations, whether it involves escaping from a threat or engaging in physical activity.
The sympathetic nervous system works in concert with the parasympathetic nervous system to maintain homeostasis, ensuring that the body can adapt to a range of environmental stressors while also allowing for periods of rest and recovery. Dysfunction in the sympathetic nervous system can contribute to various health conditions, highlighting its significance in the overall regulation of physiological responses.
What is the Parasympathetic Nervous System?
The parasympathetic nervous system is a vital component of the autonomic nervous system, responsible for regulating involuntary physiological processes during periods of rest, recovery, and digestion. Often referred to as the “rest and digest” system, the parasympathetic nervous system counterbalances the effects of the sympathetic nervous system, promoting relaxation and conservation of energy.
When activated, the parasympathetic nervous system releases the neurotransmitter acetylcholine, which acts on target organs and tissues to induce calming and restorative responses. The heart rate decreases, allowing the body to conserve energy. Airway passages constrict, and digestive functions are enhanced, promoting optimal nutrient absorption and digestion. The parasympathetic system also stimulates activities such as salivation and lacrimation.
Additionally, the parasympathetic nervous system plays a crucial role in facilitating recovery and maintaining homeostasis. It promotes a state of relaxation, reduces stress hormone levels, and supports various bodily functions necessary for overall well-being. This includes immune system activity, which is often prioritized during restful periods.
The dynamic interplay between the sympathetic and parasympathetic nervous systems ensures that the body can adapt to different environmental and internal cues. Dysfunction in the parasympathetic system can impact various physiological processes and is associated with conditions such as autonomic neuropathy. Understanding the balance between these two systems is essential for comprehending the regulation of involuntary bodily functions.
Differences between Sympathetic and Parasympathetic Nervous System
- The sympathetic nervous system has small preganglionic nerve fiber while parasympathetic have larger ones.
- The sympathetic nervous system causes the pupil to dilate while the parasympathetic nervous system causes the pupil to constrict.
- The sympathetic nervous system increases saliva production while the parasympathetic causes a decrease in saliva production.
- The parasympathetic nervous system causes the anal sphincter to relax while the sympathetic nervous system causes the anal sphincter to contract.
- Urinary bladder during the sympathetic nervous system tends to relax while parasympathetic make them contract.
- The parasympathetic nervous system stimulates gut peristalsis while the sympathetic nervous system inhibits gut peristalsis.
- The sympathetic nervous system tends to increase heart rate while the parasympathetic nervous system decreases heart rate.
Similarities between Sympathetic and Parasympathetic Nervous System
- Both are the autonomous nervous system
- Both originated from the spinal cord
- Both have an influence on the body physiological process
- 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 sympathetic and parasympathetic nervous systems are two branches of the autonomic nervous system, each responsible for regulating involuntary physiological processes in the body. These systems operate in a coordinated manner to maintain homeostasis, but they have distinct functions, neurotransmitters, and effects on various organ systems.
The sympathetic nervous system is often associated with the “fight or flight” response, activating the body in response to stress or danger. It increases heart rate, dilates airways, redirects blood flow to muscles, and releases energy stores. Neurotransmitters such as norepinephrine and epinephrine mediate the effects of the sympathetic system. This response prepares the body for quick and intense physical activity, enabling it to respond to challenging situations.
Conversely, the parasympathetic nervous system is linked to the “rest and digest” response, promoting relaxation and recovery. It decreases heart rate, constricts airways, and enhances digestion and nutrient absorption. Acetylcholine is the primary neurotransmitter involved in parasympathetic signaling. The parasympathetic system predominates during periods of rest, allowing the body to conserve energy, recover, and carry out essential functions such as digestion and immune system activity.
In summary, the sympathetic and parasympathetic nervous systems represent the two arms of the autonomic nervous system, working in opposition to maintain balance and respond to different physiological demands. The sympathetic system prepares the body for action in stressful situations, while the parasympathetic system promotes relaxation and recovery during periods of rest. Their dynamic interplay ensures the body’s adaptability to a range of environmental and internal cues.
More Sources and References
- Autonomic Nervous System. Wikipedia
- Physiology of the Autonomic Nervous System. NCBI
- Your Parasympathetic Nervous System Explained. Healthline