Human Physiology Lecture Notes

Difference between Sympathetic and Parasympathetic Nervous Systems


difference between parasympathetic and sympathetic nervous system

Sympathetic vs Parasympathetic Nervous Systems
(Similarities and Differences between Sympathetic and Parasympathetic Nervous Systems)

The involuntary or reflex functions in the body are controlled by a part of peripheral nervous system called Autonomous Nervous System (ANS). ANS regulate the functions of internal organs (visceral functions) particularly the functions of heart, stomach and intestine.  The Autonomic Nervous System composed of two components:

            (1). Sympathetic Nervous System (SNS)

           (2). Parasympathetic Nervous System (PNS or PSNS)

Sympathetic Nervous System (SNS): They are the part of ANS which originate from the spinal cord of the thoracic and lumbar region. They control the ‘fight-or-flight’ response or the ‘sympatho-adrenal response’ in the body. SNS prime the body for acting in threatening situations for survival. The sympathetic nervous system acts in the body as complementary to the action of Parasympathetic Nervous System.

Parasympathetic Nervous System (PNS or PSNS): Part of ANS originates from the spinal cord and medulla which control the ‘rest-and-digest’ or ‘feed-and-breed’ activities in the body. They act in the body as complementary to the action of SNS.

The present post describes the similarities and differences between Sympathetic Nervous System and Parasympathetic Nervous System

Similarities between Sympathetic and Parasympathetic Nervous System

Ø  Both are the part of ANS.

Ø  Both originate from the spinal cord.

Ø  Both have huge influence on physiological process of the body such as respiration, circulation, digestion, urination and reproduction.

Ø  Both have role in maintaining the homoeostasis of the body.

Ø  Both composed of pre-ganglionic and post-ganglionic neurons.

Difference between Sympathetic and Parasympathetic Nervous System

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