4 major functions of the nervous system

nervous system function
Here are the 4 main functions of the nervous system.

The 4 main functions of the nervous system are:

  1. Reception of general sensory information (touch, pressure, temperature, pain, vibration)
  2. Receiving and perceiving special sensations (taste, smell, vision, sounds)
  3. Integration of sensory information from different parts of the body and processing them
  4. Response generation

These major functions can again be divided into two major categories.

  1. Somatic functions, which people can control voluntarily, such as blinking of the eyelids
  2. Autonomic functions, which people cannot control, such as the beating of the heart

Sensation

  • This is the reception of all the changes happening in the surroundings that are received by parts of the brain.
  • The specialized nerve cells called receptors (which are part of neurotransmitters) are present all over the body.
  • They are activated on the reception of a stimulus (any change in the external environment) and send impulses (electrochemical pulses) to the spinal cord and brain via nerves. 
  • Examples include:
    • On touching a hot pan, the sensation is received by the sensory neurons present on the skin of the hand. These generate a signal that travels to the brain, and the necessary response from the motor neurons to remove the hand of the pan occurs.
    • Similarly, on smelling a foul smell, the nerve in the nose gets stimulated and the sensation is converted into an electrical signal, which travels to the brain.

Response

  • Deals with the response of the body, which the brain generates after receiving the sensations or stimuli.
    • The most common reaction is the movement of muscles to generate the appropriate response via the nerves coming from the brain or the spinal cord until the muscles contract or relax.
    • Besides these small muscles, various glands release enzymes and hormones as a response activity of the nervous system.

Integration

  • This process includes the reception of the signal and the processing of the response. 
  • An example includes:
    • If a dog is coming at you and you see it from a distance, the signal of sight generated is transmitted to the brain by the nervous system, and the information is processed. Now, the necessary action of running happens when the nervous system triggers the muscles and the body moves.

Controlling of the body

  • This happens due to the somatic nervous system that controls all the voluntary actions and the autonomic nervous system that controls all the involuntary actions. 
  • An example of the autonomic nervous system includes:
    • In the case of the dog, the movement of the legs will be under voluntary control, but the increased heartbeat and sweating will come under autonomic nervous control.

What are the divisions of the nervous system?

The nervous system forms the most complex and diverse system of anatomy concerned with the regulation of almost all the activities performed by the body.

The major divisions of the nervous system consist of the following:

  • The central nervous system (CNS)
  • The peripheral nervous system (PNS)

CNS includes the higher centers of the brain and the spinal cord, whereas the peripheral system includes all the neurons coming out of the brainstem and spinal cord.

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Medically Reviewed on 10/26/2021
References
Mayo Clinic. Slide show: How your brain works. https://www.mayoclinic.org/brain/sls-20077047?s=6

Lemkuil BP, Drummond JC, Patel PM. 9 - Central Nervous System Physiology: Cerebrovascular. In, Hemmings HC, Egan TD, eds. Pharmacology and Physiology for Anesthesia, 2nd ed. Elsevier. 2019; 174-192. https://www.sciencedirect.com/science/article/pii/B9780323481106000090