The nervous system is defined as the command centre of the body. It is a complex network of nerves and cells, the primary function of which is to carry the message to and from the brain and spinal cord to other parts of the human body. Originating from an organism’s brain, it controls the organism’s movements, thoughts, and automatic responses to the things or actions around you. It also controls other body systems, including the digestion system, respiratory system, reproduction system, and sexual development. 

In What Parts The Nervous System Is Categorised?

The nervous system of an organism is categorised into two parts: the central nervous system and the peripheral nervous system. 

Central Nervous System: 

The central nervous system, called the central processing unit of the body, is responsible for instigating information, commands, and coordinates and influences all actions and activities within the body of an organism. The central nervous system is formed of two parts and these are:

  • The brain: The brain is considered the most significant organ in the organism and lies within the skull. It has a shape similar to the mushroom. The brain is further divided into four main parts:
  • the brain stem
  • the cerebrum
  • the cerebellum
  • the diencephalon
  • The spinal cord: The spinal cord extends from the base of the skull down to the centre of the back of an organism. It is a long tube-like structure composed of a series of 31 segments. The spinal cord is covered by three thin layers of protective tissue called membranes. It is home to both motor and sensory nerves. When it comes to the measurement, the spinal cord in adult women is about 43 cm long and 45 cm long in adult men. 

 Peripheral Nervous System: 

The peripheral nervous system includes parts other than the brain and spinal cord. The bundle of nerves in this particular system works as the conductor of the information to and from the central nervous system. The peripheral nervous system is further is categorised into two parts:

  • Somatic Nervous System: Peripheral nerve fibres are the part of the somatic nervous system, the primary function of which is to pick up sensory information from the distant organs of an organism (placed far away from the brain) and carry the particular information to the central nervous system. Also, the somatic nervous system consists of the motor nerve fibres, the primary function of which is to transfer the message from the brain for the movement and necessary action to the skeletal muscles. 
  • Autonomic Nervous System: The primary function of the autonomic nervous system is to control the nerves of the inner organs or processes of the organism’s body, on which usually there is no conscious control of an organism. These include digestion, blood circulation, breathing, heartbeat, etc. the autonomic nervous system is further categorised into three types:
  • The sympathetic nervous system: Neurons present within the sympathetic nervous system is responsible for preparing an organism’s body to react to something in the surroundings. It regulates the fight-or-flight responses in the body. The sympathetic nervous system increases the heart rate of an individual to prepare them to escape from danger. 
  • The parasympathetic nervous system: The parasympathetic nervous system of the organism is responsible for maintaining normal functions and conserving the body’s physical resources when it is at rest.
  • The enteric nervous system: The enteric nervous system is confined to the gastrointestinal tract of the organism’s body. 

What Are The Functions Of The Nervous System?

There are four main functions of the nervous system of an organism and these are explained as follows:

  • Sensation:

It is the primary function of the nervous system of the human body. Information about all the changes in the environment is received by the brain and spinal cord with the help of receptors (specialised nerve cells). The receptors are present in the entire body and are activated on the reception of a stimulus. 

 Response: 

This function deals with the response of an organism’s body generated by the brain after receiving a stimulus from the external environment. The most obvious reaction would be the movement of muscles.

  • Integration:

The integration process includes reception of the stimulus and processing of the response by comparing or integrating the received stimulus with other stimuli or memories of previous stimuli. 

  • Controlling the organism’s body:

It is the peripheral nervous system that controls the body of an organism. The somatic nervous system is responsible for controlling voluntary actions and the autonomic nervous system is responsible for controlling involuntary actions of the organism. 

Conclusion

If you are thinking of studying the different aspects of the human body, you should add the nervous system as a topic to your list. It is called the command centre of the human body because it is responsible for receiving a signal from the external environment and transferring the same to the brain. Not only does it receive the signal, but it also transfers commands or information from the brain to other parts of the human body. This article will provide you with all the necessary information about the body’s nervous system.