The Nervous System: Components, Roles & Conditions

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The body’s nervous system is comprised of two major components: the central nervous system (CNS) and the peripheral nervous system (PNS). These two parts of the nervous system act together to ensure your body is communicating all of its sensory information and requirements. The central nervous system and the peripheral nervous system play unique roles in controlling the body’s function.


The nervous system utilizes nerve cells known as neurons to send signals all over your body. These electrical signals travel among your brain, organs, skin, glands and muscles.

The messages assist in the movement of the limbs and feeling sensations such as Pain. The ears, eyes, tongue, nose and the nerves all over the body grasp information about your environment. Then, nerves transport the data to and from the brain. 

There are three types of neurons: motor neurons, sensory neurons, and interneurons.

Motor neurons: 

They take signals from the brain and spinal cord to the muscles. They assist in the body movement. They also help with swallowing, breathing, and speaking.

Sensory neurons:

They grasp information from the senses (what you see, taste, touch, etc.) to the brain.

Interneurons :

Interneurons communicate between motor and sensory neurons. These neurons manage the movement in response to sensory information (like moving away from a hot surface) and play a significant role in how you think, learn, and remember.


Central Nervous System

The central nervous system (CNS) comprises the brain, cerebellum, and spinal cord.

The Spinal Cord

The spinal cord is responsible for directing signals from the brain to the body and is able of controlling simple reflexes devoid of transmitting information from the brain.

The Brain

The brain processes the majority of the body’s sensory information and is in charge of coordinating conscious and unconscious body functions like thinking, feeling and maintaining haemostasis, which is the body’s ability to manage a stable environment. The brain consists of three regions: the forebrain, the midbrain and the hindbrain.

The Forebrain

The forebrain is responsible for processing the information required to complete complex cognitive tasks. The parts of the forebrain are in charge of speech, sensory functions, voluntary motor skills and critical thinking. 

Also, it controls homeostasis, which is maintained via the regulation of body temperature, pleasure, blood pressure, hunger, thirst, Pain, as well as hormone generation.

The Midbrain

The midbrain connects the forebrain and the hindbrain and does the crucial job of connecting the brain to the spinal cord. It is responsible for processing sounds and sights and works to control the movement of the eye.

The Hindbrain

The hindbrain is in charge of muscular movement, heart rate, respiratory rhythm, blood pressure, sleep and staying alert while awake. Involuntary reflexes such as sneezing and swallowing are also managed by three parts of the hindbrain.

Peripheral Nervous System

The peripheral nervous system comprises nerves, which are responsible for sending signals to and from the central nervous system, muscles, the body’s organs and senses. The peripheral nervous system can be divided into the somatic nervous system and the autonomic nervous system.

Somatic Nervous System

The somatic nervous system is comprised of motor neurons and sensory neurons that assist the body perform voluntary activities.

Autonomic Nervous System

The autonomic nervous system is comprised of neurons that are responsible for connecting the central nervous system with the body’s internal organs. It can be classified into two components: the sympathetic nervous system and the parasympathetic nervous system.

Sympathetic Nervous System

The sympathetic nervous system activates what is called as the flight or flight response in the body. It equips the body’s energy for stressful or energy-exerting activities.

Parasympathetic Nervous System

The parasympathetic nervous system is responsible for conserving energy. It alerts the body to conserve its energy during sleep and relaxation.


What does the nervous system do?

The primary function of your nervous system is to send messages from various parts of your body to your brain and from your brain back out to your body to tell your body what to do. 

These messages manage you:

  • Memory, Thoughts, learning and feelings
  • Heartbeat and breathing patterns
  • Movements (balance and coordination)
  • Senses (how your brain interprets what you see, hear, touch, taste, and feel)
  • Sleep
  • Digestion
  • Wound healing
  • Response to stressful situations, such as sweat production
  • Body processes, like puberty and ageing

Diseases of the Central Nervous System

There are different problems and diseases that can affect the central nervous system. Disease or damage to the central nervous system can create a range of impacts. Some of the conditions that can impact the central nervous system include:

Infections: Bacteria, viruses and fungi can infringe the central nervous system, creating symptoms or damage.

Degenerative Diseases: Diseases like Alzheimer’s disease and Parkinson’s disease can lead to the degeneration of cells in the key areas of the brain, affecting functions such as memory and movement.

Stroke:  A blockage or stoppage of blood flow to the brain stops oxygen from reaching the tissues of the brain. This leads to damage in the affected area and can lead to impairment or death.

Tumours: Cancerous and benign tumours can develop in different areas of the central nervous system. The effect of these tumours depends on their location and size.

 Symptoms of nervous system conditions

  • Movement and coordination changes
  • Memory loss
  • Difficulty with thinking and reasoning
  • Behavioral and mood changes
  • Pain, numbness, or a feeling of pins and needles
  • Seizures

Conditions that need immediate treatment:

  • Sudden vision loss
  • Muscle weakness or paralysis in one side of your body
  • Slurred speech
  • Confusion

Tests for the nervous system

  • Computed tomography (CT) scan
  • Lumbar puncture (spinal tap)
  • Magnetic resonance imaging (MRI) scans
  • Electrocardiogram (ECG or EKG)
  • Electroencephalogram (EEG)


Your doctor will review the symptoms to diagnose and treat any conditions that affect your nervous system. Treatment differs for each condition. Hence, your doctor will take into consideration several factors, like your age and general health, to formulate your treatment plan. This plan may include:

  • Having surgery
  • Taking medications
  • Receiving supportive care 
  • Participating in counselling for mental and emotional support

How to keep your nervous system healthy?

  • Seeing your doctor regularly.
  • Avoid harmful substances like tobacco.
  • Maintain good health, like eating a balanced diet.
  • Wear protective gear or equipment (a helmet) when playing sports or participating in certain activities.
  • Managing any underlying health conditions.


The nervous system works as the central control system for the entire body, enabling critical functions like learning, cognition, movement and memory. This extensive network of nerves interconnects with all your organs, glands, and muscles, necessitating proper maintenance to ensure optimal functionality. 


1. What are the components of the nervous system?

The nervous system comprises of the brain, spinal cord, and a complex network of nerves. This system sends signals back and forth between the brain and the rest of the body. The brain works as a command centre and controls all the body’s functions.

2. What are the four main functions of the nervous system?

– Reception of general sensory information (touch, temperature, pressure, pain, vibration).
– Receiving and perceiving unique sensations (taste, vision, smell, sounds).
– Integration of sensory information from various parts of the body and processing them.
– Response generation.


The Information including but not limited to text, graphics, images and other material contained on this blog are intended for education and awareness only. No material on this blog is intended to be a substitute for professional medical help including diagnosis or treatment. It is always advisable to consult medical professional before relying on the content. Neither the Author nor Star Health and Allied Insurance Co. Ltd accepts any responsibility for any potential risk to any visitor/reader.

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