Pre MBBS Series : The Nervous System

Welcome to Prithvi’s Pre-MBBS article series. A list of articles that hope to provide very basic information about the functioning of the human body. These articles are written in a very easy to understand manner and are primarily aimed at Students who have just began their preparation for the NEET UG. If you’re class 11 or 12, the articles in this series will be the perfect appetizer you’ll need before you go about studying more in detail about the human body and biology in general.

Interesting Facts About Your Nervous System

The nervous system is probably one of the most advanced biological systems in existence. It is the command center of the body that co-ordinates all other bodily functions and other bodily systems as well like the respiratory system and digestive system.

  • How Many Nerve Cells Do You Have In Your Body ?–

The count of nerve cells in our body is in the billions, with a ‘B’. That’s 10^9!  There are different categories of nerve cells with different functions and lifespans. In an adult human brain, there are almost 100 billion nerve cells while there are almost 13.5 million in the spinal cord, all working in near perfect sync with one another. Just to put the number into perspective, if you started counting from zero all the way to say 100, it would take you 25 seconds ( We hired someone to count till 100 and timed them). If you were to count from zero to a billion, assuming you magically managed to do so continuously without taking any break in between, it would take you 95 years!

  • Nerve Cells and Their Parts –


The neuron is the basic working unit of the brain, a specialized cell designed to transmit information to other nerve cells, muscle, or gland cells

Neurons have three main parts: dendrites, the axon, and a cell body or soma. Neurons receive inputs in the form of electrochemical signals from other neurons with the help of their dendrites. Axons are the output structures of the neuron. When a neuron wants to send information to a neighboring neuron, it sends an electrochemical message known as “Action Potential” through the entire axon. The soma houses the nucleus of the Neuron which contains the neuron’s DNA material. Proteins are synthesized here to be transported throughout the dendrites and axon.

The above explanation is an overt simplification of the structure of the neuron. You will learn a lot more in detail once you ace the NEET and get a MBBS or BDS seat!

  • What About The Size and Shape Of Neuron?–

Not all neurons are created equal. They can be observed in different types of sizes or shapes based on their location. The location of the neuron determines its use case functionality and hence its shape, structure and lifespan. For example, the sensory neurons have dendrites on both of their ends.

  • What Functions Do Neuron Cells Perform ?

Are you contemplating the Function of  Neuron?. There are broadly 4 types of neurons classified based on function known as motor, receptors, sensory, and interneurons. Sensory Neurons for example cover the outer body parts such as the skin and muscles.

Motor neurons convey signals from the Brain to muscles and control their movement. The receptor neurons are designed to sense the environment beam information back to the brain. Interneurons are responsible to send messages from one neuron to another.

Given the basic definitions of the four broad classes of neurons, can you make an educated guess about what kind of neuron is most numerous in the body?

  • Nervous System And Their Locations –

The Nervous system as a whole can be divided into two categories based on location.

The Central Nervous System, abbreviated as CNS , consists of the brain in the skull and the spine.

The PNS, or Peripheral Nervous system, consists of the nerves that branch out of the Spine and Skull. These could include nerves at your fingertips and toes.

The extremely complicated nervous system does a phenominal job in co-ordinating the activities of the various sensory organs in our body. The  Sensory Organs are the gateways via which we perceive the world around us. The next article in the series with focus more in detail on the individual sensory organs in the human body

Conclusion –

Hope this article was deep enough for you to wet your feet in the vast ocean that is the study of human anatomy. Stay tuned for more such short 2 minute pre-MBBS reads and all the best for the NEET UG !