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Human Nervous System

        The Human Nervous System is made up of a complex network of specialised nerve cells known as neurons. Neurons
        are the  building blocks of the nervous system and are responsible for communicating messages throughout the
        body. At birth, the human brain consists of an estimated 100 billion neurons. Each firing off 5–50 messages or
        signals per second. If you touch something hot, that information goes from your fingertips to your brain, and then
        your brain says “move your hand away otherwise it will burn!” and sends information to your fingertips telling
        them to move away.
        A neuron is made up of a cell body, an axon and dendrites. The cell body has genetic information, maintains the
        neuron’s structure, and provides energy during the transmission of signals.
         An axon is an elongated structure which joins the cell body. Dendrites are fibrous roots that branch out from the cell
        body.
        There are three types of neurons in our body:
           • Sensory neuron: It carries the sensory signals from sensory organs to the brain. It gets activated when you
          touch, smell, hear, see or feel something.
           • Motor Neuron: It carries the signal from the brain or spinal cord to the organs, glands or muscles to carry out
          voluntary or involuntary movement.
           • Interneuron: They connect the sensory and motor neurons to help in the transmission of signals and form a
          complex internal neuron network.
        During the transmission, the nerve impulse travels in the form of electrical signals from the axon of one neuron
        to another neuron through a joint called synapse. The dendrites of another neuron receives an impulse which
        travels through the cell body and performs an activation function on the impulse received and then gives it to
        the output axon which passes the same to the next neuron in the system.



                                                                          Dendrites


                                        Soma
                                                                             Nucleus



                                                                         Axon hillock

                                                                         Myelin sheath

                                         Schwann cell
                                                                         Node of ranvier





                                        Terminal
                                        button



                                                     A nerve cell (neuron)


                 Relation between the Neural Network and Nervous System

        Just like the human brain where all neurons are interconnected to one another, artificial neural networks also
        have a large number of artificial neurons(nodes) that are interconnected to one another in a sequence of layers
        of the networks.

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