The nerves of a species are known as a system that carries electrochemical properties. These properties help an animal including human beings to sense something using their five sense organs. This system is formed by the conjunction of nerve fibres consisting of neurons. They are connected to every part of a body by connective tissues. It originates from the brain stem that expands into all the parts of a body through the spinal cord present inside the vertebral column.
The nerves are a constituent of several neurons joining together to operate as a system that carries impulses. These impulses are produced by a surge of electrochemical solutions to operate three types of nerves. One of them is the sensory nerves, which help all the sense organs to get their messages. On the basis of this structure, motor nerves send signals to the muscles in the body. The final form is a mixed nerve made from both sensory and motor nerves.
Figure 1: Neuron
The structure of nerves is a complex network of cords made by a large number of nerve fibres. These nerve fibres are termed axons, which make the trunk of a single nerve cell. Now starting from the very top, the dendrite has the job of increasing the surface area of the cell body. The second part of this structure known as the soma makes neurotransmitters. These are the pulses that act as a surge to make different bodies respond to the messages. The nucleus of this cell is located at the centre of soma where it regulates the gene structure of the cell. The cord-like structure extends beneath the head of this cell to make axons whose work is to act as a bridge. This is how they transmit the electrochemical impulses to a different neuron. The next part of this structure is known as the node of Ranvier which conducts the impulse in a fraction of seconds.
The second last part of the structure is called the axon terminal which marks the end of this axon present in a single nerve cell. It carries the presynaptic impulses over to the next nerve cell. Thus, it is marking the end of a particular nerve cell with Schwann cell and myelin sheath. The work of these two parts of the structure is to maintain the Peripheral Nervous System (PNS) and, the sheath allows efficient transmissions of nerve cells without a delay.
There are three types of nerves present in a body that belongs to any species in animal kingdom. These are the Sensory nerves, motor nerves and mixed nerves.
Sensory Nerves play the role of carrying messages from the brain to all the sense organs in a body. These are enclosed in the form of a bundle like structures or nerve fibres in the peripheral nervous system.
Motor Nerves are those nerves that carry the messages in the form of a response from the brain or the spinal cord to other parts of the body such as muscles and glands.
Mixed Nerves are the nerves that performs both the action of sensory nerves as well as motor nerves. They transform electrical impulses from the central nerves system to the muscles of the body.
Figure 2: Central Nervous System
The major functions of a nervous system are mentioned below in four different points
The primary function of the nervous system is to receive the signals and sent to the brain. This function is known as the sensory reception of signals after someone touches something.
The secondary function is to get the best of special signals apart from simple touching, this signal mainly revolves around the sight, taste and smell of something.
The brain is where all the signals are sent by the nerves to get orders for daily activities. Hence apart from carrying the signals, they help the brain to process them.
The last role of this system is to respond to the orders and execute it.
The most famous disease affecting the nervous system of a human being is Alzheimer’s disease. Here the patient cannot remember any memory of their distant past.
The second disease of this system is cerebral palsy, which hampers the motor nerves. In this case, the victim is born with this disease therefore; it becomes hard for them to maintain balance and posture while doing daily activities.
There are many other diseases affecting the system but it is possible to cure them in various ways. The only condition is to diagnose the disease at an early stage for the treatment to take an effect.
The tutorial explains all basic aspects of the nervous system in a human or an animal. The section includes all the differences in the structure of the nerve cell. The second part of the tutorial explores all functions carried out by different types of nerves. The final part sheds light on some of the major disorders affecting the functioning of a healthy nervous system.
Q1. What happens when a nerve cell suffers some serious injuries?
Ans. The nerve cells never respond to pressure or any kind of pain after it suffers a major injury. This takes about a few months to regenerate into a new cell.
Q2. What happens to the nerve cells in the brain after a patient suffers a cerebral attack?
Ans. The nerve cell of a human or any other brain does not regenerate after someone suffers from a cerebral attack. They stay damaged until the patient draws their last breath.
Q3. What is produced by soma?
Ans. Neurotransmitters and electrochemical substances carrying impulses are produced by soma.
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