Introduction
Nerves are individual nerve cells which are a collection of neurons and part of our nervous system. These are located throughout our bodies under our skin, through and around our organs, and towards the centre area of the brain. Neurons are the cells that are present in the nervous system that transmits information to other nerve cells, muscles, or gland cells. The relation between neuron and nerve is nervous tissue is made up of different types of neurons that have an axon and an axon is the long stem-like part of the cell that transmits messages to the next cell.
Difference Between Nerve And Neuron Nerve :
It is a bundle of axons wrapped by the collective tissues.
It is covered by three layers perineurium, endoneurium, and epineurium.
These are found in the peripheral nervous system.
There are three types of nerves: afferent nerves, efferent nerves, and mixed nerves.
It is composed of many nerve fibers, blood vessels, and lymphatics.
Neuron :
It is an individual cell which is the functional unit of the nervous system
It has three major parts soma, dendrites and an axon
It is present in both the central and peripheral nervous system
There are three types of neurons motor neurons, sensory neurons and interneurons
It is composed of the axon, cell body, and dendrites
Nerve Cell Parts
Nerve cells are also called neurons. It consists of three parts which are as follows:
Cell Body - It contains the nucleus and other cell organelles. It is also known as (soma) the factory of the neuron. It provides and produces all the proteins for the dendrites, axons and synaptic terminals.
Dendrites - These are extended from the cell body and receive nerve impulses from other neurons. Dendrites are the antennae of the neuron and covered by a large number of synapses.
Axon - It is a long extension of the cell body that transmits nerve impulses to other cells. The branches of the axon at the terminal are known as axon terminals. At these terminals, neurons communicate with other cells. Myelin sheath is present in the axon of many neurons as an outer layer. It is a part of the motor neuron.
Working of the Neuron
The basic principle on which a neuron works is an electrically excitable cell that takes up processes and transmits information through electrical and chemical signals. With this, human beings can react to the environment as neurons transport stimuli. As all neurons are electrically excitable, the impulse mostly arrives at dendrites which are processed into the cell body and then move along the axon. Throughout the length of an axon, it functions as an electric cable by simply transmitting the signal. Once this impulse reaches the end of the axon means synapses a special molecule called a neurotransmitter is released by the neuron. This molecule stimulates the second neuron creating a new wave of electrical impulse. In the end, the impulse reaches the required part.
Different Types of Neurons in the Nervous System
There are basically three types of neurons which are as follows:
Sensory Neurons - These are the nerve cells that are activated by sensory input from the environment. Physical and chemical both inputs can activate sensory neurons that correspond to our five senses. Many sensory neurons have only one axon which is split into two branches called pseudounipolar.
Motor Neurons - These are present in the spinal cord part of the central nervous system which connects to muscles, glands, and organs throughout the body. The impulse from the spinal cord to skeletal and smooth muscles is transmitted through these neurons.
Interneurons - These are the ones that are present in between which connect the spinal motor and sensory neurons. These form circuits of various complexity while communicating signals between sensory and motor neurons.
Fun Facts
7 trillion nerves are there in the human body.
Neurons are of different shapes and sizes depending on their location.
The body at rest is controlled by the nervous system.
If all the nerves present in the body are lined up they would stretch for almost 45 miles.
Your nervous system is responsible for your ability to perceive your surroundings — to see, hear, and smell what's around you. In reality, your neurological system is responsible for your ability to wonder how you know where you are! Your capacity to know where you are and recall if you've been there previously also suffers.
Your nervous system has a role in your ability to act on information that suggests danger. In addition to allowing you to analyse the threat consciously, your nervous system activates instinctive responses to assist you in coping with danger, such as an increase in heart rate and blood flow to your muscles.
The connecting cells that make up your nervous system are essential to all of these functions. Like the heart, lungs, and stomach, the nervous system is made up of specialised cells. Nerve cells (or neurons) and glial cells are examples of this (or glia). Neurons are the nervous system's basic functional components, and they generate electrical signals called action potentials that allow them to send information over large distances quickly. Glia is also necessary for nervous system function. However, they primarily serve to sustain neurons.
Though nerve and neuron may sound identical, they are two distinct body parts that are closely related to one another. Nerves are genuine neuron projections.
A neuron is a single specialised cell that is responsible for conveying information via electrical and chemical impulses. They are found in the brain, spinal cord, and peripheral nerves. A nerve cell is another name for a neuron. Sensory neurons and motor neurons are the two types of neurons. A nerve is made up of several different types of neurons. In the peripheral nervous system, a nerve is an enclosed, cable-like bundle of axons and nerve fibres in the peripheral nervous system. Autonomic nerves, motor nerves, and sensory nerves are the three types of nerves.
FAQs on Neuron and Nerves
1. What are the classes of neurons?
The following are the several types of neurons:
Sensory neurons, motor neurons, and interneurons are the three types of neurons in the human nervous system, based on their functions. The following are the several types of neurons:
Sensory Neurons
Sensory neurons collect data about what is happening inside and outside the body and send it to the CNS for processing. When you touch hot burning coal, sensory neurons in your body with terminals present at your fingertips send information to the CNS about how hot the coal is.
Motor neurons
Motor neurons receive signals from other neurons and transmit them to your muscles, organs, and glands. Motor neurons innervating the muscles in your fingers, for example, would trigger your hand to let go if you picked up hot coal.
Interneurons
Interneurons are neuron-to-neuron connections found solely in the CNS. They receive and transfer information from other neurons (sensory neurons or interneurons) (either motor neurons or interneurons).
The signal from sensory neurons in your fingertips, for example, would travel to interneurons in your spinal cord if you picked up hot coal. Some of these interneurons signal the motor neurons that control the muscles of the fingers and encourage them to let go, while others climb the spinal cord and signal the neurons of the brain, causing pain.
2. What are the anatomy and functions of Neurons?
A neuron's anatomy
Neurons have a cell body, just like other cells (called the soma). The nucleus of the neuron is housed in the soma. Neurons require a high number of proteins, and the soma produces the majority of neuronal proteins.
The cell body is surrounded by several processes (appendages or protrusions). There are several short bifurcation processes known as dendrites and another process, usually known as axons, longer than dendrites.
A neuron's fundamental functions
You may draw the generalisation that all neurons have three basic functions if you consider the roles of the three kinds of neurons. The purpose of these is to: Receive signals (or information).
Assemble the incoming signal (to determine if you need to pass information).
Send signals to specific cells (e.g., other neurons, muscles, or glands).
The anatomy of the neuron reflects these neural functions.
3. What is a neuron system?
The nervous system, often known as the neural system, is a complex network of nerve cells or neurons. The neurological system is designed to transport messages, whereas the endocrine system uses hormones to offer chemical integration. The distinction between a neuron and a nerve is essential for a better understanding of the neurological system. Neurons are cells that have the ability to receive and transmit impulses, and they make up the nervous system's core. They are made up of three components and have a characteristic elongated shape:
Nerve cell body: Eukaryotic cell components include the nucleus, endomembrane system, and organelles.
Dendrites: They are tiny extensions of the nerve cell body that branch out at the receiving end of the neuron. They function as mini-antennas, picking up messages from neighbouring cells.
Axon: The axon is a long, thin fibre that extends from the body of the nerve cell. It branches out at the ends to form synaptic terminals indicated by swellings known as synaptic knobs. Many axons are surrounded by a fatty myelin sheath generated by Schwann cells. The nodes of Ranvier are tiny holes in the insulation found between the Schwann cells.
4. What is the difference between Nerve and Neurons?
The difference is-
Nerve
A nerve is a white fibre of neuron cells that carries impulses from the central nervous system to the effector organs and vice versa.
Only the peripheral nervous system has nerves.
A nerve is made up of a huge number of nerve fibres, as well as blood arteries and lymphatics.
The nerve serves as a signal-transporting conductor.
Nerves in the body include cranial nerves, spinal nerves, sensory nerves, and motor nerves.
Neuron
A neuron is a type of nerve cell that transmits nerve impulses.
Both the peripheral and central nervous systems contain neurons.
An axon, cell body, and dendrites make up a neuron.
In the neuron, chemical and electronic signals are produced.
There are three types of neurons in the body: sensory neurons, motor neurons, and interneurons.
5. How do neurons work?
When a neuron receives a huge number of inputs from other neurons, the signals accumulate until they reach a certain level.
The neuron is prompted to transmit an impulse along its axon when this threshold is exceeded, which is known as an action potential.
The transport of electrically charged atoms (ions) across the axon's membrane produces an action potential.
The membrane potential of neurons is more negatively charged than the fluid around them while they are at rest. Normally, it is -70 millivolts (mV).
When a nerve's cell body receives enough impulses to fire, a part of the axon closest to the cell body depolarizes — the membrane potential increases and then falls swiftly (in about 1,000th of a second). This causes depolarization in the part of the axon next to it, and so on, until the charge rises and falls along the full length of the axon.
Each section experiences a brief state of hyperpolarization after firing, in which its threshold is decreased, making it less likely to be activated again right away.
The action potential is usually generated by potassium (K+) and sodium (Na+) ions. Voltage-gated ion channels and pumps transport ions into and out of the axons.
6. What are the different types of nerves?
There are three different types of nerves:
Sensory Nerves - These nerves carry impulses to the sensory receptors towards the brain. These are also called afferent nerves. These nerves have the ability to sense or recognize the stimuli and carry sensory information toward the Central Nervous System.
Motor Nerves - These carry impulses away from the brain to muscles and glands. These are also called different nerves. These are usually located in CNS.
Autonomic Nerves - An involuntary or partially voluntary action of our body is controlled by these nerves. These nerves control the internal organs without any effort by the organism.
7. What are Central and Peripheral nervous systems?
Central Nervous System
This system controls most functions of the body and mind consisting of the brain and the spinal cord.
It is responsible for sending sensory information and responding accordingly.
The spinal cord in the body acts as a medium for signals between the brain and the rest of the body.
Peripheral Nervous System
This system refers to the parts outside the central nervous system, the brain, and the spinal cord.
In this system, bundles of nerve fibers or axons carry information to and from the nervous system.
This system is also classified into somatic and autonomic nervous systems.
