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Nerves and the Nervous System – The Operating System of Human Beings

Let’s say a bee lands on your hand. A message from the nerves in your hand races to your brain –“There’s a bee on my hand.” Your brain quickly processes the information and responds with the message, “Danger. Move your hand. The bee might sting you.” You shake your hand and the bee flies away. Crisis averted.

Nerve Facts For Kids

  • Nerves send messages fast!
  • They are like tiny wires.
  • You have 3 types of nerves.
  • Some nerves are very long.
  • Nerves work with your brain.
  • They help you feel things.
  • Nerves tell muscles to move.
  • Your skin has many nerves.
  • Nerves can repair slowly.
  • They carry signals as electric pulses.

Neuron Structure

Nerve cells, or neurons, are uniquely structured to fulfill their essential function in our bodies. The three primary components of a neuron are the cell body, or soma, dendrites, and an axon. The cell body serves as the neuron’s command center, housing the nucleus that contains the neuron’s DNA.

Dendrites, resembling branches, receive and relay messages from other nerve cells to the cell body. Conversely, the axon, a long, tail-like structure, dispatches messages from the cell body to other neurons or muscles.

This specialized structure of neurons facilitates the efficient reception, processing, and transmission of information, empowering us with the ability to think, feel, move, and even dream.

Synapse Function

Synapses, tiny gaps between nerve cells, play a crucial role in our nervous system, acting as transfer points for information from one neuron to another.

This transmission process begins when a signal triggers a neuron to release neurotransmitters, chemicals that cross the synapse and bind to the next neuron, thereby prompting it to continue the signal along the pathway.

This sequence of events enables our brains to dispatch messages to various parts of our body, facilitating our ability to think, move, feel, and learn. Thus, synapses essentially serve as a busy post office for our nerve cells, guaranteeing the successful delivery of every vital message.

Axonal Transport

Axonal transport is an incredible process that takes place within our nerves, acting as the mail delivery system of our body’s nervous system. It involves our nerve cells, also known as neurons, which possess long extensions known as axons.

These axons function like bustling highways, enabling the transportation of materials such as nutrients, waste products, and other essential substances. This process is facilitated by motor proteins that operate like trucks, carrying diverse cargo necessary to maintain the health and functionality of the neuron.

It’s truly remarkable how such intricate systems operate even at the smallest levels within our bodies.

Myelin Sheath

The Myelin Sheath, the integral part of our nervous system, functions like a protective layer akin to the plastic coating on electronic wires, encapsulating the axon – the component of the nerve responsible for transmitting messages.

Comprising a fatty substance called myelin, this sheath furthers the speed and efficiency of signal transmission along the nerve. Without it, the rapidity and potency of message transference would be compromised, impeding our abilities to perform basic functions such as movement, sensation, and cognition.

Reflex Arc

Reflex arcs, a captivating element of our nervous system that children may find intriguing, serve as ultra-rapid communication channels our bodies use to react to stimuli before our brain comprehends the event. An example of its use is when we come into contact with a hot object, the reflex arc is responsible for our immediate hand withdrawal.

The process begins with sensory nerve cells in our skin alerting our spinal cord about the high temperature. Instantaneously, the spinal cord dispatches a response back to our hand, instructing it to retract.

Remarkably, this entire sequence of events unfolds in a split second, even before our brain registers the hot sensation, demonstrating the impressive speed and efficiency of our body’s reflex arc.

Peripheral Nervous System

The peripheral nervous system, a crucial subsystem of our body’s overall nervous system, operates outside the confines of the brain and spinal cord.

This system bridges the gap between the central nervous system and the limbs and organs, facilitating the brain’s communication with the rest of the body. For instance, if you encounter a hot object, it’s the peripheral nervous system that promptly relays the ‘hot’ sensation to the brain, which then instructs your hand to retract.

This rapid communication is due to the incredible velocity at which nerves transmit these messages. Comprising millions of nerve cells, the peripheral nervous system equips our bodies with the ability to sense, move, and respond to our environment.

Sensory Receptors

Sensory receptors, intriguing components of our nervous system, enable us to engage with our environment. These specialized nerve endings, distributed throughout our body including areas such as our skin, eyes, ears, nose, and tongue, are accountable for recognizing various forms of stimuli such as heat, light, sound, smell, taste, and pressure.

Once a stimulus is detected, these receptors transmit signals via our nerves to our brain, which deciphers these signals, consequently enabling us to comprehend our world. Sensory receptors in our eyes, for instance, make it possible for us to discern colors and shapes, while those in our nose facilitate our ability to detect various fragrances.

Thus, every sensation we experience, from tasting our preferred food to feeling the sun’s warmth on our skin, is a testament to the diligent functioning of our sensory receptors.

Action Potential

The concept of Action Potential is fundamental to understanding the functioning of our nervous system, acting as a miniature electric wave coursing through our nerves. It kicks into action when we make a decision to perform a physical movement such as blinking or lifting an arm.

This triggers our brain to dispatch a command in the form of an action potential. This electric impulse then zips through our nerves to the designated body part, instigating the desired movement. This intricate process operates as an ultra-rapid internal messaging system within our body. Astoundingly, this entire sequence transpires so swiftly that it appears to occur instantaneously.

Neuroglia

Neuroglia, also commonly referred to as glial cells, form a crucial and intriguing aspect of our nervous system that may captivate children’s curiosity. Despite their less renowned status compared to neurons, their role is of utmost significance.

They function as a supporting cast for neurons, the brain cells responsible for conveying messages throughout our bodies, by safeguarding, nourishing, and ensuring their optimal performance. Interestingly, neuroglia outnumber neurons in our brain, constituting about half of the total brain cells.

Without the indispensable neuroglia, neurons would fall short of executing their duties accurately. Therefore, while neurons may enjoy the spotlight, the real unsung heroes working tirelessly behind the scenes in our nervous system are the neuroglia.

Autonomic Nervous System

The Autonomic Nervous System (ANS), an extraordinary segment of our nervous system, operates autonomously and regulates vital functions such as heart rate, digestion, respiratory rate, and perspiration, all without conscious thought. It’s comprised of two components, the sympathetic and parasympathetic systems.

The former is responsible for heightened physiological responses when encountering danger or excitement, such as elevated heart rate and breathing. Conversely, the parasympathetic system fosters relaxation and aids in food digestion.

Thus, irrespective of partaking in strenuous activities like racing or indulging in a meal, the ANS is persistently performing its duties.

main Parts of the Central Nervous System Image - Science for Kids All About Your Nerves
The nervous system and its main parts.

All of this happens in less than two seconds. In fact, messages from your body can zip to your brain at a speed of 200 mph. Your nervous system is the communications center for your body. Your brain is the central control panel. Here, billions of neurons receive electrical impulses from nerves in your body. The nerves can alert your brain to danger or pain.

Fun Facts about the Nervous System for Kids

  • Your central nervous system includes your brain and your spinal cord. Your spinal cord is a long bundle of neurons that goes down your back. From the spinal cord, nerves stretch throughout your body like a highway. This is the peripheral nervous system.
  • If you touch a hot stove, impulses from your brain go to your brain. Your brain sends back a message telling you to move your hand so you don’t get hurt.
  • The hypothalamus controls body temperature, thirst and other bodily functions. If you get too cold, your brain sends a message to your body to shiver, which helps warm you up.
  • Your hypothalamus even controls when you get a fever. When germs invade your body, chemical messages are sent to the brain. Your brain tells white blood cells to start working harder to fight off the bacteria. This extra work makes your body warm up. A fever means the white blood cells are defending your body from the invaders.
Explanation of the Spinal Reflex Image
All about your nerves and how your nervous system reacts to danger.

Nervous System Vocabulary

  1. Crisis: dangerous situation
  2. Avert: prevent
  3. Neurons: cells in the nervous system
  4. Impulses: messages
  5. Bacteria: germs that can make you sick
Tired Man Image
The hypothalamus controls body temperature, thirst and other bodily functions.

Learn More All About Your Nerves and the Human Nervous System

Watch this video all about your nerves at work:

A video about the human nervous system and how it functions.

Nervous System Q&A

Question: How big is the nervous system?

Answer: Your brain weighs about 3 pounds. The spinal cord is 18 inches long and is about ¾ inch thick. Nerves run throughout your body.

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Question: Can my nervous system be damaged?

Answer: Your brain and spinal cord are protected by bone, fluid and special membranes. But, they can be permanently damaged by accidents or illness. Always wear a helmet when you’re riding a bike or skateboarding and wear a seatbelt in the car. These things can help keep your precious control panel safe.