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Nervous System Overview

Overview

Explore the complex networks that control every thought, movement, and sensation

Central vs Peripheral Nervous System

Central Nervous System (CNS)

Brain and spinal cord - your body's command center

  • • Processes sensory information
  • • Makes decisions and initiates responses
  • • Stores memories and coordinates learning

Peripheral Nervous System (PNS)

Nerves extending throughout the body - your communication network

  • • Connects CNS to limbs and organs
  • • Carries sensory signals to the brain
  • • Transmits motor commands to muscles
Animated brain diagram with labeled regions

Brain Regions

Cerebrum, cerebellum, brainstem - each with specialized functions

Spinal Cord

Information highway connecting brain to body

86 billion
Neurons in adult brain

Nerve Networks

Cranial and spinal nerves branching throughout body

Nervous System at a Glance

Major Components

Brain
Processing center for thoughts, emotions, and memories
Spinal Cord
Relays signals between brain and peripheral nerves
Peripheral Nerves
Connect every part of your body to the central system

Key Functions

Sensory Input
Gather information from environment and body
Integration
Process and interpret sensory information
Motor Output
Coordinate responses through muscle contractions and gland secretions
Neuron Structure

Neuron Structure

The building blocks of your nervous system

Animated labeled brain diagram

Parts of a Neuron

Dendrites

Tree-like branches that receive signals from other neurons

Cell Body (Soma)

Contains nucleus and maintains cell functions

Axon

Long fiber that transmits electrical impulses to other cells

Axon Terminals

End branches that release neurotransmitters to next neuron

Electrical Impulse (Action Potential)

1
Resting State
Neuron maintains -70mV potential
2
Stimulation
Threshold reached (-55mV)
3
Depolarization
Sodium channels open, +30mV reached
4
Repolarization
Potassium channels open, return to -70mV

Synapse & Neurotransmitters

Synaptic Cleft

20-40nm gap between neurons

Neurotransmitters

Chemical messengers like dopamine, serotonin

100 billion
Neurons in human brain
200-300
Miles per hour - speed of neural signals
100 trillion
Synaptic connections between neurons
Reflex Arc

Reflex Arc

Your body's lightning-fast response system

The Reflex Pathway

1

Stimulus

Hot surface touches skin

2

Receptor

Thermoreceptors detect temperature change

3

Sensory Neuron

Carries signal to spinal cord

4

Spinal Cord

Processes signal and initiates response

5

Motor Neuron

Carries response signal to muscles

6

Effector

Muscles contract, hand pulls away

Animated brain diagram

Real-Life Example: Touching a Hot Stove

Scenario

You accidentally touch a hot stove while cooking

Response Time

Reflex arc completes in ~0.5 seconds

Result

Hand jerks away before conscious awareness

Conscious Realization

Brain processes pain ~1 second after reflex action

0.1-0.5
Seconds for reflex response
3-10
Neurons involved in simple reflex
Brain-free
Response occurs before conscious processing

Applications

Technology meets the nervous system

Animated labeled brain diagram

Brain-Computer Interfaces

Cutting-edge technology that bridges human neural activity with computer systems, enabling mind-controlled devices and communication for paralyzed individuals.

Neural Prosthetics

Mind-controlled robotic arms using brain implants

Communication Aids

Thought-to-text systems for speech-impaired patients

Neurofeedback

Real-time brain activity monitoring for therapy

Medical Imaging

MRI, EEG, and fMRI technologies visualize brain activity in real-time

Neural Implants

Deep brain stimulation for Parkinson's and depression treatment

10,000+
Patients using BCIs worldwide

Current Impact

Restoring independence and improving quality of life

Technology Applications

Current Technologies

EEG Headsets

Non-invasive brain activity monitoring

Neural Dust

Wireless, battery-free neural sensors

Optogenetics

Light-controlled brain cells via genetics

Future Applications

Memory Enhancement

Brain implants to boost memory formation

Telepathic Communication

Direct brain-to-brain information transfer

Cognitive Augmentation

Enhanced problem-solving and learning abilities

Interactive Lab

Test your neural response and explore brain science hands-on

Reaction Time Test

Measure your neural processing speed with this simple test

Click to start test

Brain Anatomy Diagram

Explore the major regions of the human brain

Animated labeled brain diagram

Neuron Builder

Construct and test virtual neurons

Synapse Explorer

Watch neurotransmitters in action

Reflex Arc Simulator

Trace signals through neural pathways

Lab Equipment Showcase

EEG
Electroencephalography
fMRI
Functional MRI
PET
Positron Emission Tomography
HPLC
High-Performance Liquid Chromatography

Understanding Your Results

Fast Reflexes

Under 200ms indicates excellent neural processing

Average Range

200-300ms is typical for healthy adults

Practice Effects

Multiple attempts show improvement with training

Resources

Trusted sources and educational materials for deeper learning

Animated labeled brain diagram

Interactive Tools

Study Guides

  • IGCSE Biology

    Exam-focused revision materials

  • Brilliant.org

    Interactive problem-solving courses

  • Excellence in Science

    Advanced neuroscience concepts

Resource Categories

For Students

Beginner Level

Basic nervous system anatomy and function

Intermediate Level

Neural pathways and reflex mechanisms

Advanced Level

Neurotransmission and brain-computer interfaces

For Educators

Lesson Plans

Structured teaching materials and activities

Lab Exercises

Hands-on experiments and demonstrations

Assessment Tools

Tests and quizzes for knowledge evaluation