The Science

Brain Parts and Functions

How the Brain Works

What is Neuroplasticity?


Fun Facts

Neurons multiply at a rate 250,000 neurons/minute during early pregnancy.

The brain contains over 100 billion nerve cells, and each one has up to 10,000 synapses (connections to other cells), which equals around 1000 trillion connections in your brain.

The diameter of an individual brain neuron is just 4 microns thick. You could fit 30,000 neurons on the head of a pin.

How the Brain Works

Your brain is made of approximately 100 billion nerve cells, called neurons. All sensations, movements, thoughts, memories, and feelings are the result of signals that pass through these neurons. Neurons consist of three parts. The cell body contains the nucleus, where most of the molecules that the neuron needs to survive and function are manufactured. Small, branch-like projections called Dendrites extend out from the cell body and receive messages from other nerve cells. Signals then pass from the dendrites through the cell body and may travel away from the cell body down an axon to another neuron, a muscle cell, or cells in some other organ.

neuron diagram

When the signal reaches the end of the axon it stimulates tiny sacs, which release chemicals known as neurotransmitters into the synapse. The synapse is the place where a signal passes from the neuron to another cell. The neurotransmitters cross the synapse and attach to receptors on the neighboring cell. These receptors can change the properties of the receiving cell. If the receiving cell is also a neuron, the signal can continue the transmission to the next cell. Neural signals are transmitted along complex paths via a vast network of synaptic connections.

When you were born, your brain came with all the neurons it will ever have, but many of them were not connected to each other. When you learn things, the messages travel from one neuron to another, over and over. Eventually, the brain starts to create connections (or pathways) between the neurons. More activity creates stronger synaptic connections. Stronger connections support more efficient, flexible brain function, so things become easier and you can do them better and better. Learning literally shapes the brain. Every time we learn something, we change the structure of our brain a little bit, one synapse at a time.