Medical Students

A neuron is the fundamental building block of the nervous system. Think of it as a specialized "messenger" cell designed to transmit information throughout your body using electrical impulses and chemical signals.
Unlike most cells, neurons don't just sit there—they are part of a massive, high-speed biological circuit that controls everything from your heartbeat to your deepest thoughts.
Anatomy of a Neuron
To understand how they work, it helps to look at their unique structure, which is built specifically for communication.
* Dendrites: These are the "antennae." They receive incoming signals from other neurons and carry them toward the cell body.
* Soma (Cell Body): The command center. It contains the nucleus and maintains the cell’s health and function.
* Axon: A long, tail-like cable that carries the electrical impulse away from the cell body toward other neurons or muscles.
* Myelin Sheath: An insulating layer of fat wrapped around the axon. It acts like the rubber coating on a wire, allowing signals to travel much faster.
* Axon Terminals: The exit points. This is where the electrical signal is converted into a chemical message to jump to the next cell.
How They Communicate
The magic happens at the synapse, the tiny gap between two neurons.
* Electrical Phase: An electrical pulse called an action potential travels down the axon.
* Chemical Phase: When the pulse hits the terminals, it triggers the release of neurotransmitters (like dopamine or serotonin).
* The Jump: These chemicals float across the synapse and "unlock" receptors on the next neuron, starting the process all over again.
Fun Fact: Speed and Scale
* Speed: Nerve impulses can travel at speeds of up to 120 meters per second (about 270 mph).
* Quantity: Your brain contains roughly 86 billion neurons, forming trillions of connections. If you lined them up, they’d stretch for miles!