Nervous System

Nerve Cells (Neurons)

Cells that transmit electrical and chemical signals.

Main Function of Nerve Cells

To transmit electrical and chemical signals throughout the nervous system.

Three Main Parts of a Neuron

Cell body, dendrites, and axon.

Cell Body

Contains the nucleus and other organelles.

Dendrites

Short, branching extensions that receive signals from other neurons.

Axon

A long, thin extension that transmits signals away from the cell body.

Three Main Types of Neurons

Sensory neurons, motor neurons, and interneurons.

Sensory Neurons

Receive signals from sensory receptors and transmit them to the brain or spinal cord.

Motor Neurons

Transmit signals from the brain or spinal cord to muscles or glands.

Interneurons

Connect sensory and motor neurons and process and integrate information.

Synapse

The junction between two neurons or between a neuron and a target cell.

Neurotransmitters

Chemicals released at the synapse that transmit signals from one neuron to another.

Action Potential

A rapid change in the electrical charge of a neuron that occurs when it is stimulated.

Function of an Action Potential

Triggers the release of neurotransmitters and the transmission of signals to other neurons.

Myelin

A fatty substance that surrounds and insulates the axons of some neurons.

Function of Myelin

Increases the speed and efficiency of signal transmission.

Plasticity

The ability of neurons to change and adapt in response to experience or injury.

Neuronal Plasticity

Allows the brain to reorganize itself and form new connections.