Unit 1.3.A: The Neuron and Neural Firing - Structures and Functions

Neurons

The basic building blocks of the nervous system.
They are cells that send and receive messages in the body.

Glial cells

The “helper” cells that support, protect, and nourish neurons.
They don’t send messages, but neurons couldn’t work without them.

Reflex arc

A fast, automatic response that doesn’t require the brain right away.
The signal goes: sensory neuron → interneuron (in spinal cord) → motor neuron.

Sensory neurons

Neurons that carry information from your senses to the brain/spinal cord.
(Example: “My hand touched something hot!”)

Interneurons

Neurons in the brain and spinal cord that connect sensory and motor neurons.
They help the body process information and decide what to do.

Motor neurons

Neurons that carry messages from the brain/spinal cord to your muscles.
(Example: “Move your hand away!”)