neuron

Neuron

Specialized nerve cell that is the functional unit of the nervous system.

Neural signalling

Communication via neurons, allowing organisms to receive and respond to stimuli.

Afferent neurons

Transmit stimuli collected by sensory receptors to interneurons; also known as sensory neurons.

Interneurons

Collect information and formulate a response; primarily found in the brain and spinal cord.

Efferent neurons

Carry responses from interneurons to effectors, such as muscles and glands.

Reflex Arc

A neural circuit that travels through the spinal cord but does not require the coordination of the brain.

Synapse

Connections between neurons or between neurons and effectors.

Chemical Synapse

A synapse in which a neurotransmitter moves from a presynaptic cell to a postsynaptic cell across the synaptic cleft.

Neurotransmitter (NT)

A chemical released from vesicles into the synapse to facilitate nerve signal transmission.

Resting Membrane Potential

The voltage difference across a nerve cell membrane of an unstimulated neuron, typically around -70 mV.

Action Potential

The voltage difference across a nerve cell membrane when the nerve is excited.

Membrane Potential

The electrical potential of a membrane caused by an imbalance of charges on either side of the membrane.

Excitable Cells

Cells that respond to stimuli causing their membrane potential to change rapidly.

Schwann cells

Cells that form tightly wrapped layers of plasma membrane to create myelin sheaths.

Nodes of Ranvier

Gaps between Schwann cells that expose the axon membrane to extracellular fluid for rapid conduction of nerve impulses.

Integration

The sorting and interpreting of messages and determining a response in the nervous system.