Neurology - Neuro Keywords

Myelinated Nerve Fibers

Neurons that are wrapped in a protective, fatty, insulating layer called the myelin sheath that allows electrical fibers to travel more efficiently

Cerebrospinal Fluid

A clear, watery liquid that surrounds and cushions the brain and spinal cord

Diffusion

The passive movements of particles from and area of higher concentration to an area of lower concentration

Excitatory Input

A nerve signal that makes a postsynaptic neuron more likely to fire an electrical impulse (action potential)

Spatial Summation

Multiple signals arrive simultaneously

Temporal Summation

Signals arrive at different times

All or None Principle

A neuron or muscle will fire a maximum response to a stimulus or none at all

Propagation

The movement of an electrical nerve impulse along the length of an axon

Saltatory Conduction

The rapid way an electrical impulse or action potential “jumps” from one gap (node of ranvier) to the next along a myelinated axon.

Synaptic Cleft

A microscopic gap, typically 20-30 nanometers wide that separates a sending neuron from a receiving cell across which chemical messages travel

Stereognosis

The ability to identify an object placed in the hand by touch alone while your eyes are closed

Dermatomes

a specific area of the skin supplied by sensory nerve fibers from a single nerve fiber

Sensory homunculus

A map of the human body which shows how different body parts are processed by the primary somatosensory cortex

Exocytosis

An active transport process where a cell moves large molecules or waste out through it’s cell membrane

Decussate

Crosses over