Site Glossary

One thousandth of a micrometre.

a naturally occurring satellite, such as a moon.

A giant cloud of gas and dust where new stars are born.

Acceleration in the chosen negative direction.

A feedback mechanism that reverses a change and returns conditions toward normal.

Motion in the direction opposite to the chosen positive direction.

A microscopic functional unit of the kidney.

An electrical signal that travels along a neuron.

The organ system that controls and coordinates body activities using electrical signals.

Tissue that transmits electrical signals throughout the body.