Glossary A

Atmospheric perspective refers to a depth cue. Objects that are farther away look more blurred and bluer than objects that are closer because we must look through more air and particles to see them.

Atom is a piece of an element that cannot be divided any further.

Atomic number refers to the number of protons in the nucleus of an atom

Atomic weight refers to the number indicating the weight of an atom relative to a weight of one for a proton

Atonia refers to lack of normal muscular tension or tonus

Atonic seizures refer to a kind of seizure which are characterized by a sudden loss of muscle tone and may result in a fall. They last no longer than 15 seconds while the person remains conscious.

ATP (Adenosine Triphosphate) refers to a compound that stores energy and is also used as a neuromodulator

ATP-PC system is a term used to describe the metabolic pathway involving muscle stores of ATP and the use of phosphocreatine to rephosphorylate ADP. This pathway is used at the onset of exercise and during short-term, high-intensity work.