Movement of a drug from the site of administration into the blood.

A neurotransmitter that enables muscle action, muscle memory, and muscle learning.

An enzyme that breaks down acetycholine when it enters the synaptic cleft.

Takes place when the membrane potential of a specific axon location rapidly rises and falls. This depolarization in turn causes adjacent axon locations to depolarize as well. Action potentials occur in several types of animal cells, called excitable cells, which include neurons, muscle cells, and endocrine cells.