Unlike an electrical synapse, the chemical synapses are separated by a space called the synaptic cleft, typically measured between 15 and 25 nm. Transmission of an excitatory signal involves several steps outlined below.
Definition of cap. 1  1a : a head covering especially with a visor and no brimb : a distinctive head covering emblematic of a position or office: such as (1) : a cardinal's biretta (2) : mortarboard.
1. 'disc' or 'disk': a flat circular object. In British English, a disc is a flat circular object. A traffic warden pointed out that I had no tax disc on the windscreen. In American English, this word is spelled disk.