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.
A typical baseball cap; this one is an Oakland Athletics cap. A baseball cap is a type of soft cap with a rounded crown and a stiff peak projecting in front. The front of the cap typically contains designs or logos of sports teams (namely baseball teams, or names of relevant companies, when used as a commercial marketing technique).