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 funnel shaped mushroom that is tapered at the base. The cap of the mushroom usually measures up to six inches across, has a depressed center and a curly edge. When fresh, it has a bright yellow color, which fades to a paler yellow after it is harvested later in autumn and as it ages.