The ensuing voltage drop caused more voltage-gated ion channels to pop open, allowing more ions to rush inside the cell, causing more of the membrane to short-circuit. The long cable of the nerve, the axon, is lined with these voltage-gated channels, so once the short-circuiting was kicked off at the cell body, it triggered a kind of domino effect of membrane short-circuiting—the action potential—that quickly traveled down the nerve until it reached the nerve ending (figure 8.3).
