collections of nerve cell bodies outside the central nervous system are called ________.; nerve signals are transmitted by; how do nerve impulses travel across the synapse; any nerve cell that conducts a signal towards the spinal cord/brain is called; which part of the nerve cell receives information from other nerve cells?; how does an impulse travel from one neuron to another; how does the impulse travel within a neuron; a signal molecule that transmits nerve impulses across synapses