The Nervous System

Studying the nervous system . I understand the functions of the nervous system . I understand that the sensory imput sends information to the CNS then it's integrated , then the imformation leaves and goes to the motor output , and commands a response .I've learned that the CNS consists of the  brain and spinal cord ,and the PNS is  outside the central  nervous system . There are two sets of nerves in the PNS ; the sensory division which is afferent ,meaning going towards the center , and the motor which is eferrent which means moving away out the muscles . I 've also learned that the PNS has two parts ; the somatic which is found in the skeletal is voluntary , and the autonomic  found in cardic muscle , smooth muscle , and the glands is in voluntary . What I'm having problems undestanding is the concept of measuring resting membrane potential . I realize that potential energy is stored energy , and that electrons are charged particles, that flows throughs  our cells to induce movement , but then it's kinda fuzzy the whole concept of the resting membrane potential . I plan to read my text ,and Google some  of the concepts in Chapter 11, to get a bettter understanding .