The document summarizes key aspects of the vertebrate nervous system including: 1. It describes the two main cell types - neurons and neuroglia. Neurons transmit signals while neuroglia nourish and protect neurons. 2. It outlines the structure of neurons including dendrites, cell body, axon and terminal. It also describes different types of neurons. 3. It provides an overview of the electrical signals in neurons including action potentials and graded potentials and how they are used to communicate signals short and long distances.