Using advanced technology to create images of the living, healthy brain. Computerized axial tomography (ct or cat scan) Allows us to watch the brain in action. Neurons - cells in the nervous system that communicate with one another to perform information-processing tasks. About 86 billion neurons in the brain. Glia - cells that also help support neurons. Astroglia - create the blood-brain barrier regulate flow of blood into different brain regions. Oligodendroglia - provide myelin in the brain and spinal cord to speed up transmission of neurons. Microglia - clean up dead cells and defend against infection in the brain. Neurons vary in size and shape, depending on their location and function. Allow different neurons to connect to one another. Dendrites - receive information from other neurons and sensory receptors. Cell body - receives information from dendrites, and if enough simulation is received the message is passed on to the cortex.