Intestinal nerves. Light micrograph of a section through the lining (mucosa) of the colon, showing a nerve ganglion. Functioning independent of external stimuli but also reactive to such signals, these ganglia number in the hundreds of thousands. They are interconnected by a complex network of nerve fibres forming the so-called myenteric or Auerbach's plexus. The plexus coordinates local gut muscle activity notably peristalsis. The plexus also regulates the functions of blood vessels and secretory activities of cells found in the epithelial lining of the gastrointestinal tract.