Did you know that the vagus nerve is one of the longest in your body, running from top to bottom (brain to rectum)? Its central purpose is to relay information from internal organs (such as those in your gastrointestinal system and heart) to the brain. The autonomous nervous system in your gastrointestinal system allows it to work independently of your the brain. While the average brain has nearly 100 billion neurons, the digestive system of the body (gut) has close to 500 million nerve cells and 100 million neurons. The heart-brain interaction takes place both by electrical signals (via the vagus and the spinal chord nerves) and through chemicals (heart is an endocrine gland also). Not only does the gut communicate with the brain chemically (e.g., releasing chemicals that are transported to the brain by the blood) but also by sending electrical signals via the vagus nerve.