The inside of the stomach with the beginning of the intestines. At 3 is the left end and at 4 is the right end. At 1 is the opening of the gullet into the stomach. At 5 is a valve (the pylorus) which is sometimes shut, so as to prevent anything from passing from the stomach into the intestines. 8 indicates the inside lining of the stomach which produces gastric juices. 6 shows the duct from the liver.