The correct answer to this question is esophagus. Although the muscle is, and the function sounds easy, it can have many disorders. One is called esophagitis, which occurs when the esophagus becomes inflamed. Allergies can cause this condition to food, infections, and reflux.
The esophagus is about 8 inches long. When food is swallowed, it leaves the esophagus and then enters the stomach. Once this is done, it continues to the digestive tract. The saliva in our mouths is added to food and makes it easier for it to pass through the tube. Saliva is also used to break the food down.