From the esophagus to the anus, the digestive is basically a tube very similar to other tubular organs in the body. All such tubular organs are composed of several tissue layers arranged around a lumen. In a "generic" tubular organ, these layers are as follows (from the lumen to the ablumenal layer).
the esophagus
stomach
Salavery glands
liver kidney and gall bladder
The alimentary canal is just the tube that goes from the mouth to the anus. The digestive system includes that tube but also all of the physiology that occurs along the tube and the accessory organs actions and products.
The pancreas, liver and the appendix however is not beneficial to the digestive system directly.
crap tunnel... no I'm just joking, its actually called the digestive system. You see there are so many different organs from mouth to anus that there is not one single name for it, but a system (group of organs working together for the same purpose).
Heart, brain, lungs.
Digestive System: You may be wondering that the organs in the digestive system are located in the abdominal cavity. True, but the esophagus, the tube that carries food to the stomach is located in the thoracic cavity. The thymus or thyroid gland is also a part of the organs in the pectoral cavity.Baxamusa, Batul Nafisa . "Organs in the Thoracic Cavity." Buzzle. Buzzle.com, n.d. Web. 4 Oct 2012. .
Digestive organs and the system in general can be divided into two parts: the accessory organs and the alimentary canal. The alimentary canal is the GI tract and the accessory organs are things like the teeth, tongue, salivary glands, and gallbladder.
The Esophagus
The digestive system is a series of hollow organs joined in a long, twisting tube from the mouth to the anus. Inside this tube is a lining called the mucosa. In the mouth, stomach, and small intestine, the mucosa contains tiny glands that produce juices to help digest food. Two solid organs, the liver and the pancreas, produce digestive juices that reach the intestine through small tubes. In addition, parts of other organ systems (for instance, nerves and blood) play a major role in the digestive system.
The liver and the pancreas are not called digestive organs because neither of them actually partake in digesting food. The liver actually stores glucose and turns it into energy when its needed and the pancreas creates insolin to control our sugar levels. So neither of them digest anything but they are called digestive because as I've just said they do partake in keeping our digestive system working properly from G.G