The gastrointestinal system is one long tube from the mouth down. After we ingest food, it is continuously broken down and digested through different chemical and physical processes. The accessory organs of the gastrointestinal system include the tongue, salivary glands, pancreas, liver and gallbladder. Here is a brief outline of the digestive process:
Figure 1: The Gastrointestinal System1
- Food enters the mouth, where the teeth and tongue help you chew it into small pieces. Here, saliva partially breaks down some food and helps us swallow it easily.
- The bolus (compacted ball of chewed food mixed with saliva) passes through the esophagus, a muscular tube about 25 cm in length.
- The esophagus empties into the stomach. Here, strong acids and enzymes chemically break down the food, while stomach muscles act like a blender to break it down even more. This produces a thick slurry known as chyme.
- Chyme from the stomach passes into the small intestine where most of the important molecules from the food are absorbed for our body to use. The small intestine is divided into three distinct segments: (1) the duodenum, (2) the jejunum and (3) the ileum.
- While in the duodenum, the chyme is exposed to bile (a greenish digestive fluid) secreted by the liver, as well as digestive fluids from the pancreas. These fluids help to further digest the chyme.
- The small intestine empties into the large intestine. Here, a lot of the water is reabsorbed and the material is processed by healthy gut bacteria which are important for digestion.
- Finally, the waste material is eliminated through the rectum and anus as feces.
If a gastric cancer diagnosis is made early enough, the disease is more likely to be considered curable. This assessment is made based on the stage of the tumor using the TNM system. Surgery for early gastric cancer tries to cure the disease by cutting out the organs affected by cancer cells. There are several different surgical options available to patients and their doctors. Some of the major ones are explained below.