The stomach is an important organ of the digestive tract, involved in the second stage of digestion. The entry of the stomach is connected to the esophagus and the exit is connected to the duodenum (small intestine). At each end there is a sphincter, which allows entry and exit of food and fluids as well while keeping the contents contained as required. Most of us understand that the stomach has something to do with digesting our food, but let’s take a closer look at its function in the body.
What is the function of the stomach?
The basic role of the stomach is to process the food so that it is ready for absorption in the intestines. The stomach is the entry point for food and liquid after it is swallowed and passes through the esophagus. As soon as the chewed food, known as bolus, enters the stomach through the esophageal sphincter the stomach releases protein digesting enzymes and a strong acid, called hydrochloric acid. These enzymes begin breaking down the proteins into peptides and amino acids, which can be absorbed and used by the body. The strong acid has two important functions. Firstly, it kills or suppresses bacteria that enters with the food and it provides an acidic environment, which help the digestive enzymes to work.
At this point the stomach begins to churn the food with muscle contractions of the stomach wall (peristalsis). These processes convert the chewed food into the partially digested food, known as chyme, which then passes into the duodenum (small intestine). The stomach completes this process in about 40 minutes – 3 hours depending on the content and size of the meal.
The stomach does not play a large role in the absorption of food. In some cases, such as water when the body is dehydrated, Vitamin B12 or some medications, the stomach can absorb small molecules.
The stomach is also able to sense the nutritional value of food and helps the brain to link this value to the taste of the food!
Did you know?
Despite misconceptions that the stomach is located level with the belly button, it is actually located in the left side of the abdominal cavity level with the lowest ribs.