(Learn more about the organs of the human bodies in other posts in the Viscera series here: https://jineralknowledge.com/tag/viscera/?order=asc)
The stomach is an organ that is well-known, so much so that the abdomen is often colloquially referred to as “the stomach”. It is an important organ that is part of the digestive tract, responsible for breaking down food that comes in through the mouth then the oesophagus. The stomach lies centrally and just below the sternum, surrounded by the liver on the right, spleen on the left and pancreas below.
Food is broken down primarily by the mouth via chewing. Once you swallow, the food is squeezed through the oesophagus until it is dumped into the stomach. The stomach produces a very strong acid (hydrochloric acid, pH 1~2), which dissolves the chewed food. It enhances this process by contracting its powerful wall muscles to churn and mix the food. Once it is nicely dissolved into a thick liquid, it releases it into the duodenum (the first part of the small intestine).
If the stomach uses strong acid to breakdown food, which is organic matter, how come it does not digest itself? This is because the lining of the stomach is coated with a substance called mucin which protects the stomach wall from being corroded by acid. However, the stomach is not perfectly safe from the acid it produces. If the stomach becomes inflamed, the production of mucin and self-repair process of the stomach is limited and acid begins dissolving the stomach lining. This causes peptic ulcers to form, which is essentially a hole in the lining of the stomach, causing severe abdominal pain and occasionally bleeding. Peptic ulcers are commonly caused by an infection by a bacteria called Helicobacter pylori. It may also be caused by severe stress and anger or medications such as NSAIDs (non-steroidal anti-inflammatory drugs, e.g. ibuprofen, diclofenac/Voltaren).