Your stomach is often thought to be near your belly button but your stomach actually sits higher up in your torso than you might think (See below).
Your stomach has a remarkable ability to expand. At its smallest it is about 75 millilitres in volume, less than a can of pop, while at its largest it can hold up to 1 litre of food.
The stomachs function is to hold food that you’ve eaten and to mix this food with hydrochloric acid and a digestive enzyme called Pepsin. This mixture is called Chyme.
- The hydrochloric acid acts to kill bacteria in the food and to activate Pepsin.
- Pepsin is an enzyme that begins the digestion of proteins. Pepsin breaks down all proteins regardless of their origin so it is important to only turn it on when there is food present, otherwise it would damage the stomach.
- The stomach also secretes mucus to coat itself and protect it from the acid and Pepsin.
Digestion and storage are not your stomachs only roles. It releases hormones that control the release of other digestive molecules including bile. It can also sense the types of molecules in the chyme and modify the amount of digestive juices each organ releases to best digest the food.
While the absorption of most nutrients occurs in the small intestine, the stomach is important in absorbing a couple key compounds including: Aspirin and other medications, Caffeine, and water during dehydration.
One of the most important functions of the stomach is to produce a protein called Intrinsic Factor. This protein is essential for your body to absorb vitamin B12 in the small intestine. Without enough vitamin B12 you can suffer problems with brain function like depression, fatigue, poor memory and even psychosis at severe deficiencies.