Astridestella.info: SIMPLE ANATOMY AND PHYSIOLOGY, THE DIGESTIVE SYSTEM

Digestion as I mentioned previously begins in the mouth, food is chewed up assisted by the teeth and tongue and mixed with saliva. Saliva helps moisten the food and helps us swallow it, but the enzymes within Saliva, amylase and pytalin break down carbohydrates, which are complex sugars into disaccharides. This chewed up food is now known as a bolus and is pushed down the oesophagus by the tongue. The oesophagus is a hollow muscular tube commonly known as the gullet. that leads to the stomach. The stomach is a muscular hollow organ that produces hydrochloric acid, to help break down food further and kill bacteria, it also produces Pepsin an enzyme to break down proteins. The stomach's muscular action churns up the food and it is now known as chyme as it passes into the first stage of the small intestine, the Duodenum, it is in the small intestine where the vast majority of digestion takes place.

The accessory digestive organs the pancreas and the liver now assist the process of digestion. The liver produces Bile, this is released and stored in the gallbladder and it is from there it is released into the duodenum its function is to emulsify fats and acts as a deodourant and gives faeces their brown colour. At the same time the pancreas produces digestive enzymes to further break down carbohydrates into simple sugars monosaccharides (amylase, lactase, sucrase) and (trypsin and chymotrypsin) break down proteins into polypeptides. Lipase breaks the fats down into fatty acids.

As the broken down food continues along the small intestine the lining is covered in small projections known as Villi, these increase the absorbent area and the nutrients from the food are absorbed through those into the blood stream. Obviously its a lot more complex than this as I'm trying to keep this simple.

The main function of the large intestine is to absorb water from the faeces and any remaining nutrients and the end result faeces is stored in the rectum until voided.

The Liver does have a very important role in the body besides manufacturing Bile as does the Pancreas and that will be explained in another blog.