In this section I am discussing the digestive system and gastrointestinal disorders, which covers a large area of what the physician encounters in everyday practice.
The digestive system (gastrointestinal tract) starts in the mouth and ends at the anal opening. Food travels from the mouth, where we chew it via the esophagus into the stomach. There acid and pepsin enzymes start digesting carbohydrates(sugar and starch) and the food travels into the small intestine, which consists of the three sections called duodenum, jejunum and ileum. At the ileocecal valve whatever is left from the food gets into the colon and finally the rectum. In the duodenum bile salts and pancreatic juices are added, which help to digest fat and protein. In the jejunum and ileum most of the nutrients and vitamins are absorbed including Vit. B12. The colon’s job is to reabsorb water, retain minerals and to prepare the left over, leached out material to become stool. The rectum is the last storage chamber and water is being re-absorbed from the stool, which is expelled as a bowel movement from time to time. The stool gets its final shape from the anal canal.
Three important organs are connected to the digestive system: the gall bladder, the pancreas and the liver. Gallbladder and pancreatic function have been mentioned above. The liver is the main metabolic organ of the body and receives nutrients via the veins from the small intestine, which form the portal vein system. Through this the liver gets all of the nutrients. Next the building blocks of fatty acids, amino acids and sugar molecules are taken by the liver and modified to fit the body’s needs. The blood vessels connect the liver to the rest of the body and in this way the nutrients can reach all of the body’s tissues. This is how the muscles can build up muscle mass, the brain gets glucose to think and all of the body cells maintain their metabolism.
In the following I will describe diseases of the digestive system and what can be done from a medical point of view to help cure or at least alleviate the conditions.