The Structure, Function and Main Disorders of the Digestive System

Section 1: The Structure of the Digestive System

The digestive system consists of organs stretching from the mouth to the anus, and includes the esophagus, stomach, liver, gallbladder, pancreas, small intestine, colon (or large intestine), rectum and anus.
The accessory organs of digestion - the liver, gallbladder and pancreas - play vital roles in digestion but are not part of the digestive tract.
The small intestine consists of three parts: the duodenum, jejunum, and ileum.
The large intestine also consists of three parts: the ascending colon, the transverse colon, and the descending colon.

Section 2: Functions of the Digestive System

In the mouth, food is mechanically broken down and mixed with saliva, which begins the chemical digestion process.
The esophagus serves as a conduit, moving food from the mouth to the stomach through a process called peristalsis.
The stomach functions to break down food even further into a semi-liquid substance called chyme.
In the small intestine, most nutrients are absorbed into the bloodstream.
In the large intestine, water and electrolytes are reabsorbed, and remaining waste is formed into stools.

Section 3: Main Disorders of the Digestive System

Gastroesophageal Reflux Disease (GERD) is a chronic condition in which stomach acid regularly travels back up into the esophagus and sometimes into the mouth.
Gastritis is an inflammation of the stomach lining usually caused by infection, injury, alcohol consumption, or prolonged use of certain medications.
Colitis, or inflammation of the colon, comes in different types, with different causes and treatments.
Irritable Bowel Syndrome (IBS) is a common disorder affecting the large intestine, causing symptoms such as cramping, abdominal pain, bloating, gas, and diarrhea or constipation or both.
Crohn’s Disease is a type of Inflammatory Bowel Disease which may affect any part of the digestive tract but most commonly affects the end of the small intestine and the beginning of the colon. Symptoms include abdominal pain, diarrhea and often severe weight loss.
Gallstones are hard deposits in the gallbladder which can cause pain and potentially lead to infection or inflammation.
Pancreatitis is an inflammation of the pancreas, which can be acute or chronic, and is commonly linked to excessive alcohol consumption.
Hepatitis is an inflammation of the liver, often caused by viruses, but can be caused by alcohol or certain medications.

These are some examples of the more common disorders, there may be many other less common issues that inhabitants may experience.