Your Digestive System

The gastrointestinal (GI) tract, also known as the digestive system, is a series of organs responsible for the digestion and absorption of nutrients from the food we eat. It begins at the mouth and ends at the anus, and includes the esophagus, stomach, small intestine, large intestine, rectum, and anus.


Your Gastrointestinal (GI) Tract and How it Works Fine Health
Your Gastrointestinal Disease (GI) Tract and How it Works | Fine Health

 When we eat, food is mechanically broken down by chewing and mixed with saliva in the mouth. Saliva contains an enzyme called amylase, which begins the process of breaking down carbohydrates into simpler sugars. The chewed and partially digested food, now called a bolus, is then swallowed and passed down the esophagus to the stomach.

 

The stomach is a muscular sac that mixes and grinds the food, further breaking it down into a liquid called chyme. The stomach also secretes gastric juice, which contains hydrochloric acid and the enzyme pepsin. These substances help to kill bacteria, activate other digestive enzymes, and continue the process of breaking down proteins into smaller peptides and amino acids.

 

From the stomach, chyme moves into the small intestine. The small intestine is a long, narrow tube that is coiled like a hose. It is divided into three sections: the duodenum, jejunum, and ileum. The walls of the small intestine are lined with tiny finger-like projections called villi, which greatly increase the surface area for absorption. The small intestine also receives digestive enzymes and bile from the pancreas and liver, which help to break down fats, carbohydrates, and proteins into their simplest forms.

 

As the chyme moves through the small intestine, the nutrients are absorbed through the walls of the intestine and into the bloodstream. The remaining undigested food and waste products pass into the large intestine.

 

The large intestine is a wider tube that absorbs water and electrolytes from the remaining undigested material, forming feces. The feces are then stored in the rectum until they are expelled through the anus during defecation.

 

The entire process of digestion and absorption is regulated by the nervous system and hormones produced by the GI tract and other organs. For example, the hormone gastrin stimulates the production of gastric juice, while the hormone cholecystokinin stimulates the release of bile from the liver and the secretion of pancreatic enzymes.

 

Proper functioning of the GI tract is essential for good health. Dysfunction can lead to a variety of digestive disorders, such as constipation, diarrhea, acid reflux, and inflammatory bowel disease. Maintaining a healthy diet, drinking plenty of fluids, and engaging in regular physical activity can help to keep the GI tract functioning properly.