Digestive System Overview Quiz

The Digestive System: From Mouth to Anus

The digestive system is a complex, interconnected network of organs that work together to break down food and absorb nutrients, providing energy and essential components to every cell in the body. The system is divided into two main parts: the gastrointestinal (GI) tract and the biliary system.

Gastrointestinal (GI) Tract

The GI tract is a series of hollow organs that are connected from the mouth to the anus. It includes the following organs in the order they are connected:

1. Mouth: Digestion starts here with the teeth grinding up food and saliva moistening it. Saliva contains an enzyme that starts breaking down carbohydrates into sugars.
2. Esophagus: Once swallowed, muscular contractions massage the food down into the stomach.
3. Stomach: The food passes through a sphincter into the stomach, where it is mixed with gastric juices and churned to break down food mechanically and chemically.
4. Small Intestine: The partially digested food enters the small intestine, where it is mixed with more digestive enzymes from the pancreas and bile from the liver. Nutrients are absorbed through the ileum, which is lined with finger-like projections called villi.
5. Large Intestine: Once all the nutrients have been absorbed, the waste is moved into the large intestine. Water is removed, and the waste forms stool, which is stored in the rectum and eventually excreted through the anus.

Biliary System

The biliary system is a network of three organs that deliver bile and enzymes through to the GI tract:

1. Liver: The liver breaks down fats using bile stored in the gallbladder, processes proteins and carbohydrates, filters and processes impurities, drugs, and toxins, and generates glucose for short-term energy needs from other compounds.
2. Pancreas: This gland secretes digestive juices and a hormone called insulin, which helps regulate blood sugar levels.
3. Bile Ducts: These ducts transport bile from the liver and gallbladder to the small intestine to aid in the digestion of fats.

The digestive system is a vital part of our body, providing the nutrients and energy we need to function properly. Problems can arise in various parts of the system, such as inflammation of the bowel (colitis), inflammation of pouches lining the small intestine (diverticulitis), infections causing vomiting and diarrhea (gastroenteritis), heartburn (when stomach contents back up into the esophagus), and ulcers (holes in the mucous membrane lining the stomach or duodenum).