Photo Gallery: Digestive System

Inside the Human Mouth

Photograph by Lennart Nilsson

Inside the mouth, shown magnified here, teeth, tongue, and saliva work together to physically and chemically break down food. Humans produce up to 3 pints (1.4 liters) of saliva daily, and chemical enzymes in the saliva play a major role in disintegrating starchy foods.

Man Eating a Burger

Photograph by Steve Niedorf Photography

A man prepares to eat his lunch, a hamburger. The digestive system helps break down complex meals into the constituent parts the body can use: carbohydrates, proteins, fats, vitamins, and minerals.

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Small Intestine Blood Vessels

Photograph by Susumu Nishinaga

This colored scanning micrograph shows a cast of blood vessels from the external wall of the small intestine. Measuring about 22 feet (6.7 meters) in length, the small intestine performs most of the major digestion and absorption of nutrients. The walls of the small intestine are lined with millions of projections called villi, which absorb and transmit nutrients into the bloodstream.

Digestive System

Illustration by PureStock

Once food is swallowed, it passes through the esophagus into the stomach, the pink organ shown here above the yellow pancreas. A large, muscular chamber, the stomach produces digestive juices like pepsin, lipase, and hydrochloric acid, which digest and dissolve stomach contents.

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Lower Digestive Organs

Image by Anatomical Travelogue/Science Photo Library

This image shows the lower digestive organs, including liver and stomach (enclosed by the rib cage) and the small and large intestines. After the small intestine absorbs food nutrients, leftover waste passes into the large intestine, where it's worked on by billions of harmless bacteria and mixed with dead cells to form solid feces. The feces are moved into the rectum to await expulsion.

Gastrostomy

Photograph by Barry Slaven

For the amounts of food it is constantly processing, the digestive system is an incredibly efficient machine, but problems can arise. Here, a surgeon performs a cyst gastrostomy, the removal of non-cancerous growths from the pancreas. The growths can form after a bout of pancreatitis.