Facts of Digestive System

The digestive system has two main functions: to convert food into nutrients your body needs, and to rid the body of waste. To do its job, the system requires the cooperation of a number of different organs throughout the body, including the mouth, stomach, intestines, liver and  gallbladder.

Food doesn't need gravity to get to your stomach.

When you eat something, the food doesn't simply fall through your esophagus and into your stomach. The muscles in your esophagus constrict and relax in a wavelike manner called peristalsis, pushing the food down through the small canal and into the stomach.

Laundry detergents take cues from the digestive system.

The digestive system also employs these types of enzymes to break down food. Proteases break down proteins, amylases break down carbohydrates and lipases break down fats. For example, your saliva contains both amylases and lipases, and your stomach and small intestine use proteases.

Your stomach doesn't do most of the digestion.

Instead, the small intestine, which makes up about two-thirds of the length of the digestive tract, is where most of the digestion and absorption of nutrients takes place. After further breaking down the chyme with powerful enzymes, the small intestine absorbs the nutrients and passes them into the bloodstream.

The surface area of the small intestine is huge.

The small intestine is about 22 feet (7 meters) long, and about an inch (2.5 centimeters) in diameter. Based on these measurements, you'd expect the surface area of the small intestine to be about 6 square feet (0.6 square m) — but it's actually around 2,700 square feet (250 square m), or about the size of a tennis court.