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digestion
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References & Edit History Quick Facts & Related Topics
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human digestive system
The chemistry of digestion: How food is broken down
Why do people feel full after a big meal?
Digestive vacuole
Why can coffee act as a laxative?
Why does your stomach make noise?
The small and large intestines animated
Major organs of the human digestive system. Food taken in by the mouth is guided by the tongue as it is sheared and ground by the teeth. The bolus of chewed food is moistened and lubricated with saliva secreted by the salivary glands. Enzymes in the saliva begin the breakdown of starches. The epiglottis, a flap of tissue, prevents food from the pharynx from entering the larynx during swallowing. Muscles in the esophagus wall contract in waves to move the food to the stomach. Gastric juices secreted by the stomach contain a mixture of substances (including enzymes and hydrochloric acid) that break down the food into a semiliquid mass called chyme. The chyme passes into the small intestine, where food molecules are broken down into sugars, amino acids, and fatty acids. These useful substances are absorbed into the bloodstream as the food passes through the duodenum, jejunum, and ileum. The pancreas secretes digestive enzymes into the duodenum. The liver secretes bile salts that make insoluble fats entering the small intestine water-soluble and vulnerable to enzymatic action. Excess bile salts are stored in the gallbladder. The large intestine (colon) serves to remove water and electrolytes from the digested chyme and to compact and store undigestible material, called feces. Fecal matter is moved by muscular contractions into the rectum and expelled from the anus.
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digestion: Facts & Related Content

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Facts

Also Known As digestive process

Photos and Videos

human digestive system
Digestive vacuole
Major organs of the human digestive system. Food taken in by the mouth is guided by the tongue as it is sheared and ground by the teeth. The bolus of chewed food is moistened and lubricated with saliva secreted by the salivary glands. Enzymes in the saliva begin the breakdown of starches. The epiglottis, a flap of tissue, prevents food from the pharynx from entering the larynx during swallowing. Muscles in the esophagus wall contract in waves to move the food to the stomach. Gastric juices secreted by the stomach contain a mixture of substances (including enzymes and hydrochloric acid) that break down the food into a semiliquid mass called chyme. The chyme passes into the small intestine, where food molecules are broken down into sugars, amino acids, and fatty acids. These useful substances are absorbed into the bloodstream as the food passes through the duodenum, jejunum, and ileum. The pancreas secretes digestive enzymes into the duodenum. The liver secretes bile salts that make insoluble fats entering the small intestine water-soluble and vulnerable to enzymatic action. Excess bile salts are stored in the gallbladder. The large intestine (colon) serves to remove water and electrolytes from the digested chyme and to compact and store undigestible material, called feces. Fecal matter is moved by muscular contractions into the rectum and expelled from the anus.
The chemistry of digestion: How food is broken down
Why do people feel full after a big meal?
Why can coffee act as a laxative?
Why does your stomach make noise?
The small and large intestines animated
See All Videos and Images →

Related Topics and References

Topics
Dig Deeper: More Articles That Discuss This Topic

Key People

Claude Bernard, detail of a lithograph by A. Laemlein, 1858
Claude Bernard
French scientist
Helmont, Jan Baptista van
Jan Baptista van Helmont
Belgian scientist
Starling
Ernest Henry Starling
British physiologist
Sir William Maddock Bayliss
British physiologist
William Beaumont
United States army surgeon

Related Quizzes and Features

Quiz
Male muscle, man flexing arm, bicep curl.
Facts You Should Know: The Human Body Quiz
Male muscle, man flexing arm, bicep curl.
Facts You Should Know: The Human Body Quiz
Muscles of facial expression, human anatomy, (Netter replacement project - SSC). Human face, human head.
Characteristics of the Human Body
greylag. Flock of Greylag geese during their winter migration at Bosque del Apache National Refugee, New Mexico. greylag goose (Anser anser)
Biology Bonanza
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