THEDIGESTIVE

SYSTEM

• Digestion is the process that breaks down food into smaller molecules so they can be absorbed and moved into the blood for use in the body’s cells.

• Digestion is both mechanical and chemical

• Mechanical digestion takes place when food is chewed, mixed, and churned – the physical breakdown of food.

• Chemical digestion occurs when chemical reactions break down food molecules

• Chemical digestion is possible because of enzymes

• An enzyme is a type of protein that speeds up the rate of chemical reaction in your body

• Peristalsis refers to the wave of muscle contractions that move food through the digestive tract

ORGANS OFTHE DIGESTIVE SYSTEM

• Digestion starts in the mouth, which includes the tongue, teeth and salivary glands

• The esophagus is a muscular tube that connects the throat to the stomach. –A structure called the epiglottis covers the

opening to the windpipe to prevent choking

• The stomach is a muscular “bag” where a major part of digestion occurs.

• Food moves through the stomach in 2 to 4 hours and is changed into a liquid consisting of gastric juices and partly digested food.

* This liquid is called chyme.

• The small intestine runs between the stomach and the large intestine.

• As chyme leaves the stomach, it enters the duodenum, the first part of the small intestine

• The pancreas is a large gland behind the stomach that secretes enzymes into the duodenum.

• The pancreas also produces insulin, a hormone that regulates the amount of sugar in the blood

• The large intestine absorbs water from the undigested mass of chyme. After excess water is absorbed, the remaining materials become more solid. The large intestine is also called the colon.

• The last parts of the large intestine are the rectum and the anus. These organs control the release of solid waste from the body.