digestive system chapter 16 section 3 · tuesday, may 17, 2011. small intestine the small intestine...
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Digestive SystemChapter 16 Section 3Final Digestion and Absorption
Tuesday, May 17, 2011
Small IntestineThe small intestine is the part of the digestive system where most of the chemical digestion and absorption takes place.
It is called the small intestine because of the diameter, not the length. It is about 6 meters long.
By the time food reaches the small intestine it has become a thick liquid that needs to be digested.
Starches proteins and fats are digested in the small intestine.
Enzymes form the live, gall bladder and pancreas enter the small intestine and aide in chemical digestion.
Tuesday, May 17, 2011
Small intestine AbsorptionThe small intestine has small structures called villi which make it well suited for absorption.
Villi help to increase surface area. The extra surface area allows for greater absorption. Blood vessels in the villi allow nutrients to enter into the bloodstream for transport.
Tuesday, May 17, 2011
Liver and Gall BladderThe liver is located in the upper abdomen an is the largest and heaviest organ in the body.
Besides breaking down medicines and eliminating nitrogen, the liver produces bile which breaks down fats(lipids).
Bile flows from the liver and is stored in the gall bladder.
Bile is an enzyme and does not chemically digest food. It breaks fats into smaller molecules which are chemically broken down in the pancreas.
Food never enters into the liver or gall bladder.
Tuesday, May 17, 2011
Pancreas
The pancreas is a triangular organ that lies between the stomach and the first part of the small intestine.
The pancreas produces enzymes which flow into the small intestine and help break down starches, proteins and fats.
Food never enters the pancreas.
Tuesday, May 17, 2011
Large Intestine (Colon)The large intestine is the last section of the digestive system. It is about 1 and a half meters long.
It contains bacteria which feed on the material passing through which helps to produce vitamins.
As material moves through the large intestine water is absorbed into the bloodstream.
The remaining material is moved to the rectum where waste is compressed into solid form. It is then expelled from the body through the anus.
Tuesday, May 17, 2011