The Digestive System

Mouth:

As teeth tear, cut, and grind food, three pairs of glands make saliva. These salivary glands are located in front of the ears, under the lower jaw, and under the tongue. Tiny tubes carry the saliva from the salivary glands to the mouth.

Esophagus:

The esophagus of an adult is about 25 centimeters long. Muscles in the esophagus contract and relax to push swallowed food down toward the stomach. The process is something like squeezing toothpaste out of a tube.

Stomach:

Stomach is a bag-like organ with muscular walls. Stomach muscles squeeze and mix food with digestive juice make in the stomachs lining. The juice changes the food, which stays in the stomach for two to four hours. When the food leaves the stomach, it is a thick liquid.

Small and Large Intestines:

The liquid food is pushed into the small intestine, a curled-up tube. If stretched out, an adult’s small intestine would be about 7 meters long. Most digestion takes place in the three to six hours that food stays in the small intestine. Juices made in the lining of the small intestine and other organs mix with food. The juices change the food into nutrients. The nutrients pass through the thing walls of blood vessels in the intestinal lining. Blood carries the nutrients to body cells.The parts of food that cannot be digested move to the large intestine, along with some liquid. The large intestine removes much or the liquid and stores the resulting solid waste until it leaves the body.




References:

http://www.walgreens.com/adamHtml/bodyguides/reftext/images/Peristalsis.jpg. (n.d.). Google. Retrieved October 18, 2012, from http://www.google.com.lb/imgres

http://2.bp.blogspot.com/ Stomach-Digestion.jpg. (n.d.). Google. Retrieved October 18, 2012, from management-of-disease.blogspot.com/2011_02_04_archive.

http://www.umm.edu/graphics/images/en/8710.jpg. (n.d.). Google. Retrieved October 18, 2012, from www.umm.edu/patiented/articles

http://www.infoplease.com/images/ency142mouth001.gif. (n.d.). Google. Retrieved October 18, 2012, from www.infoplease.com/dk/encyclopedia/mouth

Cooney, T. M. (2003). Scott Foresman science: grade 4. Glenview, Ill.: Scott, Foresman.

Questions:

Where are the three glands that make the saliva located at?

How long is the esophagus of an adult person?

How Digestion Starts?

Digestion begins in the mouth

Digestion begins as soon as you bite into food. For example, as you chew a sandwich, your teeth cut and grind the bread and the filling into smaller pieces. Your tongue helps mix the chewed food with saliva, the liquid in your mouth. Saliva makes the food wet and easy to swallow.
Saliva also contains an enzyme, or chemical, that helps break food down so saliva can change the food starches into sugars. That is why you may notice a sweet taste when you chew bread, crackers, and other starchy foods.
When you have finished chewing, your tongue moves the wet lump of food to the back of your mouth. You swallow, and the food enters a tube called the esophagus. Your bite of sandwich is now on its way to the next stop in the digestive system which is your stomach.




References:

Cooney, T. M. (2003). Scott Foresman science: grade 4. Glenview, Ill.: Scott, Foresman.

http://www.howany.com/wp-content/uploads/2010/12/How-Long-Does-it-Take-to-Digest-Food.jpg. (n.d.).Google. Retrieved October 18, 2012, from http://www.howany.com/how-long-does-it-take-to-digest-food


Question:

List the Steps that happen before food enters the stomach?

What the digestive system does?

Food that our body needs 

Of course, the cells that make up your body don’t like or dislike particular foods. However, cells do need food’s nourishing substances that are called nutrients to stay alive and do their work.Some nutrients give you the energy you need to play and do all the other things you do each day. Some nutrients help you grow, because body cells use the nutrients to make new cells. Your body also uses nutrients to make repairs, such as mending broken bone. Certain nutrients help your body work as it should.Any food you at must be changed into nutrients that your cells can use. Your digestive system does this job, which is called digestion.




References:

Cooney, T. M. (2003). Scott Foresman science: grade 4. Glenview, Ill.: Scott, Foresman.

http://www.2food4kids.com/blog/wp-content/uploads/Pyramdlr1.jpg. (n.d.).Google. Retrieved October 18, 2012, from /www.2food4kids.com/blog/nutrients-you-will-need.htm


Questions:

What are the substances in food that the body uses for energy, for growth and repair, or for working well?