The Digestive System

Total Length from mouth to anus 29 feet 8 inches/9

meters

Total Time food spends in the system Up to 49 hours

Digestion: The process of breaking food down into it’s molecular components so that the nutrients may be absorbed into the blood and then into cells of the body.2 Types:

Mechanical: Takes place in the mouth, teeth physically break food into smaller pieces.

Chemical: Happens in mouth and stomach when enzymes and acids to break down food into a “chemical soup”.

Esophagus The muscular tube

connecting the throat to the stomach.

A small “flap” near the top, the epiglottis, closes over the trachea (windpipe) when you swallow so that food cannot get into the lungs.

The esophagus pushes food toward the stomach by making muscular “wave” motions called “peristalsis”.

This is why you can swallow your food while upside-down or in space.

http://www.youtube.com/watch?v=o18UycWRsaA http://player.discoveryeducation.com/

index.cfm?guidAssetId=F11F4DC2-6C5E-4826-8AC2-0C51AD634FC7&blnFromSearch=1&productcode=DETB

The stomach is a muscular hollow organ that dissolves food using strong acids- chemical digestion.

The stomach also churns and grinds food- mechanical digestion.

The lining of the stomach is covered in mucus. This prevents the stomach acids from digesting itself.

When a problem occurs and the lining of the stomach starts to get eaten away, we call it an “ulcer”.

http://www.youtube.com/watch?v=SWMWsOXlBwE

Small Intestines The small intestines

can be up to 26 feet long, are called “small” because they are not very wide in diameter.

They absorb nutrients into your blood.

The Large Intestine called the large intestine because it is 2-3

inches wide but only about 5 feet long. squeezes the last water and nutrients out of

the leftovers. the “holding tank” for anything that cannot

be digested and absorbed.

Exiting the body!

“Poop” aka “feces”, is the squeezed remains of the food you didn’t digest. Feces smells because of bacteria that live in the Large Intestine and help us digest our food.

The bacteria give off a nice mixture of foul smelling gasses also known as flatulence (farts)

Diarrhea happens when the intestines are irritated and release the feces before the last water has been absorbed.

Poop with higher gas content will stay on the surface of the water, thus the name “floater”.

Liver

2 main roles:1. Adds “bile,” a digestive chemical to the

small intestine which helps digest fats. (bile is stored in an organ connected behind the liver called the gallbladder)

2. All the blood in the body passes through the liver every 3 minutes and is filtered of impurities and toxins.

Pancreas Secretes digestive enzymes into the small

intestine that help break down protein, starches, and fats that we eat.

The pancreas helps to regulate insulin levels that control the amount of sugar in the blood.