The Digestive

System

Digestion involves:

• Breaking down of food into smaller

pieces(mechanical or chemical)

• The mixing of food

• Movement through the digestive

tract

How Food is digested

Digestive System

Description

• The digestive tract is a series of hollow

organs joined in a tube from the mouth to

the anus. Food passes through the

digestive tract.

• Accessory organs include the liver, gall

bladder, and pancreas. Food does not pass

through these organs.

Identify the organs of

the digestive system

Mouth

• Teeth bite off and chew food into a

soft pulp that is easy to swallow.

• Chewing mixes the food with saliva,

from salivary glands around the

mouth and face, to make it moist

and easy to swallow.

Mouth

• Enzymes in the saliva begin digestion of carbohydrates.

• Mechanical digestion - teeth

• Chemical digestion – saliva

• 11 cm long

Esophagus

• The esophagus is a muscular tube. It takes food from the throat and pushes it down through the neck, and into the stomach.

• It moves food by waves of muscle contraction called peristalsis.

• About 25 cm long

Stomach

• The stomach has thick muscles in its wall that contract to mash the food into chyme.

• Strong digestive juices in the lining of the stomach cause a chemical breakdown of food and dissolve nutrients.

• About 22 cm long

Small Intestine

• This part of the digestive tract is narrow, but very long - about 20 feet or 690 cm.

• Food is broken down into small enough pieces so nutrients can be absorbed into the blood(diffusion) and taken to vital organs.

• Enzymes continue the chemical reactions on the food.

Large Intestine

• Absorbs extra nutrients

and water

• Forms wastes into solid

feces

• About 125cm long

Gastrodigestivestsytem.com

Rectum and Anus

• The end of the large

intestine and the next

part of the tract; the

rectum stores the feces.

• Feces are finally

squeezed through a ring

of muscle, the anus,

and out of the body.

Gastrodigestivestsytem.com

Pancreas

• Makes digestive juices

called enzymes which

help to digest food

further as it enters the

small intestines.

Aboutkidshealth.ca

Gall Bladder

• A small baglike part

under the liver.

• Stores a fluid called

bile, which is made in

the liver.

• It helps to digest fatty

foods and also contains

wastes for removal. Aboutkidshealth.ca

Liver

• The liver is like a food-processing factory

• Blood from the intestines enters to the liver bringing nutrients

• It stores some of what it receives.

• Changes it into another form or releases the nutrients back into the blood

Aboutkidshealth.ca

For more information

about the digestive

system, click here

http://kidshealth.org/kid/body/digest_noSW.html