Download The Digestive System

The Digestive System
6th, 7th, & 8th Grade Health
Digestive System
Warm-up
• What is the function of the
Respiratory System?
• Name the parts of the
Respiratory System?
Learning Objectives
• To recognise the organs involved in digestion;
• To understand the major functions of each body
part in the digestive process;
• To understand the four major phases of
digestion;
• To understand the functions of different
enzymes.
Major Functions of the Digestive System
• Break down ingested food
• Put nutrients into the bloodstream
• Remove waste from the body
Organs of the Digestive System
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Mouth- teeth, salivary glands, tongue
Esophagus
Stomach
Small Intestine
Large Intestine
Pancreas
Liver
• Gall bladder
Accessory
Organs
Mouth
• Digestion begins here!
• Teeth and tongue are used in mechanical
digestion- physical breakdown of food
• Saliva and enzymes begin chemical digestionchemical breakdown of food
Esophagus
• Muscular tube that connects mouth to stomach
• Moves food downward by peristalsis, or
muscular contractions
• Epiglottis seals off windpipe during swallowing to
prevent choking
Stomach- Mechanical and
Chemical Digestion
• Muscular pouch that
expands to hold your
food
• Hydrochloric acid (HCl)
and the enzyme pepsin
combine to form gastric
juice
Stomach- Mechanical and
Chemical Digestion
• A gummy coating of
mucus protects the
stomach lining from
the strong chemicals
• Chyme, a thick liquid
containing partially
digested food, is
produced here
Small
Intestine
• Most chemical digestion occurs here!
• Inner surface is covered in villi and microvilli,
millions of tiny finger-like projections that absorb
nutrient molecules from the chyme
• The villi create a large surface area, so as
many nutrients as possible can be absorbed
Other Facts of the Small Intestine
• Longest portion of the digestive tract
• Tube that is 20- 25 feet long
• Food stays in your small intestine for 4 to 8
hours
Liver
• Makes bile to break up fat
• Stores nutrients, like vitamins and sugars until
your body needs them
• Breaks down toxins
Gallbladder
• Temporarily stores bile and releases it into the
small intestines
• Storage tank for bile (a greenish-yellow liquid)
• Helps your body break down and use fats
• Located under your liver
• Shaped like a pear
Pancreas
• Makes digestive enzymes
• Makes hormones that regulate sugar levels
• Helps you digest food by breaking down sugars
Large Intestine
• No digestion occurs here
• Water is absorbed from remaining food
• Bacteria feed on material passing through and
produce Vitamins (K) vital to our health
• Waste material, feces, is prepared for elimination
from the body
Other Facts of the Large Intestine
• Tube that is 5 feet long
• Gets waste from small intestine
• Waste stays for 10 to 12 hours
Rectum
• Stores feces until they can be expelled through
the anus.
Large Intestine
Videos
• http://www.neok12.com/video/DigestiveSystem/zX4559475700465170435873.htm
• http://kidshealth.org/kid/htbw/DSmovie.html
Some more videos
• http://www.youtube.com/watch?v=P5lyQUtq1KQ
• http://kidshealth.org/kid/htbw/_bfs_DSmoviesource.
html
• http://www.youtube.com/watch?v=q3986Yfl5cU
• http://kitses.com/animation/swfs/digestion.swf
The End!