Animation on
digestion for
children
John Levasseur
Springfield Central High School
Based on PowerPoint Presentation found at:
http://sun.menloschool.org/~cfat/powerpoint/biology/index.html
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What are the parts of a human heart? Check your knowledge of the heart
at this site: http://www.kscience.co.uk/animations/heart_labelling.htm
What are the parts of human lungs? Check your knowledge of the Lungs at
this site: http://www.kscience.co.uk/animations/lungs.swf
What is the purpose of the circulatory system? What is the purpose of the
circulatory system?
What is the purpose of the respiratory system?
What are the more scientific names for red and white blood cells?
What blood vessel takes blood away from the heart?
What blood vessel returns blood to the heart?
What part of the heart receives blood and what part actually pumps blood?
What part of blood is responsible for clotting?
What is the function of capillaries?
What is the function of alveoli?
What is the function of the epiglottis?
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4.1 Digestive System
Explain generally how the
digestive system converts
macromolecules from food
into smaller molecules that
can be used by cells for
energy and for repair and
growth.
Know the digestive
system’s key structures’
form and functions: mouth,
pharynx, esophagus,
stomach, small and large
intestines, rectum.
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The digestive system purpose is
to breakdown the food that we
eat into the molecules that can be
absorbed by our bodies for
nutrition.
The digestive system consists of
two sets of organs and body
structures: The digestive tract
(alimentary canal) and the
accessory digestive structures.
◦ The digestive tract is the passage
way made of the digestive system’s
organs that passes through the
body starting at the mouth and
ending with the anus.
◦ Accessory digestive system
structures would include: the teeth,
tongue, epiglottis and the glands
that produce the enzymes need for
digestion.
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Introduce yourself to the
structures of the digestive
system:
http://www.innerbody.com/anim/mouth.html
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View this video at: http://health.howstuffworks.com/adam-200142.htm
View this interactive animation of digestion:
http://kitses.com/animation/swfs/digestion.swf
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Food is broken down for absorption by the body two ways: mechanically and
chemically.
◦ Mechanical breakdown of food includes chewing in the mouth and segmentation
during peristalsis.
◦ Chemical break down is done by enzymes and acids produced in glands along the
digestive tract.
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The digestive glands that act first are in the mouth—the salivary glands.
The next set of digestive glands is in the stomach lining. These glands
produce stomach acid (HCl) and an enzyme that digests protein.
After the stomach empties the food and juice mixture into the small
intestine, the juices of two other digestive organs mix with the food.
◦ One of these organs, the pancreas, produces a juice that contains a wide array of
enzymes to break down the carbohydrate, fat, and protein in food. Other enzymes
that are active in the process come from glands in the wall of the intestine.
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The liver, produces yet another digestive juice—bile. Bile is stored between
meals in the gallbladder. At mealtime, it is squeezed out of the gallbladder,
through the bile ducts, and into the intestine to mix with the fat in food.
◦ The bile acids dissolve fat into the watery contents of the intestine, much like
detergents that dissolve grease from a frying pan. After fat is dissolved, it is
digested by enzymes from the pancreas and the lining of the intestine.
Text From:
http://digestive.niddk.nih.gov/ddiseases/pubs/yrdd/
Animation on Food to Fuel
The breakdown of food into digestible
molecules begins in the mouth. Food is
ground by chewing and moistened by
saliva. Saliva also begins the chemical
breakdown of food with an enzyme for
hydrolysis of complex sugars amylase.
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Chewing
◦ Mechanical breakdown by
grinding and tearing of food.
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Saliva
◦ A liquid secretion into the mouth
that contains enzymes which start
the chemical breakdown of food.
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Bolus
◦ After chewing, food is shaped into
a ball (bolus) and forced into the
pharynx by the tongue.
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Epiglottis
◦ When we swallow a flap of
skin called the epiglottis
covers the trachea
preventing food from going
into the lungs.
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Esophagus
◦ The canal from the pharynx
to the stomach is called the
esophagus.
◦ Food moves down the
esophagus by peristalsis,
the involuntary contraction
of the smooth muscle
Watch this animation on
swallowing:
http://health.howstuffworks.com/
adam-200089.htm
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Peristalsis is the rhythmic contraction
of smooth muscles to propel
contents through the digestive tract.
After food is chewed into a bolus and
swallowed into the esophagus
smooth muscles will contract behind
the bolus to prevent it from being
squeezed back onto the mouth.
Rhythmic waves of contractions work
to rapidly force the food into the
stomach.
◦ This process works in one direction only and
its sole purpose is to move food from the
mouth into the stomach.
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A peristaltic wave pushes the bolus
through the esophagus into the
stomach. The wave travels down to
the stomach even if the bolus of food
descends at a greater rate than the
wave itself, and will continue even if
for some reason the bolus gets stuck
further up the esophagus.
Text from:
http://en.wikipedia.org/wiki/Peristalsis
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The stomach is found under the
diaphragm in the upper part of
the abdominal cavity.
◦ Food enters the stomach after
having been chewed, swallowed,
and passed through the
esophagus.
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The stomach’s size can change
dramatically with the amount of
food being stored.
The cardiac sphincter is a ring
of muscle that prevents food
from reentering the esophagus
while the stomach is
contracting to form a semisolid
mixture known as chyme.
The pyloric sphincter separates
the small intestine from the
stomach.
http://www.acm.uiuc.edu/sigbio/project/digestive/middle/stomach.html
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http://www.acm.uiuc.edu/sigbio/project/digestive/middle/stomach.html
The stomach functions as a
pouch to receive the chyme where
more mechanical and chemical
breakdown can take place.
In the stomach hydrochloric acid
and protein digesting enzymes
mix with the food to continue the
process of preparing the food for
absorption into the blood stream.
There are three layers of smooth
muscle that run lengthwise,
around making the stomach one
of the strongest internal organs.
The folds in the lining of the
stomach are known as rugae
secrete gastric juice and
hydrochloric acid.
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The small intestine is the largest part of
the digestive system and is the key
organ of this system.
The small intestine is composed of three
sections:
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duodenum (1foot long)
jejunum (5-8 feet long)
ileum (16-20 feet long).
In the small intestine nutrients from
food are absorbed into the blood stream
via osmosis.
◦ To pass through the small intestine’s wall,
food particles must be broken down to the
level of molecules.
 Complex sugars to Monosaccharides
 Proteins into simple peptides or amino acids
 Fats into simple lipid compounds
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The duodenum is the portion of the
small intestine where different
enzymes are added to the digesting
food, (chyme).
Remember enzymes control chemical
reactions in living things.
◦ The names of enzymes end with the
letters "ase". The small intestine secretes
sucrase (breaks sucrose into glucose and
fructose); maltase (breaks maltose into
glucose); and lactase (breaks lactose into
glucose and galactose, lactase is missing
in a good percentage of people). Another
enzyme secreted into the duodenum is
petidase used to split peptides (from
proteins) into amino acids, and lipase to
break down fat into glycerol and fatty
acids.
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Text from:
http://www.becomehealthynow.com/mira2_front/printpage.php?id=730
The duodenum receives bile from the
liver and gallbladder.
◦ Bile decreases the surface tension
between large fat globules and water,
and break lipids into smaller globules
that can be acted upon by lipase,
amylase, trypsin, chymotrypsin and
sodium bicarbonate are received from the
pancreas upon hormonal signals from
pancreozymin and other hormones
(produced in the small intestine) and
neural signals from the vagus nerve.
•Small Intestine Images
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The Large Intestine is also
known as the colon.
◦ There are four sections to the
large intestines:
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Ascending colon
Tarnsverse colon
Descending colon
Rectum
The large intestine begins at the
end of the small intestines and
ends at the rectum
The large intestine absorbs
water from the chyme and feces
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See Animation
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What is the purpose of the digestive system?
How is mechanical breakdown of food accomplished?
How is chemical breakdown of food accomplished?
What is peristalsis?
Where in the digestive tract are nutrients absorbed into the blood stream?
Where in the digestive tract is water reabsorbed into the body?
What is the function of the liver?
What is the function of the stomach?
What is the function of the small intestine?
What is the function of the colon?
What is the function of the gall bladder?
What is the function of bile?
What is the function of enzymes?
What is a bolus?
What is the acid found in stomach?