Download Digestive System

Digestive System
Parts and Functions
Human Health and Digestion
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Food is our primary source of fuel and
building blocks for body growth, maintenance
and energy requirements
Food can be contaminated with bacteria and
also with chemical pesticides etc. This
contamination can lead to health problems if
ingested.
How much do you know?
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http://www.tvdsb.on.ca/westmin/science/sbi3
a1/digest/digdiag.htm
Types of Digestion
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Physical
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Biting and chewing to initially break down food for
swallowing
Wetting to ease swallowing and movement
Peristalsis (rhythmic contractions) of smooth
muscle around esophagus, stomach, intestines to
move food through the alimentary canal (tube)
Churning of smooth muscle in stomach to mix
food with digestive acid and enzymes
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Chemical
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Breaking down macronutrients into their smaller
sub-units for absorption and transport around the
body
PROTEINS
amino acids
LIPIDS
fatty acids, glycerol
CARBOHYDRATES
simple sugars
Parts and Functions
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Mouth
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Teeth
Tongue
Salivary glands
Epiglottis
Esophagus
Parts and Functions con’t
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Stomach
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Cardiac sphincter
Stomach Lining
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(Acid secretion)
(Enzyme secretion)
(Mucus secretion)
Pyloric sphincter
Parts and Functions con’t
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Small Intestines
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Duodenum
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Ileum
Jejunum
Pancreas
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(Enzyme secretion)
(Enzyme secretion)
Liver
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Gall Bladder
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(Neutralization of acid and emulsification of fats)
Parts and Functions con’t
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Large Intestines
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Rectum
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Ascending
Transverse
Descending
(Storageand compaction)
Anus
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(removal)
Enzyme Action
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Enzymes are specialized proteins
manufactured in the body to help chemical
reactions take place
Some enzymes are especially designed to
BREAK down macronutrients into their
components!
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PROTEINS
LIPIDS
CARBOHYDRATES
amino acids
fatty acids, glycerol
simple sugars
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Enzyme names end in “ase”
There are many digestive enzymes in the
body and each has a SPECIFIC function
Enzymes act as “hands” that hold a molecule
and allow a specific reaction to take place
Having healthy functional proteins means
that this system works efficiently!
MOUTH
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Physical Digestion:
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Biting, chewing
Wetting of food
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SALIVA from salivary gland
Chemical Digestion:
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Starts in the mouth
Especially for those components that are difficult to digest
AMYLASE
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Enzyme found in saliva from salivary gland
Breaks down starch into simple sugars
STOMACH
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Physical Digestion
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Peristalsis (from esophagus)
Churning (to mix)
Chemical Digestion
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enzymes
HCl
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Acid which helps to break down protein
INTESTINES: chemical digestion
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Enzymes:
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breaks down proteins and complex sugars into simple
sugar components
Other Organs: chemical digestion
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From Pancreas:
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Breaks down proteins into polypeptides and
amino acids
Sodium bicarbonate: neutralize stomach acid
From Liver:
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pancreatic juice
bile salts
Manufactured in Liver, stored in Gall Bladder
mixes fats with water to assist in digestion