Transcript The Digestive System

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Amanda Dermer
Keane Archibald
Dayana Jimenez
Courtney Blazer
 Chapter
18: Lesson 1
 Eight
Graders
 Age: 13-14
 Digestion
 Absorption
 Elimination
Digestive System
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The purpose
define the function of
each organ
 the pathway food
takes through the
digestive tract
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Digestive System
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The organs and parts of
the digestive pathway:
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Oral cavity
Pharynx
Esophagus
Stomach
Small Intestine
Large Intestine
Digestive System
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Teeth
Tongue
Liver
Pancreas
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The process that breaks down food into
substances that can be absorbed by the body for
energy, growth, and repair.
Ingestion:
Mouth, Teeth & Tongue
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The function of the mouth is to
ingest food sources
The teeth are used for
mastication
 breaking food down into
smaller pieces to be
The tongue forms food into a
ball to prepare for swallowing
Ingestion:
Mouth, Teeth & Tongue
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The mouth, teeth, and tongue play a role in
mechanical digestion.
Mechanical digestion physically prepares food
for chemical digestion by enzymes.
Salivary Glands
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Secretes saliva
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a watery solution
containing an enzyme that
starts the digestion
Cleanses the mouth
Dissolves food chemicals
Moisten food
Salivary Glands
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The salivary glands begin the process of
chemical digestion.
Pharynx
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After leaving the mouth, food is
passed on to the pharynx.
As you swallow:
 Uvula: prevents food from
passing into the nasal cavity.
 Epiglottis: prevent food
from entering the respiratory
tract.
Esophagus
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Primary Function;
 Carry foods and
liquids to stomach
 Peristalsis moves food
though the digestive
tract
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Food passes through the
pharynx into the
esophagus
 Extends from the
pharynx to the
stomach
Stomach
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Located below the
esophagus
A hollow, saclike organ
 Consists of three layers
of muscles
 Flexible, allowing it to
expand when you eat.
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Stomach
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A temporary “storage tank” where the chemical
breakdown of proteins begin.
The food is mixed together with gastric juices,
secretions from the stomach’s lining
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containing pepsin and hydrochloric acid.
Stomach
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As the stomach fills:
stomach contract
 churn the food and
gastric juices together
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This produces chyme
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a creamy, fluid mixture of
food and gastric juices .
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The passage of digested food from the digestive
tract into the circulatory system.
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The small intestine is the major absorption site.
Small Intestine
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The major part of digestion and
absorption
20 to 23 feet in length
Secretions from the pancreas,
liver, and intestinal juices
complete the chemical
breakdown of all food.
Small Intestine
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Millions of fingerlike
projections called villi
Each villus contains a
network of capillaries
which absorb digested
food particles from the
small intestine.
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Once food particles
enter the capillaries in
the villi, they are carried
throughout the body by
the blood.
Peristalsis moves the
chyme from the stomach
into
Small Intestine
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Three parts to the small
intestine
 Duodenum
 Food enters here
from the stomach
 Jejunum
 The middle section
of the SI
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Ileum
 Allow one way
flow into the large
intestine.
The Liver & Pancreas
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Liver: 2nd largest organ in the
body.
 Acts to clear the blood of
toxins then excreting them
in the bile.
 Bile is a yellowish-green,
bitter fluid important in
the breakdown of fats.
Liver & Pancreas
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The pancreas produces 3 enzymes:
Trypsin, which digests proteins
 Amylase, which digests carbohydrates
 Lipase, which digests fats
 Located in the C of the SI’s duodenum.
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Gallbladder
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Storage organ for bile
produced from liver
Located below the liver
The small intestine
stimulates the release of
bile into the duodenum.
Not required for
digestion
Large Intestine
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Starts Ascending colon
Ends at the anus.
 A.K.A. the colon
 5 to 6 feet long
Large Intestine
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Unabsorbed materials:
 leave the small intestine in the form of liquid and
fiber
 enter the large intestine
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Absorbs most remaining
 Water
 Vitamins
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The expulsion of undigested food or body
wastes.
Elimination
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Harmless bacteria in the
large intestine change the
consistency of the
undigested food into a
semisolid waste, called feces
Feces passes from the body
through the anus
Termed “bowel movement”
Activity: Reconstructive Surgery
Lifestyle & Dietary Factors
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Eat at least 3 servings from a variety of fruits
and vegetables to avoid constipation
Practice good hand washing hygiene
Throw food away after it falls on the floor
Wash all foods before eating
Decrease caffeine consumption
Medications
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Some over the counter drugs that will help aid in
the relief of constipation and diarrhea.
Diarrhea
a. Imodium AD
b. Pepto-Bismol
 Constipation
a. Citrucel
b. Ex-Lax
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Stats of Constipation & Diarrhea
Deaths due to Constipation & Diarrhea
Constipation
17%
Infectious Diarrhea
Constipation
Infectious
Diarrhea
83%
Create your own digestive tract
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Each group will be representing a different part
the digestive tract
The group will stand in front of the class and
present the pathway of food from ingestion to
excretion
 Each person will state the organ they are and
their function
 Be creative and have fun with the activity