Transcript The Digestive System

The Digestive System
Your digestive system
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What is Digestion?
◦ Put it into words…
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The mechanical and chemical breaking
down of food into smaller parts so they
can be absorbed into the body.
Your digestive system
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The digestive system is a series of organs
and glands that break down food into it’s
simplest forms for energy
The GI Tract
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The Gastrointestinal Tract
◦ Is the muscular tube that extends from the
mouth to the esophagus, stomach, small
intestines, large intestines, to the anus
◦
The Mouth
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Mastication (chewing) occurs
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Liquids added to food by the salivary
glands
◦ Enzyme amylase breaks down starch
Epiglottitis closes off
the pathway to the
lungs
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The Esophagus
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Upper Esophageal Sphincter
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Peristalsis takes over
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Lower Esophageal Sphincter (entrance to
the stomach)
Peristalsis
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Due to Smooth muscle
The Stomach
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Strongest muscle of the GI Tract
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Adds liquids, enzymes and grinds food
into a semi-liquid mass called chyme
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Food exits through pyloric sphincter
The Stomach
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Degrades proteins using Hydrochloric
Acid and Pepsin
Has a protective lining
which protects
the body from
gastric juices
The pH Scale
The Liver
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Creates Bile which is key to emulsifying
fat
◦ Bile stored in the gallbladder
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Stores glycogen (storage form of glucose)
◦ Has a role in regulating blood sugar
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Stores most minerals and vitamins
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Receives all nutrients that are taken in
through digestion and packages them for
The Small Intestine
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Made up of the Duodenum, Jejunum and
the Ileum
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Bile reaches the chyme from the gall
bladder and pancreas
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Majority of nutrient absorption occurs
here
The small intestine
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Covered with villi to increase surface area
which allows maximum absorption to
occur
Pancreas
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Part of your Endocrine system
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Secretes enzymes which help further
break down energy nutrients
Releases bicarbonate
which neutralizes the
acidic chyme arriving
from the stomach
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Large Intestine
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Anything that makes it through to the
small intestines
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Water and other fluids are absorbed as
well as some nutrients
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Some fiber is broken down and absorbed
by bacteria living here, the rest leaves the
body
Common Digestive Problems
Choking
 Acid Reflux
 Ulcers
 Diarrhea
 Vomiting
 Irritable
Bowel Syndrome
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Acid reflux a.k.a. Heartburn
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The lower esophgeal sphincter allows
stomach acids into the esophagus
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Causes
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Eating/drinking too much
Tight clothing
Being overweight
Change in body position
Ulcers
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Weakening in the lining of the stomach or
intestines
Leads to internal bleeding, very painful
 Possibly stomach cancer
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Causes
◦ Bacterial infection
◦ Anti-inflammatory drugs
◦ Excessive gastric acid secretion
Other factors affect digestion
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Sleep
◦ Repair and maintenance
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Physical Activity
◦ Improves muscle tone and function
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Mental State
◦ Affects the nerves and hormones during
healthy digestion
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Variety of foods in one’s diet
A Summary of Digestion
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http://www.youtube.com/watch?v=A7jKCfx-0Mo