Download The Digestive System

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