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The Digestive System
Miss Charney
Northville Central School
The Digestive System’s Functions
Digestion: process where body breaks down
food into small nutrient molecules
Absorption: process where nutrient
molecules pass through the wall of your
digestive system into the blood
Waste Elimination: Materials not absorbed,
such as fiber, are eliminated as wastes
Two Types of Digestion
Mechanical: foods are physically
broken down into smaller pieces
Chemical: chemicals produced by the
body break foods into their smaller
chemical building blocks
The Mouth
Mechanical or Chemical?
– BOTH!
Saliva: fluid released when your mouth
waters
– Important in both kinds of digestion
The Esophagus
Where food passes through
from the mouth to the stomach
Mechanical or Chemical?
– NEITHER!
Epiglottis: a flap of tissue that
covers your windpipe as you
swallow
Peristalsis: movement of food
down your esophagus
– Muscles contract to move food
down
The Stomach
J-shaped pouch located in your
abdomen that digests food
Mechanical or Chemical?
– BOTH!
Mechanical in Stomach stomach churning
Chemical in Stomach - stomach
acids (hydrochloric acid) to break
down food (carbs & proteins) and
kill bacteria
The Liver
Located in upper right
portion of the body
(largest organ within the
body)
Bile: a substance that
breaks up fat particulars
Gallbladder: organ right
below the liver that stores
bile (storage)
The Pancreas
Produces enzymes that flow into the
small intestine and help break down
carbs, proteins, & fats
The Small Intestine
Where the thick liquid from
the stomach enters and
almost all absorption of
nutrients takes place (about 6
meters long!)
Mechanical or Chemical?
– CHEMICAL!
Villi: tiny finger-like structures
that absorb nutrient
molecules
– Greatly increase the surface
area of the small intestine
The Large Intestine
Last section of the digestive system
(about 1.5 meters long)
Absorbed Nutrients: as the material
moves through the large intestine, water
is absorbed into the bloodstream; the
remaining material is readied for
elimination from the body
The Anus
Large intestine ends in the rectum
where food is compressed into a solid
form
Anus: muscular opening at the end of
the rectum where waste material is
eliminated