DIGESTIVE SYSTEM
WHAT IS THE JOB OF THE
DIGESTIVE SYSTEM?

TO BREAK DOWN FOOD INTO
BIOMOLECULES THAT CELLS CAN
USE.
WHERE DOES DIGESTION
BEGIN?

THE MOUTH- begins mechanical
digestion
HOW IS FOOD MECHANICALLY
BROKEN DOWN IN THE MOUTH?

CHEWING WITH YOUR TEETH
BREAKS FOOD INTO SMALLER
PIECES.
HOW IS FOOD CHEMICALLY
BROKEN DOWN IN YOUR MOUTH?
BY SALIVA THAT CONTAINS ENZYMES
 Enzyme called amylase begins to
break down starches

Food moves from the mouth to
the esophagus….

the tube connecting your mouth to
your stomach.
THE ESOPHAGUS MOVES THE
PARTIALLY DIGESTED FOOD TO THE…

STOMACH- continues mechanical
digestion by churning food.
WHAT IS PERISTALSIS?

SMOOTH MUSCLES THAT CONTRACT
TO MOVE FOOD DOWN THE
ESOPHOGUS
GASTRIC JUICE IS RELEASED INTO THE
STOMACH TO BREAKDOWN FOOD. WHAT IS
GASTRIC JUICE?
A MIXTURE OF MUCUS, WATER,
ENZYMES, & ACIDS
 Hydrochloric acid (stomach acid) has
a pH of about 1-2. Very acidic!

WHERE DOES THE FOOD GO ONCE
IT LEAVES THE STOMACH?

TO THE SMALL INTESTINE
Intestines have many folds
Folds are called villi
 They increase surface area to absorb
nutrients

PANCREATIC ENZYMES WILL
HELP FINISH BREAKING DOWN

CARBOHYDRATES AND PROTEINS
THE LIVER MAKES

BILE- BREAKS DOWN FATS
YOUR DIGESTED FOOD MOVES INTO YOUR BLOOD
STREAM. WHERE DOES THE UNDIGESTED FOOD
AND EXCESS WATER GO?

TO THE LARGE INTESTINE
WHAT HAPPENS TO THE
EXCESS WATER?

IT IS REABSORBED INTO THE BODY
THROUGH THE WALLS OF THE LARGE
INTESTINE
DIARRHEA OCCURS WHEN…
Your large intestine
can’t reabsorb excess
H2O…
 This makes your stool
(feces) watery!

WHAT HAPPENS TO THE
UNDIGESTED FOOD

IT IS EXPELLED FROM THE BODY
FOOD NEVER PASSES THROUGH THE
LIVER OR PANCREAS FOR DIGESTION.

MOUTH  ESOPHAGUS  STOMACH
 SMALL INTESTINE  LARGE
INTESTINE  WASTE LEAVES THE
BODY.