Download digestive system lesson 6

BODY SYSTEMS
DIGESTIVE SYSTEM
OBJECTIVES
• identify the parts and functions of the
digestive system.
• explain the process of excretion.
• describe ways to prevent problems to the
digestive and excretory systems
DIGESTIVE SYSTEM
The digestive system
begins in the mouth and
finishes with the
elimination of used-up
fuel in the form of wastes.
digestive system The
body system that converts
fuel into usable energy
DIGESTION
Digestion involves both mechanical and
chemical processes.
digestion The process of changing food
into material the body can use
DIGESTION
Mechanical processes include chewing and
mashing food into smaller pieces.
DIGESTION
The chemical process
involves breaking food
down into particles with
digestive enzymes.
enzymes Proteins that
affect the many body
processes
DIGESTION
Digestive enzymes speed up the breakdown
of food.
MOUTH AND TEETH
Saliva contains enzymes that begin breaking
down the food in your mouth.
MOUTH AND TEETH
When taste buds on your tongue sense
flavor, your mouth produces saliva.
saliva A fluid made by the salivary glands
THE STOMACH AND SMALL
INTESTINES
The esophagus is a
muscular tube the pushes
food down into the
stomach in a process
called peristalsis.
Peristalsis is a series of
involuntary waves that
carry food particles along.
THE STOMACH AND SMALL
INTESTINE
Glands in the stomach wall release gastric
juices, a blend of hydrochloric acid and
enzymes.
A protective stomach lining prevents
hydrochloric acid from digesting the
stomach itself.
THE STOMACH AND SMALL
INTESTINE
Most of digestion takes place in the small
intestine.
small intestine A coiled, tube-like organ
that is about 20 feet long
THE STOMACH AND SMALL
INTESTINE
In the small intestine, nutrients are
separated from the bulk of the food before
entering the bloodstream.
ORGANS THAT AID DIGESTION
LIVER The liver produces bile, a substance that helps
break down fats.
GALLBLADDER The gallbladder stores bile and
release it into the small intestine as needed.
PANCREAS The pancreas makes digestive
enzymes which are released directly into the small
intestine
EXCRETORY SYSTEM
The excretory system is responsible for
excretion.
excretory system Your body’s waste
removal system
excretion The process of removing wastes
from the body
PROCESS OF EXCRETION
Food particles that cannot be digested move
from the small intestine to the colon.
colon The large intestine
PROCESS OF EXCRETION
The lining of the colon absorbs much of the
liquid contained in the food particles.
PROCESS OF EXCREATION
Some of the liquid waste materials are
filtered out by the kidneys and leave the
body as urine.
kidneys Organs that filter water and
dissolved wastes from the blood an help
maintain proper water and salts in the
body
PROCESS OF EXCRETION
Solid wastes products that remain are called
feces and leave the body through the
anus.
PROBLEMS
Indigestion
Diarrhea
Heartburn
Ulcers
Gallstones and kidney stones
Appendicitis
Hemorrhoids
CARE
Eat a variety of nutritious foods
Do not rush your meals
Chew your food thoroughly
Drink plenty of water
Wash your hands regularly