Science Starter
 What does your digestive system
do for you?
 My digestive system is a group of
organs that work together to digest
food so that the nutrients from food
can be used by the body.
Digestive System
 My cells tell my brain that they
need energy.
 Digestive System: the organs
that break down food so that it
can be used by the body.
Digestive System at a Glance
 The digestive tract begins
in my mouth, ends at the
anus, and is nine meters
long.
Breaking Down Food
 The two types of digestion are
mechanical and chemical.
 Mechanical mashes food, chemical
breaks it down into single
nutrients.
 Carbohydrates, proteins, and fats
make up the three types of
Nutrients.
Chemical vs. Mechanical Digestion
Chemical
Digestion
Saliva In my mouth
Break down food
Enzymes and acids in
my stomach
Mechanical
Digestion
Muscles In my
stomach
teeth In my Mouth
Reflection Question
 What did you learn today about why
you need to improve on your
technology skills?
Science Starter
 What are the jobs for mechanical and
chemical digestion?
 The breaking and mashing of food is
called mechanical digestion. Chemical
digestion is the process that breaks
large food molecules into simpler
molecules.
Digestion Begins in the Mouth
 Teeth grind up food in my mouth.
 Saliva makes my food slippery so it will
go down my esophagus easily.
 My tongue pushes food into my
esophagus which forces it into my
stomach.
Esophagus
 A long, straight tube
that connects the
pharynx to the stomach.
Stomach
 The saclike, digestive organ between the
esophagus and the small intestine that
breaks down food into a liquid by the
action of muscles, enzymes, and acids.
Harsh Environment of the Stomach
 My stomach turns food into a soupy
liquid called chyme, and then it passes
into my small intestine.
Pancreas and Small Intestine
 My pancreas sends fluid to the chyme to
make it less acidic.
 My small intestine is where the nutrients
are pulled from food and put into my
blood (plasma).
Pancreas
 The organ that lies behind the stomach
and that makes digestive enzymes and
hormones that regulate sugar levels.
Small Intestine
 The organ between the stomach and the large
intestine where most of the breakdown of food
happens and most of the nutrients from food are
absorbed.
Liver
 The largest organ in the body; it makes
bile, stores and filters blood, and stores
excess sugars as glycogen.
Gallbladder
 A sac-shaped organ that stores bile
produced by the liver.
Large Intestine
 The wider and shorter portion of the
intestine that removes water from
mostly digested food and that turns the
waste into semisolid feces, or stool.
Science Starter
 What is the purpose of
your digestive system?
Science Starter
 Rate yourself on a scale of 1-5. How much effort do
you put into your schoolwork? Explain why you feel
this way.