Transcript Digestive System

Digestive System
Digestive System Rap
Job of Digestive System
 Break
down food
(macromolecules)
into nutrients &
energy
Review: Macromolecules
 What
macromolecules do
we eat?
Proteins:
Meat, Nuts
Lipids: Oils, Fats
Carbohydrates: Breads,
Sugars
Review: Food Energy
 Which
macromolecule is
our main energy source?

Carbohydrates
Review: Food Energy (cont.)
 Which
macromolecule
stores the most energy?

Lipids
The Food Pyramid
Nutrition
 Nutrients:
Anything
that promotes growth
 Vitamins (Vitamin C)
 Minerals (Iron)
 Macromolecules
Two Types of Digestion
 Mechanical
– physically
breaking food into smaller
pieces (mouth)
 Chemical – food molecules
are broken down by acids
and enzymes (stomach,
small intestines)
Digestive System
Tracking a Piece of Food
1.
2.
3.
4.
5.
6.
7.
Mouth
Esophagus
Stomach
Small Intestine
Large Intestine
Rectum
Anus
Swallowing
 Peristalsis:
wavelike
movement of muscles 
pushes food through
digestive tract
My food went down the
“wrong pipe!”
2
tubes in throat:
trachea & esophagus
 esophagus connects
mouth to stomach
 How does food know
which tube to go
down?
epiglottis
3 Jobs of Stomach
Store food & liquid
2. Mix food & digestive
juices (HCl)
3. Empty into small
intestine
1.
Digestive Juices
 Assist
in breaking down
of food
 Ex. Enzymes
Acid Reflux
Small Intestine
 Absorbs
greatest
amount of
nutrients
 Covered with tiny
finger-like
projections – villi

~20 ft long!
Villi
Increase surface area
for better absorption
(like a towel)
Large Intestine
 Prepares
waste for
removal by absorbing
water
 ~5 ft long!
Digestion: ‘Helper’ Organs
 Salivary
Glands: produce
saliva – starts breaking
down carbohydrates
 Pancreas: produces
enzymes &
regulates
glucose levels
Digestion: ‘Helper’ Organs (cont.)
Liver:
 Produces
bile
 Filters
blood
Digestion: ‘Helper’ Organs (cont.)
 Gall
Bladder:
stores bile
Helps digest
fatty foods