Transcript Step 1

04/18/2013
Have your Human
Body Book out and
be ready when the
bell rings.
Days to
the Biology
STAAR…
DIGESTIVE SYSTEM
Digestive
system…
Functions
• break down food into
smaller parts
• absorbs digested food
• distributes nutrients to
cells
• eliminates undigested
materials
Pathway of Food
Mouth
Esophagus
Pancreas
Liver
Gallbladder
Stomach
Small
Intestine
Large
Intestine
Rectum
How does digestion start?
Step 1 - Mouth
Chewing breaks down
food into smaller
pieces.
Enzymes in saliva help!
Step 2  Esophagus
Peristalsis squeezes
food from the throat
to the stomach.
Smooth muscles at
work.
Step 3  Stomach
Stores food and
breaks it into tiny
pieces.
Mixes food with
digestive juices.
Step 4  Liver
Produces bile that
helps break down
fats.
Step 5 
Gallbladder
Stores bile made
by the liver.
Step 6  Pancreas
• Produces enzymes
to digest fats and
proteins.
• Produces insulin
• Neutralizes acids
that enter the small
intestines.
Step 7  Small
Intestine
• Nutrients from food
pass into the
bloodstream.
• Villi increase surface
area to aid
absorption.
Step 8  Large
Intestine
Absorb water from
remaining food.
Pass useless waste
material from the
body
Steps 9 & 10  Rectum and
Anus
9. Rectum
– Stores waste
before defecation
10. Anus
– Muscular ring
that controls
defecation
Salivary
Gland
Mouth
Tongue
Epiglottis
Esophagus
Liver
Gallbladder
Stomach
Pancreas
Large
Intestine
Small
Intestine
Rectum
EXCRETORY
SYSTEM
Functions of Excretory System
1. Waste removal
2. Maintain homeostasis of
body fluids
Inside
your
piggy!!
Organs of Urinary System
Kidneys
Ureters
Urinary
Bladder
Urethra
Step 1  Kidneys
• Filter blood to remove waste
and maintain homeostasis of
body fluids
Step 2  Ureters
• Tubes
connecting
kidneys and
urinary
bladder
Step 3  Urinary
Bladder
• Smooth
muscle bag
that stores
urine
Step 4  Urethra
• Tube that
carries
urine out
of the
body