Digestive
systems
Life Process?
Nutrition
Transport
Autotrophic vs. heterotrophic
Eat other things for fuel
When is food “in you”?
Raw materials for synthesis
and assimilation
Human Digestive System
Bringing food close and broken
down enough to be absorbed.
Two categories of organs
• Alimentary canal AKA digestive tract AKA GI tract
– “Food tube”; food passes through these
organs
• Accessory organs
– Add digestive juices to food.
Alimentary
Mouth: Put food in here
Pharynx: Throat
Esophagus (5): Peristalsis
(squeezing food through the
tube) begins. Brings food to
stomach.
Accessory
Teeth (1) : Chew food ->
increases surface area of
food for enzyme action
Tongue (2) : Tastes. Is this
food?
Salivary glands (3) :
Produce saliva: enzymes and
lube
Epiglottis (4) : Closes trachea
(windpipe) during swallowing
Alimentary
Stomach (7/14): Food is
ground into a paste. Protein
digestion begins
Accessory
Liver (6/17) : Produces bile:
breaks fat into smaller
blobs (emulsifies)
Gall bladder (16) : Stores
up bile for fatty meals
Pancreas (8/15) : Produces
other digestive enzymes
Alimentary
Small intestine (10):
Digestion completes and most
absorption of nutrients. Has
adaptation for increased
surface area (more absorption)
Large intestine (9):Water
absorption
Rectum (12): Storage of feces
Anus (13): Muscle that holds it
in/lets it out
Accessory
Appendix (11) : Helps
control gut bacteria
populations?