Post on 03-Jan-2016
Digestive systems
Life Process?
NutritionTransport
When is food “in you”?
Autotrophic vs. heterotrophic
Eat other things for fuel
Raw materials for synthesis and assimilation
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.
AlimentaryMouth: Put food in here
Pharynx: Throat
Esophagus (5): Peristalsis (squeezing food through the tube) begins. Brings food to stomach.
AccessoryTeeth (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
AlimentaryStomach (7/14): Food is
ground into a paste. Protein digestion begins
AccessoryLiver (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
AlimentarySmall 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
AccessoryAppendix (11) : Helps
control gut bacteria populations?