New News Biology #12

Digestive System

Types of nutrients the human body needs:

Proteins

Carbohydrates

Fats

Problem: These useful nutrients are locked inside fruit & other food

Solution: Breaking-down by physical & chemical components

Actual Digestion Process (in order):

The Mouth: responsible for chewing and creating saliva

Esophagus: The food goes down this “food pipe”

Stomach:

• Contracts walls

• Produces pepsin

• Produces Hydrochloric Acid (used to kill bacteria)

Small Intestine:

• digested food is absorbed into the bloodstream

• can produce enzymes to aid the digestion process

Pancreas: produces lots of digestive enzymes

Gall Bladder:

• stores bile

• neutralizes acid from the stomach

• dissolves fats into smaller droplets.

Small Intestine Adaptations:

• Villi: increase the surface area

• Very good blood supply

• Single layer of surface cells

Large Intestine: removes excess water

THE END

Summary:

Food goes in, down esophagus, into stomach, into small intestine, travels through large intestine, THE END.