The Human Digestive System

• What is the function of the liver in digestion?

  produces bile, which neutralises hydrochloric acid from the stomach and emulsifies fat to form small droplets with a large surface area
• What is the function of saliva in digestion?

  lubrication to help swallowing – contains amylase to break down starch
• What is the Digestive System Responsible for?

  Changing the food you eat from insoluble molecules into soluble molecules, then absorbing them into the blood.
• What is the function of the digestive system?

  To digest food, absorb nutrients and excrete waste
• What happens at the stomach?

  where digestion occurs
• What does the liver do?

  produces bile
• What do the glands do?

  pancreas & salivary glands - produce digestive juices containing enzymes
• What does the small intestine contain that helps digestion?

  a large number of villi where the absorption of soluble food occurs
• What does the large intestine do?

  absorbs water from the undigested food, producing faeces
• How are the villi adapted to absorb food efficiently? (3)

  They have:

  • a very large surface area - to absorb soluble food molecules by diffusion and active transport
  • a thin wall to provide a short diffusion path
  • a good blood supply to carry the food molecules away to maintain a concentration gradient
• Label the Digestive System:

  A) Mouth

  B) Salivary Glands

  C) oesophagus

  D) Liver

  E) Stomach

  F) Pancreas

  G) Gallbladder

  H) Large Intestine

  I) Small intestine

  J) Anus