The Digestive System

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The Digestive System

• Science
• Chapter 3, pp.120-129

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Websites that Illustrate the Digestive System

• The Digestive System Animation 037
• Animation from mouth to large intestines
• http//www.youtube.com/watch?vq3986Yfl5cU
• Digestion 324
• Animation from mouth to the circulatory system
• http//www.youtube.com/watch?vUTaPUdWAEnE
• Digestion Video 136
• Real Footage from food to small intestines good
  but its cut short
• http//www.youtube.com/watch?vUzl6M1YlU3w

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digestive system

• This system absorbs the nutrients in the food
  that we eat.
• (Nutrients are important because they provide
  energy. We need this energy to grow, develop,
  and do everyday activities.)
• This is done with a special group of organs. The
  organs break down food into small parts. The
  organs then soak up the parts that are useful for
  the body. The parts that are not useful for the
  body are pushed out.

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digestive system

• The digestive system passes on the nutrients to
  the tiny blood vessels in the circulatory system.
• digestive system ? circulatory system

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How does the body break down the food that we eat?
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mouth
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mouth

• Teeth grind food into a bolus
• Salivary glands make saliva to break down bolus
• Tongue moves bolus to ? pharynx
• Swallow moves bolus to ? esophagus
• All this takes 10seconds!

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esophogus
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esophogus

• Has lots of mucus slippery
• Muscles squeeze bolus along to ? stomach

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stomach
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stomach

• Wall adds acids and mucus to break down the bolus
  and make it moist and slippery
• Muscles contract and relax this mixes the bolus
  until its a thick, soupy liquid called chyme
• It takes the stomach 4-6 hrs to do all this
• It can hold more than a liter when it is full!

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small intestine
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small intestine

• Adds more juices to break down the food into an
  even smaller form
• Juices from the pancreas liver are also mixed
  in the small intestine
• The nutrients are absorbed (soaked in) by the
  small intestine
• The needed nutrients pass through the walls
  into tiny blood vessels
• The rest of the soupy liquid moves to the large
  intestine

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liver
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liver

• This organ does many things, but one of its jobs
  is to add bile and other digestive juices to the
  food.
• The bile is added in the first part of the small
  intestine (duodenum)
• Bile is important because it breaks down fatty
  food into small droplets (like rain droplets)

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pancreas

• This organ produces different types of digestive
  juices called the pancreatic juice
• This organ also does many things, but one of its
  jobs is to add pancreatic juice to the food. The
  bolus gets the juice in the first part of the
  small intestine (duodenum)

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gall bladder

• This organ holds the bile
• Bile is a green liquid that breaks down fat into
  tiny pieces like soap does with grease!

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large intestine
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large intestine

• This organ is shorter thicker than the small
  intestine
• It is also sometimes called the colon
• Some water leftover minerals are absorbed
  (soaked in) the colon
• Its job is to take waste (the leftovers of the
  food ) and push it out of the body

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How long does the body take to break down our
food?
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About 24-72 hours!

• Meat vs. vegetable (fiber)
• Water
• Exercise
• Medicine
• Age