The Digestive and Excretory Systems

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The Digestive and Excretory Systems
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The Digestive System

• The functionof the digestive system is to convert
  food into simpler substances (molecules) that can
  be absorbed and used by cells in the body

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The Digestive System

• Path of food through the digestive tract.
• a. mouth
• b. Esophogus
• c. Stomach
• d. Small intestine
• e. Large intestine

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The Digestive System

• a. Mouth mechanical breakdown of food with
  physical and chemical breakdown via saliva. Food
  is broken down into a thick pasty substance
  called bolus.

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The Digestive System

• b. Esophogus The bolus is transported from the
  mouth to the stomach via the esophogus. To do
  this, the esophogus contracts rythmically. These
  contractions are called peristalis.

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The Digestive System

• c. Stomach combination of mechanical digestion
  by grinding and chemical digestion. The stomach
  has a ribbed inner lining to grind the food.
  Chemicals such as hydrochloric acid help break
  down the food.

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The Digestive System

• d. Small intestine the most digestion and
  nutrient absorption occurs here.
• i. pancreas produces digestive enzymes
• ii. Liver produces bile to break down fat
• iii. Gall bladder stores bile

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The Digestive System

• e. Large Intestine removes water from
  undigested material.

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The Excretory System

• The function of the excretory system is to
  maintain homeostasis by maintaining water balance.

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The Excretory System

• Excretory Organs
• Lungs excrete carbon dioxide and water.
• Skin excretes excess salt and water

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The Excretory System

• 2. Kidneys are the main organs of the excretory
  system.
• a. Remove waste products from blood.
• b. Maintain blood pH.
• c. Regulate water content of the blood.

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The Excretory System

• d. Kidneys are on the dorsal side of the body.
• i. it takes approximately 45 minutes for the
  kidney to filter the bodys blood supply.
• ii. The filtered waste travels through the
  ureter.
• iii. The filtered waste is stored in the urinary
  bladder.