bio chapter 21

  1. Herbivores
    Plant-eaters (cattle, snails, sea urchins)
  2. Carnivores
    Meat-eaters (lions, hawks, spiders)
  3. Omnivores
    Eating both plants and other animals (humans, roaches, crows, raccoons)
  4. Animals obtain and digest their food 4 ways:
    • Suspension feeding
    • Substrate feeding
    • Fluid feeding
    • Bulk feeding
  5. Food is processed in 4 stages:
    • Ingestion
    • Digestion
    • Absorption
    • Elimination
  6. Mechanical digestion
    • Breaks food down into smaller pieces
    • Smaller pieces are easier to swallow
    • Smaller pieces have more surface area exposed to digestive fluids
  7. Chemical digestion
    Breaks down large organic molecules into their components
  8. Most animals have an alimentary canal:
    • Mouth
    • Anus
    • Specialized regions
  9. Sphincters
    Control the movement of into and out of digestive chambers
  10. The pyloric sphincter
    • Regulates the passage of food from the stomach to the small intestine
    • Limits the upward movement of acids into the esophagus
  11. The trachea
    Conducts air to the lungs
  12. Esophagus
    Conducts food from the pharynx to the stomach
  13. Swallowing reflex
    • Food moves from the pharynx into the esophagus
    • Prevents food from entering the trachea
    • A coughing reflex helps expel materials that accidentally enter the trachea
  14. Stomach
    Stores food and breaks it down with acid and enzymes
  15. Acid
    • pH 2
    • Parietal cells secrete hydrogen and chloride ions, which combine to make HCl
    • Acid kills bacteria and breaks apart cells in food
  16. Pepsinogen and HCl produce:
  17. Postive feedback
    Pepsin production activates more pepsinogen production
  18. Heartburn
    Acid reflux into esophagus
  19. Alkaline pancreatic juice
    Neutralizes acid chyme and its enzymes digest food
  20. Bile
    • Made in the liver and stored in the gall bladder
    • Emulsifies fat for attack by pancreatic enzymes
  21. Surface area of absorption is increased by:
    • Folds of the intestinal lining
    • Fingerlike villi
  22. Nutrients
    Pass across the epithelium and into blood
  23. Blood
    Flows to the liver where nutrients are processed and stored
  24. When diarrhea occurs:
    Too little water is reclaimed
  25. When constipation occurs:
    Too much water is reclaimed
  26. Specializations of the gut for herbivores:
    • Rumen
    • Reticulum
    • Omasum
    • Abomasum
  27. A healthy diet satisfies three needs:
    • Fuel to power the body
    • Organic molecules to build molecules
    • Essential nutrients (raw materials that animals cannot make for themselves)
  28. Main sources of dietary calories:
    • Proteins
    • Carbohydrates
    • Fats
  29. Basal metabolic rate (BMR)
    The energy a resting animal requires each day
  30. Metabolic rate
    The BMR plus the energy needed for physical activity
  31. Excess energy is store as:
    Glycogen or fat
  32. Undernourishment
    Not enough calories
  33. Malnourishment
    Missing essential nutrients
  34. Minerals
    Simple, inorganic nutrients usually required in small amounts
  35. Recommended Dietary Allowances (RDA)
    Excessive doses of Vitamin A, K, D, E and iron can be dangerous
Card Set
bio chapter 21
bio chapt 21 exam