Chapter 40 Amphibians

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Chapter 40Amphibians

• Section 2
• Characteristics of Amphibians

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Skin

• Respiration protection
• Moist and permeable to gas and water
• Mucous glands- supply lubricant that keeps the
  skin moist
• Skin also provides a foul-tasting secretion which
  protect frogs

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Skin

• Live in moist areas to avoid drying out
• If in desert, they burrow to survive drying out
• Affected by pollution- chemicals in water can
  affect amphibians
• Can serve as indicators of the health in an
  ecosystem

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Skeleton

• Strong internal skeleton (vertebrate, legs)
• Pectoral and pelvic girdles transfer bodys
  weight to the limbs
• In frogs, they have strong bones for jumping and
  landing

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Circulatory System

• Heart is separated into two loops
• Pulmonary circulation- carries deoxygenated blood
  from the heart to the lungs and back to the heart
• Systemic circulation- carries oxygenated blood
  from the heart to the body and back to the heart

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Circulatory System

• Three chambered heart
• All other terrestrial vertebrates also have a
  double loop circulatory pattern
• Allows for faster blood flow

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Respiration

• Larval amphibians respire (exchange carbon
  dioxide and oxygen) through their gills and skin
• Pulmonary respiration- respiration through the
  lungs
• Cutaneous respiration- respiration through the
  skin

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Digestive System

• Adults- carnivorous- eat insects, mice, snake,
  birds, other amphibians, etc
• Larva- herbivores- eat plants
• Pharynx ? esophagus ? stomach ? liver ?
  gallbladder ? small intestine ? large intestine ?
  cloaca

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Accessory Glands

• Liver produces bile- stored in the gallbladder
• Bile helps break down fat
• Pancreas secretes enzymes that help break down
  food

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Nervous System

• Olfactory lobes- sense of smell
• Cerebrum- behavior and learning
• Optic lobes- process information from the eyes
• Cerebellum- muscular coordination
• Medulla Oblongata- organ functions (heart
  respiration rate)

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Sense Organs

• Sight, smell, hearing
• Nictitating membrane- eyes covered by a
  transparent, movable membrane
• Tympanic membrane- eardrum
• Columella- small bone that extends between the
  tympanic membrane and inner ear

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REVIEW!!!

• Identify an advantage and a disadvantage to the
  permeability of amphibian skin?
• Explain how a frog uses positive pressure to move
  air into and out of its lungs.