1. Amphibians

2. General Characteristics
Hindlegs for jumping
Webbed feet
Larvae aquatic and fish – like with gills
Adults terrestrial with lungs
Moist skin with mucous glands
Lack scales and claws

3. Classification Order Urodela – salamanders and newts
Order Anura – frogs and toads

4. Feeding Tadpoles filter feeders
Adults carnivores with tongue attached at the front for quick extension
Mouth to esophagus to stomach to small intestine to large intestine to cloaca where wastes are stored
Liver, gall bladder and pancreas secrete digestive enzymes

5. Respiration Larvae breathe through skin and gills
In adults, lungs developed with a blood supply through capillaries and folds to increase surface area
Mouth and skin also serve as gas exchange areas
Most carbon dioxide leaves through skin
Force air into lungs by buccal respiration (through mouth)

6. Circulation Double loop Three chambered heart
carries oxygen – poor blood from heart to lungs and takes oxygen – rich blood back to heart
second loop transports oxygen – rich blood to the body
Three chambered heart
Left atrium, right atrium, ventricle

7. Excretion
Kidneys filter wastes from blood
Excrete urine into cloaca

8. Response and Movement Tympanic membrane for hearing
Front and back legs are used in a variety of ways
Eyes large and protected from damage and kept moist by transparent nictitating membrane
Tympanic membrane for hearing
Well developed nervous and sensory system
Hearing vital to survival and reproduction
Behaviour to regulate body temperature
Hibernation – reduce metabolism during cold weather
Estivation – similar but during hot weather

9. Reproduction External fertilization
Eggs or sperm leave the body through the cloaca
Eggs covered with sticky substance to provide nutrients
Attaches eggs to underwater plants
Some amphibians show parental care