1. Amphibians

2. Vertebrate Phylogenetic Tree
Feathers
Hair
Amniotic egg
Four limbs
Jaws

3. Characteristics of Amphibians
Phylum Chordata (vertebrates)
Class Amphibia
Live both on land and in water
Adaptations for living on land
Still need water to keep their skin and eggs wet

4. Three Groups Salamanders Frogs Caecilians Largest group of amphibians
Legless
Live in the tropics

5. Reproduction Amphibians need to return to the water to reproduce
Eggs do not have a shell to keep from drying out
Most frogs start their life as tadpoles

6. Metamorphosis Not all amphibians go through metamorphosis
Tadpoles undergo many changes to develop into adult frogs
Gills and lungs resorbed
Tail absorbed and legs are grown
Digestive, skeletal, nervous, and circulatory systems rearranged

8. External Anatomy Eye Mouth Forelimb Hindlimb Webbed foot
Tympanic membrane- ear drum

9. Internal Anatomy
Nervous system
Digestive system
Circulatory system

10. Nervous System
Brain
Spinal cord
Nerves

11. Digestive System Mouth Esophagus Stomach Small intestine
Large intestine
Cloaca
Liver- usually largest structure, three lobes
Detox materials and produces some digestive enzymes

12. Urogenital System

13. Circulatory System Heart
Dorsal aorta- large blood vessel along the back
Veins- carry blood back to heart
Arteries- carry blood away from heart