Amphibian Notes Frog Dissection

Challenges to living on land Amphibian - "double" life Movement to Land 3 major problems 1. Drying Out 2. Less support 3. Temperature Fluctuations

Characteristics of Amphibians Breathing: Tadpoles vs. Adult Mucous glands on the skin Webbed feet Cold-blooded Control metabolism estivation hibernation

Classification of Amphibians Tailless Amphibians (Order Anura) Ex: Frogs, Toads Visible Tailed Amphibians (Order Urodela) Ex: Salamanders, Newts Legless Amphibians (Order Apoda) Ex: Caecilians http://www.bio.sdsu.edu/pub/tod/herpetology/anurans/pics/hyla%20gratiosa%203.JPG http://www.caudata.org/axolotl/images/animals/salamandra_salamandra_1.jpg http://www.biology.ucok.edu/AnimalBiology/Chordata/Vertebrata/Amphibia/Caecilians2.jpg

Frogs: External Structures Head and Trunk Fused Skin: smooth, moist; mucous & poison glands, cutaneous respiration Hind legs Eyes Nictitating membrane—3rd clear eyelid Tympanic membrane

Frogs: Internal Mouth Structures Eustachian Tube Vocal Sacs Internal Nares Tongue Vomerine teeth Maxillary teeth Gullet Glottis

Frog: Digestive System Stomach Small Intestine Large Intestine Cloaca Accessory Organs Liver Gall Bladder Spleen Fat bodies

Other Systems of the Frog Skeletal System Respiratory System Tadpoles vs. Frogs Circulatory System Three Chambered Heart: 2 atrium 1 ventricle Nervous System

Other Systems of the Frog… Excretory System Kidneys Ureter Urinary Bladder Reproductive System External Fertilization Testes and Ovaries