1. Amphibians

2. What are amphibians? Vertebrates Tetrapods (“four feet”) Ectothermic
“both ways of life”
Special amphibious traits:
Respiration through skin
Some amphibians are lung-less
Metamorphosis

3. Amphibian Orders
Order Urodela
Order Anura
Order Apoda

4. Order Urodela Includes salamanders & newts
Have elongated bodies with a tail & four limbs 
Smooth, moist skin for cutaneous respiration
Less able to stay on dry land than anurans

5. Order Urodela Size from a few centimeters long to 1.5 meters
Nocturnal when live in drier areas
Lay eggs in water or damp soil
Some bear live young
May or may not go through tadpole stage (some hatch & look like small adult)

6. Order Anura Both terrestrial & freshwater species
Tadpole with tail, gills, & two-chambered heart
Adults without a tail, four limbs, & lungs
Frog skin smooth & moist for cutaneous respiration, while toads is rough & warty (poison glands)
Long hind limbs for jumping
Long, forked tongue hinged at front of mouth

7. Order Apoda Includes caecilians
Tropical, burrowing, worm like amphibians
Legless
Small eyes & often blind
Eat worms & other invertebrates
Average length 30 centimeters, but can grow up to 1.3 meters
Internal fertilization
Female bear live young

8. Feeding
Larvae: mostly herbivores
Adults: mostly carnivores

9. External Amphibian Anatomy
External nares
Tympanic membrane – cover ear
Nictitating Membrane – transparent eyelid
Upper and lower eye lid
Trunk
Head
Forelimb
Hindlimb

10. External nares
Tympanic membrane
Nictitating Membrane
Upper and lower eye lid
Trunk
Head
Forelimb
Hindlimb

11. Other external features
Webbed feet
Lack of claws
Layout of the “hands” can differ

12. Skeletal System Very similar layout to human skeleton
Head, trunk, limbs
Lack of rib cage

13. Skeletal System Skull Scapula Radioulna Humerus Vertebrae Tibiofibula
Femur
Tarsus
Metatarsus
Carpus
Metacarpus
Phalanges
*Urostyle

14. Skeletal System Skull Scapula Radioulna Humerus Vertebrae Tibiofibula
Femur
Tarsus
Metatarsus
Carpus
Metacarpus
Phalanges
*Urostyle

15. Muscular System Submaxillary Control of the Forelimbs: Obliques
Deltoid
Latissimus dorsi
Pectoralis
Obliques
Recuts abdominus
Linea Alba
Within Hindlegs:
Gastrocnemius
Triceps femoris

16. Muscular System

17. Muscular System

18. Digestive System
Tongue sticky, forked, & hinged at front of mouth so can be extended out to catch insects
Can pull eyes inward to help swallow food
Two, sharp, backward-pointing  vomerine teeth in roof of mouth help prevent prey from escaping
Maxillary teeth line the edge of the upper jaw

19. Digestive System
Alimentary canal (mouth, esophagus, stomach, small & large intestines, and cloaca) is where food is digested, absorbed & wastes eliminated
Stomach breaks down food
Pyloric sphincter muscle controls movement of food from stomach into first part of small intestine called duodenum

20. Digestive System Small intestine Accessory Organs:
First region: duodenum
Held together by mesentery
Accessory Organs:
Liver makes bile to digest fats
stored in gall bladder
Pancreas

21. Digestive System Wastes collect in large intestine
Move into cloaca along with eggs, sperm, & urine until they leave body through the anus

22. Digestive System

23. Digestive System

24. Respiratory System Differs between larvae and adult
Larvae: use gills and skin
Adult: lungs, some skin
Many salamanders have no lungs
Glottis – connection between the nose and the bronchii
Bronchii – connect glottis to lungs

25. Respiratory System

26. Circulatory System
Need more oxygen to burn increased amount of food needed to live on land
Spleen
More complex circulatory system
Double loop blood circulation
pulmonary from heart to lungs
systemic from heart to rest of body

27. Circulatory System
3 chamber heart
Left atrium
Right atrium
Ventricle

28. Circulatory System
Anterior vena cava - from anterior portion of body to heart
Posterior vena cava – from posterior portion of body to heart
Sinus venosus – both vena cava join to enter heart (right atrium)
Blood moves from right atrium to ventricle
From ventricle to lungs through the pulmonary arteries

29. Circulatory System
Blood moves from lungs back to the heart through the pulmonary veins
Pulmonary veins empty into the left atrium
Left atrium pumps into ventricle.
Ventricle leads to conus arteriosus
Conus arteriosus – large artery leading from heart to the body

30. Circulatory System

31. Nervous System
Relatively well developed
Brain is larger

32. Nervous System Olfactory lobes
Cerebrum behind olfactory lobes controls muscles
Pineal Gland - produces hormones
Optic lobes
Cerebellum controls balance & coordination
Medulla oblongata controls heart rate & breathing
Cranial nerves connect brain & spinal cord, while spinal nerves branch off the spinal cord to muscles & sensory receptors

33. Brain of the frog

34. Excretory System Kidneys – separate liquid waste from blood
Urinary Ducts  bladder  cloaca
On the kidneys: Adrenal Gland
Produces adrenaline

35. Reproductive System External fertilization Seasonal – spring
Females lay eggs in water
Males deposit sperm over eggs

36. Reproductive System Male: Female: Testes Seminal vesicles Ovaries
Oviducts

38. Other adaptations Dormancy during unfavorable environmental conditions
Hibernate during cold months
Many fat bodies throughout abdomen for energy during hibernation

39. Sexual Dimorphism
Physical characteristics differ between male and female
“Hands” of frogs are different between male and female
Male: larger “thumb”
Males: vocal sacs
Mating calls
Show dominance

40. Frog Dissection

41. Day 1: External Anatomy

42. Day 1: Pre lab quiz Group assignments External anatomy of the frog
Put your name on an index card
I will pick 2 or 3 pieces of paper for each group
The person you are picked with is your lab partner.
External anatomy of the frog
Sketch all external anatomy
Open mouth and sketch/label
After the external anatomy: frog metamorphosis activity

43. Growth and Development
Larva
Metamorphosis
Adult

45. Day 2: Internal Anatomy

46. Day 2:
Internal Anatomy
Open up the frog and observe/sketch each system
Sketch overall internal structure
Be sure to notice:
Digestive system
Urogenital system (kidneys with reproductive organs)
Respiratory structures