1. Frog Dissection

3. Scientists believe other vertebrates evolved from BONY LOBE-FINNED fish

4. Scientific American; Dec 2005; Vol 293; p100-107

5. TIK-TAALIK Intermediate between fish and early tetrapods
TIK-TAALIK
Intermediate between fish and early tetrapods
Fins have basic wrist bones and simple fingers
Earliest fish with a neck
Discovered by Neil Shubin and Ted Daeschler in 2004

6. AMPHIBIAN CHARACTERISTICS
Moist, thin skin without scales
Aquatic larva changes to terrestrial adult
Feet without claws
Respiration with gills, lungs, skin, mouth
Closed 2 loop circulation
Ectothermic (cold blooded)
Eggs without shells or multicellular membranes

7. http://users. erols. com/jkimball. ma

8. FROG ANIMALIA CHORDATA VERTEBRATA “backbone” AMPHIBIA “double life”
LATIN meaning
KINGDOM _____________
PHYLUM ____________________________
SUBPHYLUM ___________________________
CLASS _______________________________
ORDER _____________________________
ANIMALIA
CHORDATA
VERTEBRATA “backbone”
AMPHIBIA “double life”
ANURA “without a tail”

9. Thin, moist skin – no scales Mucous glands make it “slimy”
Camouflage- for protection
Some have poison glands

10. BREATHING THROUGH SKIN is called CUTANEOUS RESPIRATION
BREATHING THROUGH SKIN is called CUTANEOUS RESPIRATION

11. ECTOTHERMIC “cold blooded”
Body temperature is dependent on surrounding environment

12. HIBERNATION/ ESTIVATION
FAT stored in FAT BODIES provides energy
Images from:

13. Nictitating membrane (3rd eyelid) “swim goggles”
Image by: Riedell/VanderWal©2006
Nostrils = external nares

14. All tetrapods (amphibians, reptiles, birds, and mammals) have a middle ear with a tympanic membrane (= eardrum).
Image by: Riedell/VanderWal©2006

15. The major difference in the middle ear:
Amphibians, reptiles, birds have a single ear bone (= columella)
Mammals have three middle-ear bones

16. NO CLAWS
image from:

17. EXIT OPENINGS DIGESTIVE WASTE (feces) = ANUS UROGENITAL PORE
_________________
EXCRETORY & REPRODUCTIVE EXIT =
_____________________________
(Urine & eggs OR Urine & sperm)
ANUS
UROGENITAL PORE

18. EXIT OPENINGS VENT OPENING SHARED BY EXCRETORY, REPRODUCTIVE,
& DIGESTIVE =
________
VENT
Image by: Riedell/VanderWal©2006

19. What sex is it? Images from:

20. Image by: Riedell/VanderWal©2006

21. AMPLEXUS “firm embrace”
Sperm and egg same time and place
Increases chances of external fertilization
Image from:

22. TONGUE attached at front not back like yours!
Imagse from:
TONGUE attached at front not back like yours!

23. PHARYNX Muscular Back of throat Pulls food into digestive system
Image by: Riedell/VanderWal©2006

24. EUSTACHIAN TUBES Connect ears to back of throat
Image by: Riedell/VanderWal©2006
EUSTACHIAN TUBES Connect ears
to back of throat

25. GULLET Opening to digestive system GLOTTIS Opening to
Image by: Riedell/VanderWal©2006
GULLET
Opening to
digestive
system
GLOTTIS
Opening to
respiratory system

26. MAXILLARY & VOMERINE TEETH
Image by: Riedell/VanderWal©2006
MAXILLARY & VOMERINE TEETH

27. INTERNAL NARES Allows frog to breathe with mouth closed!
Image by: Riedell/VanderWal©2006
Allows frog to breathe
with mouth closed!

28. Cut through skin first Then abdominal muscle Watch for squirting!
Image from
Cut through skin first
Then abdominal muscle
Watch for squirting!

29. CUTANEOUS RESPIRATION
Image by Riedell/VanderWal©2006
LOTS OF BLOOD VESSELS
for gas exchange
CUTANEOUS RESPIRATION

30. If yours looks like this . . . trade for a new frog
OVARY-
Make eggs
If yours looks like this . . .
trade for a
new frog
Image by Riedell/VanderWal©2006

31. FAT BODIES Store fat for energy during: Hibernation Estivation
Breeding
Image by Riedell/VanderWal©2006

32. LIVER Make bile to break down fats Store glycogen Store vitamins
Process toxins
(including
nitrogen waste
for kidneys)
Image by Riedell/VanderWal©2006

33. STOMACH Add acid Start digestion Grind/mash food
Image by Riedell/VanderWal©2006

34. GALL BLADDER Storage sac under liver Stores bile made by liver
Used in small
intestine
Image by Riedell/VanderWal©2006

35. PANCREAS

36. Pancreas (enlarged)

37. PANCREAS: Makes TRYPSIN, INSULIN, GLUCAGON
TRYPSIN- breaks down proteins
INSULIN- tells cells to store glucose from
bloodstream as glycogen
GLUCAGON- tells cells to release stored
glucose to blood stream

38. Mesentery holds intestines together
Image by Riedell/VanderWal©2006
Mesentery holds intestines together

39. INTESTINE SMALL INTESTINE LARGE INTESTINE Split up intestine functions
Image by Riedell/VanderWal©2006

40. SMALL INTESTINE Bile/trypsin added Finish digesting Absorb nutrients
VILLI-increase surface area for
more absorption
Image by Riedell/VanderWal©2006

41. LARGE INTESTINE Removes water from feces Collects/concentrates
digestive waste
Image by Riedell/VanderWal©2006

42. SMALL INTESTINE DUODENUM- Add bile/trypsin Finish digestion ILEUM-
Absorb nutrients
Image by Riedell/VanderWal©2006

43. CLOACA Shared collecting space for DIGESTIVE EXCRETORY REPRODUCTIVE
SYSTEMS
Image by Riedell/VanderWal©2006

44. STOMACH What’s for lunch? Cut open your stomach
Image by Riedell/VanderWal©2006

45. STOMACH RUGAE- Rough folds inside stomach allow expansion
help to break down food
Image by Riedell/VanderWal©2006

46. CONTROLS passage of food from stomach into duodenum (intestine)
PYLORIC SPHINCTER
CONTROLS passage of food from stomach
into duodenum (intestine)

47. SPLEEN BLOOD CELL FACTORY Makes, stores, processes worn out
red blood cells
Image by Riedell/VanderWal©2006

48. 10 Body Systems : ___________ __________ _____________ EXCRETORY
___________________
Get rid of nitrogen waste made by cells
Nitrogen waste has different chemical forms:
___________ __________ _____________
MOST TOXIC made from LEAST TOXIC ammonia by needs the least liver water to dilute
FISH HUMANS BIRDS, REPTILES
AMPHIBIANS
EXCRETORY
AMMONIA
UREA
URIC ACID

49. ALL WASTE is NOT THE SAME!
DIGESTIVE waste- left over from undigested food travels through digestive system
leaves through digestive system as feces
EXCRETORY waste- (Also called NITROGEN WASTE) made by cells from break down of proteins
travels through blood stream
leaves through excretory system as
ammonia, urea, or uric acid

50. Diagram by: Riedell

51. KIDNEYS-
Remove nitrogen waste from blood and dilute it with water to make urine;
Osmoregulation
Adult frogs excrete as UREA TO CONSERVE WATER
Image by Riedell/VanderWal©2006

52. URINARY BLADDER STORES URINE MADE BY KIDNEYS LARVAE (Tadpoles)
Excrete AMMONIA like fish
Adult frogs excrete
UREA to conserve water
Image by Riedell/VanderWal©2006

53. CLOACA Shared collecting space for DIGESTIVE EXCRETORY REPRODUCTIVE
SYSTEMS
Image by Riedell/VanderWal©2006

54. OVARIES
Make eggs
Image by Riedell/VanderWal©2006

55. Carry eggs to cloaca Add jelly coating
Image from:
Carry eggs to cloaca
Add jelly coating

56. OVARY without eggs
Image by Riedell/VanderWal©2006

57. TESTES-makes sperm VAS DEFERENS-tubules that carry sperm to cloaca
Image by Riedell/VanderWal©2006

58. AMPLEXUS “firm embrace”
Sperm and egg same time and place
Increases chances of external fertilization
Image from:

59. INDIRECT DEVELOPMENT Grow legs; Lose tail 2 chambers  3 chambers
Grow legs; Lose tail
2 chambers  3 chambers
1 loop  2 loops
Breathe w/ gills  lungs & skin
Excrete ammonia  excrete urea
(gills & kidneys) (kidneys)

60. ENDOCRINE SYSTEM THYROID GLAND makes THYROXIN to control heart rate,
THYROID GLAND
makes THYROXIN to
control heart rate,
metabolism, and
METAMORPHOSIS

61. Ways tadpoles are like fish
Have a LATERAL LINE
Breathe with gills
Excrete nitrogen waste as AMMONIA (with gills & kidneys)
Have a 2 chamber heart
Have a 1 loop
circulatory system

62. Pericardial membrane around heart Mesentery holds intestines together
image from:
Pericardial membrane around heart
Mesentery holds intestines together

63. LUNGS: GAS EXCHANGE Image by Riedell/VanderWal©2006

64. BREATHING WITH LUNGS is called PULMONARY RESPIRATION
BREATHING WITH LUNGS is called PULMONARY RESPIRATION
Frogs PUSH AIR INTO LUNGS = POSITIVE PRESSURE

65. Larvae breathe with GILLS

66. Image by Riedell/VanderWal©2006
HEART
3 chambers
2 loops

67. HEART 3 chambered heart Right atrium Left atrium Ventricle
Image from:

68. TADPOLES & FISH: 2 chambered heart 1 loop system ADULT FROG:
Images from:
TADPOLES & FISH: chambered heart
1 loop system
ADULT FROG:
3 chamber heart
2 loop system

69. MOST vertebrates have nuclei in their RBC’s
MAMMALS DON’T
RBCs’ image from:
Human RBC image from:

70. Conus arteriosus FISH CIRCULATION Sinus venosus   Atrium GILLS
BODY organs   
Atrium
GILLS  
Conus
arteriosus
Ventricle 
FISH CIRCULATION

71. Conus arteriosus FROG CIRCULATION Sinus venosus    Body organs  
RIGHTAtrium
LEFT Atrium 
Lungs      
Conus
arteriosus 
Ventricle 
FROG CIRCULATION

72. Conus arteriosus FROG CIRCULATION Sinus venosus    Body organs  
RIGHTAtrium
LEFT Atrium 
Lungs      
Conus
arteriosus 
Ventricle 
FROG CIRCULATION

73. SYSTEMIC CIRCULATION LUNGS = Pulmonary Kidneys = renal
Kidneys = renal 
Heart = coronary 
Liver = hepatic 

74. BRAIN