Scientists believe other vertebrates evolved from BONY LOBE-FINNED fish
Scientific American; Dec 2005; Vol 293; p100-107
Moist, thin skin without scalesAquatic larva changes to terrestrial adultFeet without clawsRespiration with gills, lungs, skin, mouthClosed 2 loop circulationEctothermic (cold blooded)Eggs without shells or multicellular
membranes
LATIN meaning
KINGDOM _____________
PHYLUM ____________________________
SUBPHYLUM ___________________________
CLASS _______________________________
ORDER _____________________________
ANIMALIA
CHORDATA
VERTEBRATA “backbone”
AMPHIBIA “double life”
ANURA “without a tail”
Thin, moist skin – no scales
Mucous glands make it “slimy”
Camouflage- for protection
Some have poison glands
Body temperature is dependent on surrounding environment
FAT stored in FAT BODIES provides energy
Nictitating membrane
NO CLAWS
DIGESTIVE WASTE (feces) = _________________
Shared EXCRETORY & REPRODUCTIVE EXIT =
_____________________________(Urine & eggs or Urine & sperm)
ANUS
UROGENITAL PORE
OPENING SHARED BY EXCRETORY,REPRODUCTIVE, & DIGESTIVE =_____________Cloaca/Vent
Sperm and egg released at same time and place
Increases chances of fertilization
TONGUE attached at front not back like yours!
Connect earsto back of throat
GLOTTISOpening torespiratory
GULLETOpening to digestive
• Place frog with ventral side up
• Make a longitudinal cut starting between the hind legs and going anteriorly to the tip of the jaw
• Make lateral cuts behind front legs and in front of hind legs
• First cut through the skin; repeat the incisions through the muscle layer
Females may have black & white eggs that need to be removed to see the other organs.
Pericardial membrane surrounds heart
Mesentery holds intestines together and supports all organs.
Store fat for energy duringHibernationEstivationBreeding
PYLORIC SPHINCTER CONTROLS passage of food from stomach into duodenum (intestine)
STOMACH:
LIVER:
GALL BLADDER:
Makes acid and digestive enzymesStarts digestion (grinds up food)
Makes bileStores glycogenStores vitaminsProcesses toxins (including nitrogen wastes) for kidneys
Stores bile
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
Produces and stores new RBC’s and processes old worn out ones
SMALL INTESTINE
DUODENUMReceives trypsin and
bile; finishes digestion
ILEUMAbsorbs nutrientsVILLIIncrease surface
area
LARGE INTESTINE
Removes water from digestive waste;
concentrates feces
___________________ Gets rid of nitrogen waste made by cells
Nitrogen waste has different chemical forms:
___________ __________ _____________MOST TOXIC made from LEAST TOXIC
ammonia by liver needs the
least water to dilute
FISH HUMANS BIRDS, REPTILESAMPHIBIANS
EXCRETORY
AMMONIA UREA URIC ACID
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 uric acid (depending on type of animal)
Image from: http://step.sdsc.edu/projects95/Frog.Dissection/index.html
KIDNEYS- Remove nitrogen waste from blood and dilute it with water to make urine; osmoregulation
STORES URINE MADE BY KIDNEYS
LARVAE (Tadpoles)Excrete AMMONIA like fish
Adult frogs excrete UREA to conserve water
DIGESTIVEEXCRETORYREPRODUCTIVE
LUNGS:
GASEXCHANGE
BREATHING WITH LUNGS is called PULMONARY RESPIRATION
OVARIES Make eggs
Carries eggs to cloacaAdds jelly coating
MAKE SPERM
Grow legs; Lose tail2 chambers 3 chambers1 loop 2 loopsBreathe w/ gills lungs & skinExcrete ammonia excrete urea (gills & kidneys) (kidneys)
Have a LATERAL LINEBreathe with gillsExcrete nitrogen waste as AMMONIA (with gills & kidneys)
Have a 2 chamber heartHave a 1 loop circulatory system
3 chambered heart
Right atriumLeft atriumVentricle
Images from: http://www2.volstate.edu/msd/BIO/1020/Lab7ChordateII.htm
ADULT FROG: 3 chamber heart 2 loop system
TADPOLES & FISH: 2 chambered heart 1 loop system
MAMMALS DON’T
Sinus venosus
Atrium
Ventricle Conus arteriosus
BODYorgans
GILLS
Fish/Tadpole circulation
Sinus venosus
RIGHTAtrium
Ventricle Conus arteriosus
Lungs
Bodyorgans
LEFTAtrium
Frog circulation
BRAIN