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