amphibiansamphibians the first vertebrates to live on land
TRANSCRIPT
Amphibians
The first vertebrates to live on land.
Necessary adaptations for life on land
1. Legs to support weight of animal & to allow for movement
Necessary adaptations for life on land
2. Lungs and/or cutaneous breathing rather than gills
Necessary adaptations for life on land
3. Heart able to supply more oxygen.
Frog Anatomy
Important TermsDorsal:
Top
Ventral: Bottom
Anterior: Front / head
Posterior: Rear
Frog Anatomy
External Structures
Skin•mucous glands keep skin moist which is necessary for cutaneous respiration• some have glands that produce poisons or foul-tasting substances
oxygen from the air is drawn into a frog's body by the blood vessels that
lie close to the skin.
Eyes•eyes bulge providing protection from predators •has 2 eyelids–one protects from dust –nictitating membrane is
clear & protects under water
Tympanic MembraneThe eardrum of the
frog
Structures of the MouthTongue
attaches at front of mouth so it can flick out to capture prey
Vomarine Teeth2 large teeth in roof of
mouth that impale the prey
(food is swallowed whole)
Structures of the MouthGullet
Opening to the esophagus
GlottisOpening to the
trachea (windpipe)
Structures of the MouthEustachian TubesLead to the Tympanic
Membrane.
Internal NaresNostrals
Frog Anatomy
Internal Structures
Skeleton•Frog has a reduced skeleton (9 vertebrae & no ribs) •Pelvic girdle is adapted to absorb shock from jumping
BrainA larger cerebrum
enables frog to process more
sensory information; large
optic lobe for vision
Digestive System• Esophagus: Tube that
leads to the stomach• Stomach: First site of
chemical digestion, breaks down food
• Liver: Makes bile (aids in digestion)
• Gall bladder: Stores bile• Pancreas: Makes insulin
(aids in digestion)
Digestive System• Small Intestine (duodenum
and ileum): absorb nutrients from food
• Mesentery: Holds coils of the small intestine together
• Spleen: Part of circulatory system, stores blood
• Large Intestine: Collects waste, absorbs water
• Cloaca - "Sewer": eggs, sperm, urine and feces enter this area
Urogenital SystemCombination of the Excretory and Reproductive
systems – they are closely relatedCloaca is the collection cavity for feces, urine, eggs, & sperm - one opening for all these to exit.
Reproductive SystemEggs are not watertight so reproduction must
happen in water.Males produce sperm & females produce eggs, both in large numbers for external fertilization
Reproductive System
Reproductive System
External Frog Anatomy
Forelimb
Ventral
Anterior
Dorsal
Posterior
Hind limb
Foot
HandTympanic Membrane
External Nares
Eye
Nictitating Membrane
Forelimb
Ventral
Anterior
Dorsal
Posterior
Hind limb
Foot
HandTympanic
Membrane
External Nares
Eye
Nictitating Membrane
Structures of the MouthInternal Nares
TongueEustachian Tubes
Maxillary Teeth
Vomarine Teeth
GulletGlottisInternal Nares
Tongue
Eustachian Tubes
Maxillary Teeth
Vomarine Teeth
Gullet
Glottis
Kidneys
Fat Bodies Oviduct
OvaryCloaca
Fat Bodies
Kidneys
Testes
Cloaca
BladderBladder
Kidneys
Fat Bodies
Oviduct
Ovary
Cloaca
Fat Bodies
Kidneys
Testes
Cloaca
Bladder
Bladder
E-mail your dissection pictures to [email protected]
Please…• Get out your notes from
yesterday• Get out something to write
with• Put all belongings at the back
of the classroom!