Amphibian Anatomy
Herpetoculture
Pensacola Jr College
Anatomical
Systems:
w Integumentary system (skin
and surface glands)
w Skeletal system
w Digestive system
w Respiratory system
w Circulatory system
w Urogenital system
Integumentary
system
w Amphibian functions:
Sensory organ
Protection
Water / salt balance
Sex recognition
Reproduction / raising young
Respiration
Temperature regulation
Vertebrate Skin -
Histology
Frog skin (low
power)
Frog skin (high
power)
Amphibian
Epidermis Specializations:
w Outer layer thin
respiration
w Blood vessels near surface
w Molting
w Claws not present or made of
looose keratin
Amphibian Dermis
Specializations:
w High amount of blood vessels
w Caecilians and salamanders
inner layer of dermis tightly linked to connective tissue and muscle underneath
w Frogs/toads loose skin
Amphibian Glands
w Mucous glands
Watery to viscous mucous
Keep skin moist
w Granular glands
Milky toxic solution
w Tubular glands
Flush dirt from nostrils
w Hatching glands
Dissolves egg covering
Amphibian
pigmentation:
w Chromatophores = pigment
cells in dermis
w Allows protection from sun,
predators, and species / sex recognition
w Color changes are due to
changing pigments within chromatophore cells
Skeletal System
w Amphibian skull simple,
fewer bones than fish, low ossification on top
w Vertebrae modified for
terrestrial life
Caecilians up to 250
Urodels 30 to 100
Anurans usually 10
Skeletal System
(contd)
w First true sternum
w First limbs
Requires pectoral and pelvic
girdle development
Weak in aquatic species
Strong in terrestrial
species
Urodel Skeleton
Anuran Skeleton
Digestive System
w Muscular protrusible tongue
w Mucus glands produce sticky
substance for coating tongue
w Small (or no) teeth
Pedicle fused to bone of
upper or lower jaw or bones of upper mouth
Connective tissue joint
Enamel or durodentine crown
Tooth structure
Digestive System
(contd)
w Larval forms are herbivores
elongated gut
w Adult forms are carnivores
shortened gut
w Extreme contraction occurs
during metamorphosis
w Cloaca present general
opening for voiding and repro
Frog digestive
tract
Respiratory System
w Cutaneous respiration (skin)
w Buccopharyngeal respiration (mouth
and throat)
w Gills (in larvae and some
aquatic adults)
w Lungs (in most adults)
Amphibian Gills
w Larvae have up to 3 pairs
w In salamanders they
disappear in metamorphosis if gills are lost
w In anurans they become the
eustacian tube in metamorphosis
Amphibian Lungs
w Air > pharynx >
trachea > two bronchi > paired lungs
w Trachea/bronchi have
cartilage rings for strength
w Lungs are simple membrane
sacs with pockets of alveoli and blood vessels
w Larynx for vocalizations
Circulatory System
- larvae
w Similar to fish, ventral
aortae carry blood from heart to gills, dorsal aortae from gills to body
tissues, veins back to heart
Circulatory System
-adult
w Deoxygenated blood to sinus
venosus to right atrium to ventricle
w Deoxygenated blood separated
by spiral valve > pulmonary arteries
w Oxygenated blood returns to
heart in pulmonary veins
(contd)
w Oxygenated blood to left
atrium to ventricle
w Oxygenated blood seperated
by spiral valve into conus arteriosus, pressurized, then sent into ventral
aorta to body
Amphibian Heart
Red Blood Cells
w Carry oxygen and carbon
dioxide in the blood
w Formed primarily in the
spleen
w Contains hemoglobin
w Maintains nucleus in
amphibians
w Life span about 100 days