The reptile
-
Upload
amy-dandrea -
Category
Education
-
view
545 -
download
2
Transcript of The reptile
The Reptile Body
Characteristics of Reptiles
Reptiles were the first vertebrates to live on land Scales keep moisture inside
Reptiles eggs DO NOT dry out on land Live in a variety of different habitats
Tropical forests, des\serts, oceans, rivers, and lakes Are NOT found in very cold regions because they are cold-blooded
Characteristics of Reptiles• All reptiles share the following characteristics– Bodies covered in scales – Clawed toes– Ectothermic (cold-blooded) metabolism– Lack feathers or any form of hair– An internal skeleton– A heart with a partially divided ventricle – Lungs– Reproduce Internally
• Amniotic eggs
Reptile Movement and Response
The following adaptations allow reptiles to live in dry environments A strong skeleton Claws legs positioned under the body highly developed vision
Since Reptiles are cold-blooded this limits their habitat range
Endoskeleton Reptiles have a strong skeleton made of
bone Most reptiles have two pairs of limbs
Snakes and some lizards lack legsLegs positioned under the body
allow reptiles to move faster and easier on land
Reptiles have toes with clawsUse claws for climbing and digging Enables reptiles to run quickly
over short distances
Sensory Systems: Vision Vision is an important sense
Rely on sight to detect predators and prey
Eyes of reptiles are very large and have movable eyelidsSnakes and geckos lack
movable eyelidsReptiles that are active at
night can see very well in the dark
Sensory Systems: Hearing Hearing is a very important
sense organ to reptiles Sound waves first strikes the
tympanum (ear drum) and are then transmitted to the inner ear Snakes lack a tympanum They detect ground vibrations
through the bones of their jaw
Sensory Systems: Jacobson’s Organ Reptiles sticks their tongues out to collect small particles
from the air The small particles come in contact with the Jacobson’s
Organ The Jacobson’s Organ is a specialized sense organ in the
roof of the mouth of many reptiles, it is sensitive to odors Used to “taste” the environment
Sensory System Snakes are able to detect heat
given off by warm-bloodied prey Use heat sensitive pits below
each eye The pits allow the snake to
detect the distance and direction of the prey
Body Temperature Control Reptiles are ectothermic
They CANNOT heat their own body by using their metabolism A reptile’s body temperature is mostly determined by the
temperature of its environment Reptiles may bask in the sun to warm up or seek shade to cool
down At very low temperatures reptiles slow down and may not be
able to function
Respiration and Circulation The following adaptations allow reptiles to have
more efficient respiration and circulation
1. Lungs with a large surface area
2. A heart that is almost completely divided into four chambers
Reptile Lungs Reptile lungs have many internal folds, which
gives the lungs a large surface area for oxygen exchange Strong muscles in the rib cage allow air to move in
and out of the lungs quickly, which increases lung efficiency
Reptile Heart The septum partly divides the ventricle into right
and left halves Enables a much better, but still incomplete,
separation of oxygen-rich and oxygen-poor blood Oxygen is delivered to the body cells more
efficiently in reptiles than in amphibians
Reptile Reproduction Reptile reproduction occurs through internal fertilization
Many reptiles are oviparous: the young hatch from eggs that are laid outside the mother’s body.
Some snakes are lizards are ovoviviparous: fertilized eggs remain inside the female’s body for a long time and hatch inside the female This protects the eggs from predators
Most reptiles DO NOT care for their young Alligators and crocodiles are an exception
Amniotic Eggs An amniotic egg contains both a water supply and
food supply Amniotic eggs are key to a reptile’s success as a
terrestrial animal They are watertight
Amniotic Egg Structure The shell and albumen protects
and cushions the embryo Also a source of nutrients
There are four membranes in the amniotic egg 1. Amnion- cushions the embryo 2. Yolk Sac- contains the embryo’s
main food supply, blood vessels attach here
3. Allantois- stores waste and is the embryo’s organ for gas exchange
4. Chorion- allows oxygen to enter the egg and carbon dioxide to leave the egg