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Reptilian lungs are better developed than amphibians
Muscular ribs help them expand the chest cavity as we do to draw in the air
Nostrils allow them to bring in air while their mouth is closed
Snakes only have one long, lung that fits in their bodies.
Snakes also have a tube that projects out of the mouth when the snake is swallowing so that it can breathe and swallow at the same time
The ribs of turtles attached to their shells which prevent movement of body wall
They exhale by contacting muscles
More efficient circulatory system, higher blood pressure
All reptiles have at least an incomplete separation of the ventricles
Still incomplete separation of oxygen-rich and oxygen-poor blood
Crocodilians have two completely separated ventricles
Reptiles regulate their body temperature with in a narrow range, between 25-37
Behavioral and physiological activities to regulate temperature.
lizards absorbs heat by conduction.
Panting which releases heat through evaporative cooling
Reptiles basking in sun and warm up quickly.
Chromatophores also aid in temperature regulation.
In winter, individuals may migrate to a common site called a hibernaculum.
Larger cerebral hemisphere
than the amphibians
Optic lobes and the cerebellum
are also large
Increased reliance on vision
More refined co-ordination of
muscle functions.
Vision - dominant sense
In lizards eyes are movable while in snakes permanent transparent covering is present.
Hearing - no obvious external ear
Not deaf - have internal ears
No obvious response to aerial sounds
Sensitive to vibrations carried in ground
Olfaction important, but not in nostrils
Blind-ending pouches called as Jacobson’s pouches.
These pouches open in secondary palate through mouth cavity.
Tongue carries scent
particles to organ.
Behavioral changes helps to regulate temperature and conserves water
During day, nocturnal habitats and avoiding hot surfaces reduce water loss
In water availability, reptiles store large water quantities in lymphatic spaces
Kidneys is more advanced in reptiles called metanephric.
Blood-filtering units called as nephrons are present.
Kidney lack loop of Henley, it unable to produce liquid urine more concentrated than their body fluid.
Kidneys produce urine in the form of uric acid
Urine is either passed out directly through the cloaca, or stored in the urinary bladder where water is further reabsorbed
Uric acid crystallizes when concentrated, and is eliminated as a white paste (like birds)
Most reptiles are oviparous Female lays eggs that hatch outside her body To break out a hatchling uses a special tooth
which is lost soon after Others are ovoviviparous Female carries the eggs in her body
throughout development
Young are born live
Internal fertilization
A pair of ducts delivers sperm into cloaca of female
Male inserts penis into female’s cloaca
Female’s body coats the embryos in protective shell, with membranes and yolk sac.
ParthenogenesisNo male found higher reproductive bisexual population
Head-bobbing
Displays by some male lizards reveal bright patches of colors on the throat.
Tail waving
It is performed by male running chin along female