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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

All reptiles have two functionally separate circulations.

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.

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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

VocalizationDuring breeding season male is hostile that may bark and worn other males to attract females

Mating occurs after this