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2.  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.

3.  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

4.  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

5.  All reptiles have two functionally separate
circulations.

6.  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

7.  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.

8.  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.

9.  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

10.  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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12.  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

13.  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.

14.  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)

15.  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

16.  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.

17.  Parthenogenesis
No 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

18.  Vocalization
During breeding season male is hostile that may
bark and worn other males to attract females
 Mating occurs after this