Transcript Support & Movement

Support system in humans and animals is
called
SKELETON or SKELETAL SYSTEM
ENDOSKELETON
3 types
of
skeletal
systems
EXOSKELETON
HYDROSTATIC
SKELETON
ENDOSKELETON
EXOSKELETON
• Inner Frame
• Refers to the
set of bones
or cartilages
that is inside
the body of
vertebrates.
• Outer Frame
• Consists of
one layer of
hard skin or
shell derived
from
substances
like calcium
carbonate.
HYDROSTATIC
SKELETON
• Formed from
fluid pressure
in space that
is enveloped
by a
muscular
system.
Supports body
weight
Protects soft
organs inside
body
Maintains
body shape
Provides place for
muscles in body to
attach themselves
Enables limbs
to move
Supports body
weight
Protects soft
tissues from
damage
Maintains
body shape
Provides surface for
muscles to attach
themselves
Allows
movement
Endoskeleton in
humans consists of
206 bones
Backbone mainly
supported by Pelvic
Girdle
Pelvic Girdle : strongest
bone in human body
ANIMALS
Vertebrates
Land
Aquatic
Invertebrates
Exoskeleton
Hydrostatic
Skeleton
Entire weight is supported by its endoskeleton.
Skeletal system : bigger and stronger than that
of the aquatic animal vertebrate system.
Big land animals : Strong and big Pectoral and
Pelvic Girdles to support their body weight
Four-legged animals : Backbone either curve
upwards or downwards. Enables backbone to
withstand any heavy load acting on the animal.
Pectoral Girdle
Pelvic Girdle
Birds : Have hollow bones and air spaces inside
so that the body is lighter.
Advantages of hollow bones :
Lighter
Requires less calcium and phosphorous for its
formation.
Examples : Whales, dolphins
Smaller and lighter endoskeleton than land
vertebrates.
Pectoral and pelvic support that is smaller and
lighter.
Most of body weight is supported by buoyancy of
the water.
The buoyancy of the water allows the size of the
aquatic vertebrate animals to be bigger than
that of land vertebrate animals.
ENDOSKELETON
SIMILARITIES
PECTORAL
AND PELVIC
GIRDLE
VERTEBRATE
BONES ARE
FLEXIBLE
SUPPORT IN
LAND
VERTEBRATES
DIFFERENCES
SUPPORT IN
AQUATIC
VERTEBRATES
Pectoral and pelvic
girdle support the
body weight
SUPPORT
Water buoyancy
supports the
body weight
Big and strong
SKELETON
Small and
weak
Big
PECTORAL AND
PELVIC GIRDLE
Small
Invertebrates are animals that do
not have a backbone.
Its body is supported by :
External skeletal system
(exoskeleton)
Body fluids (hydrostatic
skeletons)
Exoskeleton consists of a layer of
hard skin or shell.
Examples of invertebrates with hard
outer skin :
 Crabs, spiders, prawns and
scorpions.
Examples of invertebrates with
hard shell :
 Snails, mussels
For insects, the exoskeleton is
called cuticle.
Cuticle is made of chitin (hard and
impermeable to water)
Cuticle prevent the insects from
growing.
Leeches, worms and octopus do not
have exoskeleton. Their bodies are
soft.
Use the body fluid (also known as
hydrostatic skeleton system) as
support system.
The body fluids exert a pressure on
their body walls to form a hydrostatic
skeleton.
EXOSKELETON
SIMILARITIES
BODY
FLUID
SUPPORT IN
LAND
INVERTEBRATES
DIFFERENCES
SUPPORT IN
AQUATIC
INVERTEBRATES
Soft bodies
with external
shells
SUPPORT
Water
buoyancy
SKELETON
Hard and made
of calcium
carbonate, for
example, crabs.
Hard and made
of chitin, for
example,
insects.
“That’s all, kids! Use this as an enhancement
material or review notes for the upcoming
MIDTERM exam in Science.”
There is another slideshow on SUPPORT
SYSTEM in PLANTS in our blogsite.