SUPPORT AND MOVEMENT

Support Systems in Animals

Support system in humans and animals is called SKELETON or SKELETAL SYSTEM

3 types of

skeletal systems

ENDOSKELETON

HYDROSTATIC SKELETONEXOSKELETON

ENDOSKELETON

• Inner Frame• Refers to the

set of bones or cartilages that is inside the body of vertebrates.

EXOSKELETON

• 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

Maintains body shape

Protects soft organs inside

body

Provides place for muscles in body to attach themselves

Enables limbs to move

FUNCTIONS OF ENDOSKELETON

Supports body weight

Maintains body shape

Protects soft tissues from

damage

Provides surface for muscles to attach

themselves

Allows movement

FUNCTIONS OF EXOSKELETON

HUMAN SUPPORT SYSTEM

Endoskeleton in humans consists of

206 bones

Backbone mainly supported by Pelvic

Girdle

Pelvic Girdle : strongest bone in human body

ANIMAL SUPPORT SYSTEM

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.

Support System of Land Vertebrate Animals

Support System of Land Vertebrate Animals

Pectoral Girdle

Pelvic Girdle

Birds : Have hollow bones and air spaces inside so that the body is lighter.Advantages of hollow bones :LighterRequires less calcium and phosphorous for its

formation.

Support System of Land Vertebrate Animals

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.

Support System of Aquatic Vertebrate Animals

The buoyancy of the water allows the size of the aquatic vertebrate animals to be bigger than that of land vertebrate animals.

Support System of Aquatic Vertebrate Animals

COMPARISON OF THE SUPPORT SYSTEMS IN LAND AND AQUATIC VERTEBRATES

SIMILARITIES

ENDOSKELETON

VERTEBRATE BONES ARE

FLEXIBLE

PECTORAL AND PELVIC GIRDLE

COMPARISON OF THE SUPPORT SYSTEMS IN LAND AND AQUATIC VERTEBRATES

SUPPORT IN LAND

VERTEBRATESPectoral and pelvic girdle support the

body weight

Big and strong

Big

DIFFERENCES

SUPPORT

SKELETON

PECTORAL AND PELVIC GIRDLE

SUPPORT IN AQUATIC

VERTEBRATESWater buoyancy

supports the body weight

Small and weak

Small

SUPPORT SYSTEM FOR INVERTEBRATES

Invertebrates are animals that do not have a backbone.

Its body is supported by :External skeletal system

(exoskeleton)

Body fluids (hydrostatic skeletons)

EXOSKELETON OF INVERTEBRATES

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

EXOSKELETON OF INVERTEBRATES

For insects, the exoskeleton is called cuticle.

Cuticle is made of chitin (hard and impermeable to water)

Cuticle prevent the insects from growing.

HYDROSTATIC SKELETONS OF INVERTEBRATES

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.

COMPARISON OF THE SUPPORT SYSTEMS IN LAND AND AQUATIC INVERTEBRATES

SIMILARITIES

EXOSKELETON

BODY FLUID

COMPARISON OF THE SUPPORT SYSTEMS IN LAND AND AQUATIC INVERTEBRATES

SUPPORT IN LAND

INVERTEBRATES

Soft bodies with external

shells

Hard and made of chitin, for

example, insects.

DIFFERENCES

SUPPORT

SKELETON

SUPPORT IN AQUATIC

INVERTEBRATES

Water buoyancy

Hard and made of calcium

carbonate, for example, crabs.

“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.