Chp. 8 Support and Movement (1)

7/30/2019 Chp. 8 Support and Movement (1)

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All living things needs support system to

support their soft body tissues.

There are 3 types of support system:a) Exoskeleton (external skeleton)

b) Hydrostatic skeleton

c) Endoskeleton (internal skeleton)


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SUPPORT SYSTEM

Humans Animals

Endoskeleton

Vertebrate Invertebrates

(land & aquatic)

Land

endoskeleton Exoskeleton

Aquatic

endoskeleton

Water buoyancy

Hydrostatic

skeleton


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Endoskeleton (internal skeleton)

All vertebrates have endoskeletonFunctions:

i) Supports body weight and maintains the

shape of the bodyii)Protects soft tissues and internal organs

iii)Enables movement

iv)For attachment of muscles


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Human

i) Supported by endoskeleton (206 bones)

ii) These bones are group into axial skeleton( the trunk of the body) and the appendicle

skeleton (the limbs)

iii) Backbones is made up of 33 smallerbones called vertebrae, joined by cartilage.

iv) Leg bones and ribs are filled with marrow

v) Weight of the body is mainly supported by

the pelvic girdle.


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Support in animals

A) Land vertebrates

Land vertebrates like rhinoceros, elephants,

and horses have big and strong girdles to

support their body weight.

B) Aquatic vertebrates

Aquatic vertebrates have endoskeletons that do

not provide much support.

They have small and weak pectorals and pelvic

girdles, therefore their body weight is supported

by water buoyancy / up thrust.


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Exoskeleton (external skeleton)

made up of a hard outer skin or shell.

Supports the weight and maintains the

shape of the body.

Protects soft tissues and organs.

Owned by some invertebrates e.g. insects,

snails, scorpions, crabs, prawns,

centipedes.


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Hydrostatic skeleton

Consists of a muscular wall enclosing the

body cavity filled with fluid

The body fluid exert pressure at all directions.


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SUPPORT AND


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SUPPORT AND

MOVEMENT

IN PLANTS

Aquatic

plantsLand plants

Water

buoyancy

Woody

plants

Herbaceous

plants

Woody

tissue

Turgidity

of cells


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Aquatic plants

~ supported by up thrust or buoyancy of water.

~ have stems with large air space which makes itvery light. e.g. elodea, hydrilla.


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~ some have large leaves floating on water.

e.g. water lily, lotus.


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Land plants consist of woody and non-

woody plants (herbaceous)

Woody plants

~ supported by woody tissues (xylem tissue)

e.g. durian tree, casuarinas tree, rambutan

tree.~ additional support; buttress root, prop or

support root


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Herbaceous plants or non-woody plants

~ supported by water turgidity or pressure in

cells.

e.g. maize, paddy, mustard, cabbage.

~ the water exerts pressure in all directions

making the cell firm and turgid.

idi i h l d


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~water turgidity gives the plants support and

shape.


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~additional support; by climbing on other plants

to get space and sunlight.

E.g. by using tendrils, clasping roots, thorns,

twining steams.


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S i l t t bl i t


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Special support systems enable organisms to

survive.

e.g. a) if a whale is put on land, its skeleton will

collapse because its body weight is too

heavy for its skeleton to support.

b) If an aquatic plant is taken out of water, itwont stand upright.

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Chp. 8 Support and Movement (1)