20587313 Biology Form5 Locomotion and Support

7/29/2019 20587313 Biology Form5 Locomotion and Support

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Biology form5Chapter 2 : Locomotion and support

2.3 Support in Plants

2.2 Appreciating a Healthy Musculoskeletal System

2.1 Support and Locomotion in Humans and Animals

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2.1 Support and Locomotion in Humans and Animals

Human Skeleton

Exoskeleton-enclosed the bodies of

arthropods (insects and

crabs)

-supports the important

internal organs and

protects the internal

structures from damage

-thin and flexible at joints

-on a process called

ecdysis, the insects shed

their skeleton to increase in

size

Endoskeleton-found in all vertebrates

-hardbskeleton of bones

are made up of phosphate

and calcium

-important to maintain thebody shape, supports the

soft body tissues and

protects the internal organs

from getting injured

-certain parts of

endoskeleton stores

minerals

Hydrostatic-consists of internal fluids in

the confined body cavity

-the fluid is held under

pressure in compartments

surrounded by muscles

-maintains the shape of

soft-bodied

organisms,such as hydra

sp, earthworm and sea

anemones

Skeleton

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Human Skeleton

Axial Skeleton

Appendicular

Skeleton

_____________The structure of a joint

How movement is

brought in a limb

The structure of a

muscleConsequences of impaired musculoskeleton

system on support and locomotion

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Human Skeleton Axial Skeleton

Skull Vertebral column Thoracic

The part of the skeleton that forms an imaginary line

down the back of the body is known as axial skeleton.

The bones that make up the axial skeleton are the skull,

the vertebral column (cervical vertebrae, thoracic

vertebrae, lumbar vertebrae, sacrum and coccyx),

sternum and ribs.

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-contains 22 bones

-protects the brain

(carnial bones)

-provides support forthe entrance ofthe respiratoryand digestive

systems (facialbones)

-Suture (immovablejoints that hold thebone whichmakes up the

skull firmly )



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The vertebral column is a series ofsmall bones that forms a flexible

structure and provides support. It runs

down the dorsal side of a vertebrate

animal. Each bone is known as a

vertebra.

1

2

4

3

1

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Human Skeleton


Cervical - composed of seven

vertebrae and forming the neck.

Thoracic - composed of twelve

vertebrae and joining to the ribcagetogether forming the thorax.

Lumbar composed of five

vertebrae. These are the biggest in

size.

Sacrum composed of five fused

vertebrae in adults. They may occur

as separate bones in youngchildren. They join with the hip bone

forming the pelvis.

Coccyx formed from the fusion of

two or four vertebrae. Sometimes

known as the tail bone.

Axial Skeleton

1

2

4

3

1

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Human Skeleton


Axial Skeleton

1

2

4

3

1

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Human Skeleton


Axial Skeleton

1

2

4

3

1

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Human Skeleton


Axial Skeleton

1

2

4

3

1

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Human Skeleton


-protects the heart

and lungs

-12 pairs of ribsmake up the sides

of the thoracic

cavity

-they articulatewith the twelve

vertebrae of the

thoracic region

Axial Skeleton

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Human Skeleton Appendicular Skeleton

The bones that make up the appendicular skeleton are scapula, clavicle or collar

bone, humerus, radius, ulna, tibia, femur, pelvic girdle and fibula.

Scapula - flat, triangular-shaped bone, that

forms the skeletal basis of the shoulder.

Humerus the bone of the upper arm, its

upper end articulates with the scapula to form

a ball-end-socket joint at the shoulder,

allowing movement in all directions.

Ulna longer bone of the forearm that

articulates with the humerus.

Radius flattened, slightly curved bone in the

hand.

Pelvic girdle provides connection betweenthe axial skeleton and the hind limbs.

Femur largest bone in the human body, its

lower end articulates with the tibia to form a

hinge joint at the knee.

Fibula shorter and smaller bone, found

along with the tibia, giving skeletal support to

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The structure of a joint

-cartilage (reduces friction is a shock

absorber, cushions the joint, protects

the bones from wearing away)

-synovial fluid (acts as a lubicant,

minimises the friction between the

ends of the bones) [email protected]


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-allow the bones to rotate in all directions

-allow the swinging of arms and legs in a

circular motion

-example:the hip joint between ferum and

the pelvic girdle, the shoulder joint

between the humerus and the pectoral

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-Also called knee joints

-found in the elbows, and phalanges of

toes and fingers

-allow the lower leg to swing back and

forth

-allow the movement of bones in one plate

-work like a hinge on a [email protected]


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How movement is brought in a limb

The movement of the forelimb is brought about by

the contraction and relaxation of a pair of

antagonistic muscles, namely the biceps and the

triceps.

The arm is flexed by the contraction of the bicep

muscles. The tricep muscles relax as the bicepmuscles become thicker and shorter. Contraction

of the bicep muscles pulls the ulna up thus

bending the arm at the elbow joint.

To straighten the arm, the tricep muscles contract

while the bicep muscles relax. Contraction of the

tricep muscles pulls the ulna down and arm is

straightened.

Tendon-tough, strong and inelastic strands of

dense connective tissues

-connects skeletal muscle to the bonesLigaments-holds the bones together

-tough sheets of elastic fibres

-connects bone to bone

-allows the movements and prevent the

dislocation of the joint during movement

Antagonistic pairs-a pair of muscles work together to allow

coordinated movement of skeletal joints.( contracts & relaxes)

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The structure of a muscle1 2 3

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Skeleton muscle(suchas biceps consists ofbundles of muscle fibres and

a large supply of nerves and

blood vessels.)

Muscle fibre (a single,

long cylindrical cell thatcontains many nuclei)

Myofibril (bundles ofsmaller units made muscle

fibre, made up of two types

of protein)

Actin & myosin(interaction of both proteins

cause muscle contraction)


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Consequences of impaired musculoskeleton


Osteoporosis is a disease where the bone tissue starts eroding, making the

bones brittle and prone to fractures. T is common in the elderly and women

after menopause.

Osteoporosis can be prevented by taking a diet rich in calcium, phosphorus

and vitamin D, regular weight-bearing exercise, and avoiding smoking andexcessive alcohol.

osteoporosis Muscular dystrophy Arthritis

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It is a genetic disorder of the muscle tissues caused by the lack of nourishment to

the affected muscles. It causes the muscles in the body to become very weak. The

muscles break down and are replaced with fatty deposits over time. Muscular

dystrophy is more common in males than in females. It is usually seen in children

between two to ten years old. Duchenne muscular dystrophy is the most common

form of muscular dystrophy, caused by an X-linked recessive gene.

Treatment-There is no known

treatment, medicine, or surgery to

cure muscular dystrophy or stop

the muscles from weakening. Thegoal of treatment is to prevent

deformity and allow the child to

function as independently as

possible.


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C f i i d l k l


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Arthritis is the inflammation of one or more joints characterised by swelling,

warmth, redness of the overlying area, pain and restriction of movement.

Is comprises more than 100 distinct conditions and can affect people at any

stage of life. The most common forms are osteoarthritis, rheumatoid arthritis and

gout.

Osteoarthristis is most common in older people where the top layer of cartilage

breaks down and wears away. Rheumatoid arthritis causes inflammation of the

synovial membrane of the joints in the hands, wrists, neck, jaw, elbows, feet and

ankles, which may cause damage to the cartilage and bone itself. Gout is

condition that results from deposition of uric acid in the joints.


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Earthworm

Locomotion

Grasshopper

Fish

Bird

Frog

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Earthworm-Invertebrate which do not have

exoskeleton, but uses body fluidto maintain a hydrostatic

skeleton.

-The movement of the earthworm

is aided by hydrostatic pressure

so that the body of the earthworm

can shorten, elongate andprotrudes forward.

-there are two pairs of muscle i.e.

circular and longitudinal muscles

that act antagonistically.

-contraction and retraction of

circular and longitudinal musclewill cause a peristalsis wave and

enables it to move forward.

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Earthworm

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GrasshopperGrasshoppers have an exoskeleton.

Muscle bundles on the inside, are attached to the exoskeleton. Across

the joints. The muscles work in that antagonistic pairs is known as theflexor and extensor muscles. The contraction results in the bending of

the joint and the relaxation results in the extending of the joint.

Antagonistic pairs allow movement of the appendage in both the

directions.

Grasshoppers have three pairs of legs. The body is supported on a

tripod of three legs in walking. The other three legs pull or push the body

forwards. The third pair legs are long with powerful muscles for jumping.The extensor muscles are attached to the tendons.

Before jumping, the rear legs are fully flexed. Energy is stored in the

elastic tendons caused by the contraction of both the flexor and the

extensor muscles.

During jumping, the flexor muscles relax and the extensor contract

causing the rear legs to straighten. The energy stored in the tendon

propels the grasshopper into the air. The grasshopper can jump 20 timesits body length.

Grasshoppers have a pair of wings. The wings are flattened extensions

of the exoskeleton. During flight, the wings of the grasshopper move

forwards and backwards, upwards and downwards through the air owing

to contractions of the flight muscles. This produces a lift by driving the air

downwards which in turn enables the grasshopper to lift off and [email protected]


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FishFish have a streamlined body, smooth and rounded

at the anterior part of the fish, and long and tapering

body towards the posterior end. This helps toovercome water resistance while moving in water.

Fish swim by contracting and relaxing a succession

of muscle blocks called myotomes. These muscle

contract and relax alternately on each side of the

body, starting at the head and progressing down

towards the tail.

The alternate contracting and relaxing of myotomes,which bends part of the body first towards the other

side, result in a series of waves travelling down the

fishs body. The rear part of each wave thrusts

against the water and propels the fish forward.

Fish have fins to overcome the instability in water

while swimming. The dorsal and the ventral fins are

useful in stabilising the fish as it swims, helping to

change direction quickly, or used with the other finsfor applying brakes. Paired pectoral and pelvic fins

help to overcome rolling and pitching by stabilising

the fishs body.

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BirdThe birds wing has a

curved shape called an

aerofoil. The air on theupper part has a lower

pressure than the air

moving over the lower

part. This pressure

difference makes the

lifting of the body possible

by the wing.

There are two pairs of

antagonistic muscles that

are evolved for flight. The

larger pair called the

pectoralis major contracts

for the downstroke. The pectoralis minor handles the upstroke, which needs far

less power.

Conversely, the contraction of the pectoralis major muscles moves the wing

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FrogFrogs make use of their long hind legs to effect several kinds of

locomotion such as jumping, hopping, swimming, burrowing, and

climbing. The long hind legs have well developed muscles to lift themoff the ground.

When the frogs are at rest, the long hind legs are folded into a Z

shape.

Frogs crawl by extending and retracting their fore and hind limbs.

During hopping, the extensor muscles contract rapidly, causing the

hind legs to straighten suddenly. A force is produced to push the frog

upwards and forwards.

Frogs land on their short forelimbs. The short forelimbs absorb theshock of impact. Most frogs can jump ten times their body length.

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Frog

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2 2 A i ti H lth


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2.2 Appreciating a Healthy

Musculoskeletal System

-A balanced diet - It is very important to have a diet rich in proteins to build musclesand calcium for strong teeth and bones. Fats and oils should be avoided.

-Good posture A good posture is to be maintained in all occasions and slouching

should be avoided. A good posture while perfoming certain tasks helps to ensure

that the body is always well-supported.

-Proper attire for daily activities Comfortable clothes and shoes should be worn

especially during long walks so that the flow of movement is not hindered.

-Exercise The right amount and the right kind of exercise are very important for a

healthy musculoskeletal system. The correct and safe exercise technique should be

practised. The wrong kind of exercise can cause serious injuries to the

musculoskeletal system. Appropriate precautions should be taken during vigorous

activities which can result in strains, sprains, dislocations and fractures.

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Aguatic plants

2.3 Support in Plants

Terrestrial plants

-To allow growth towards sunlight in order for photosynthesis to take

place-To allow leaves be placed in proper position for maximum absorption of

light

-To allow flowers be placed in a position that they can attract insects for

pollination

-To allow fruits be placed in strategic places for effective dispersal of

seeds

Test

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Aguatic plants

-Possesses features to help them stay afloat on water

-The natural buoyancy of the water helps the aquatic plants to float

-Consists of spongy tissue filled with air sacs which are known as aerenchyma

tissues. These tissues help the leaves and stems of the aquatic plants to float

on the surface of the water

Submerged Plants Floating plants

Air sacs

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They depend on the turgidity of thecells and other supportive tissues forsupport.

Parenchyma tissues store starch,

sugars and water. These cellsmaintain the turgidity of the plants togive support to the plant.

Collenchyma tissues support youngand herbaceous plants. These cellshave slightly thickened walls of

cellulose which give support to the leafor flower stalk and young stems.

Terrestrial plants

Herbaceous plant Woody plants Special

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-supported by sclerenchyma and xylem tissues

-Sclerenchyma tissues are composed of cell with secondary cell walls that are usually lignified

-Have thick, rigid and non-stretchable cell walls

-support the non-growing parts of plants

-divide into 2 types of sclerenchyma tissues: fibres (long, thin and straight. Found outside thevascular bundles.) sclereids (short, small and irregular-shaped. Found in fruits and seeds)


sclereidsfibres

1

2

Terrestrial plants

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During development ,the cell walls of

the xylem vessels and tracheid are

thickened with lignin which are

deposited during plants secondarygrowth. There are different types of

vessels.


1

2

Terrestrial plants

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Special structural adaptations for external support in some terrestrial plants

-roots come out from the lower part of the trunk and grow into the ground.

-provide support for the trees.

-roots are different from others.

-important in breathing and growing


Buttress root

thornsTendrils

Clasping root

Twining stem

Terrestrial plants

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Test

3. What is the tissue enclosed in the oval labeled C?Phloem Xylem Fibers Parenchyma

4. What is the function of the tissue represented in D?Transport water Transport food Storage Photosynthesis

What is the tissue represented in D?Parenchyma Chloroenchyma Collenchyma Hypodermis

1. What is the tisue represented in A?

Collenchyma Parenchyma Sclerenchyma

Epidermis

2. What is the tissue represented in B?

Parenchyma Collenchymal Sclerenchyma

Hyperdermis

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Thank You

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20587313 Biology Form5 Locomotion and Support

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Transcript of 20587313 Biology Form5 Locomotion and Support