Support and MovementSupport and Movement

Biology

14.2 Support in mammals

in mammals

skeletonskeleton muscularmuscularsystemsystem

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Why do organisms need a skeleton?

What are skeletal tissues?

Two parts of skeleton

Joints and degree of movement

What is skeletal muscles?

How is movement achieved?

How are plants supported?

Multiple choices

Why do organisms need a skeleton? Mammals have endoskeletons

•for support

•for producing blood cells

Do you know what is the deficiency disease of calcium?

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Why do organisms need a skeleton?

•for movement

•for protection

Lungs

Heart

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Why?

•for storage of minerals

CaCa2+2+ CaCa2+2+

Why do organisms need a skeleton?

If the bone is immersed in an acidic solution for about 2 days, what will happen?

acid

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Summary

The mammalian skeleton is important in support, for attachment of muscles and functioning as a lever for movement, in protecting internal organs, in producing blood cells and in storage of calcium.

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What are skeletal tissues?

The skeletons are made up of bones and cartilages.

Transverse section of a compact bones

?

Structure of cartilage

Which one contains more mineral salts?

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The skeleton The skeleton Skeleton consists of :

• found between bones

• softer• reduces friction during movement

bones cartilage• hard• made up mainly of mineralse.g. calcium phosphate, calcium carbonate

What are skeletal tissues?

Cartilage

Spongy bone containing red bone marrow.

Compact bone

Cavity containing yellowyellow bone marrow

What is the use of the bone marrows?

What is the use of the bone marrows?

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What are skeletal tissues?

If my bones are burnt, it will become brittle.

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AxialAxial skeletonskeleton

Two parts of skeleton

Appendicular Appendicular skeletonskeleton

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Two parts of skeleton

Appendicular skeletonAppendicular skeleton• Pectoral girdles

• Pectoral limbs

• Pelvic girdles

• Pelvic limbs

Axial skeletonAxial skeleton• Skull• Sternum• Ribs• Vertebral

column

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Correct Posture to Prevent Injury

•Plant your feet firmly - get a stable base. •Bend at your knees - not your waist. •Tighten your abdominal muscles to support your spine. •Get a good grip - use both hands. •Keep the load close to your body. •Use your leg muscles as you lift. •Keep your back upright, keep it in its natural posture. •Lift steadily and smoothly without jerking. •Breathe - If you must hold your breath to lift it, it is too heavy.

DO NOT...

•Lift from the floor.

•Twist and lift.

•Lift with one hand (unbalanced)

•Lift loads across obstacles.

•Lift while reaching or stretching.

•Lift from an uncomfortable posture.

•Don't fight to recover a dropped object.

•Don't hold your breath while lifting - GET HELP.

Muscles are attached to Muscles are attached to bones through tendonsbones through tendons

The muscular systemThe muscular systemmuscular system• many different

sets of muscles• the two ends of

each muscle are attached to the limb bones through tendons

tendons• tough sheets

of inelastic fibres

• allow muscles to control the way bones move

Joints and degree ofmovement

1. Hinge joints

Hinge joints allow movement in one plane.

• Synovial Joint

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Joints and degree ofmovement2. Ball-and-socket joints

How many planes of movement do ball-an-socket joints allow?

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Joints and degree of movement 2. Ligaments are tough and they prevent dis

location of a joint during movement.pelvic girdle

ligaments

femur

cartilage

synovial joint

synovial membrane

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What are skeletal muscles? Muscle attached to the skeleton. Muscle cells with lots of proteins fibres Muscles work together with bones to give support and movement to ma

mmals.

In aerobic respiration:In aerobic respiration:

In anaerobic respiration:In anaerobic respiration:

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Muscles contract powerfully—ie. They work by PULLING. Do you think muscles can stretch themselves—and thus work by PUSHING?

Support in mammals

in mammals

skeletonskeleton muscularmuscularsystemsystem

The muscular systemThe muscular systemMuscles as part of the support system

If the forces of the muscles acting on both sides of two adjacent bones are balanced

bones will be kept in bones will be kept in the same positionthe same position

A skeleton falls downif let loose because nothing joins the bones together

Skeleton without muscles………..

give no support !!

How is movementachieved? 1. Tendons are tough and they connect mus

cles to bones.muscle

tendons

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2. Biceps and triceps are antagonistic muscles involved in the movement of the forearm. They work in pairs and in opposing directions.

ContentsHow is movementachieved?

3. Contraction of biceps (flexor) bends the forearm while contraction of triceps (extensor) straightens the forearm.

triceps relaxes

biceps contracts

triceps contracts

biceps contracts

ContentsHow is movementachieved?

ContentsHow is movementachieved?

4. Bone act as levers during movement. Movable joints act as the fulcrum. Concentration of muscles creates the effort.

contraction of biceps (effort)

hand (load)

elbow joint

(fulcrum)

ContentsHow is movementachieved?

How are plants supported?

1. Support in young plants or non-woody parts of plants is contributed mainly by turgidity of the thin-walled cells in the cortex and pith.

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14.3 Support in plants

in plants

Turgidity of cells Turgidity of cells For For nonnon-woody -woody

plantsplants

Hardness of thick- Hardness of thick- walled cells in walled cells in woody plantswoody plants

Turgidity of cellsTurgidity of cellsInside stem of herbaceous plants-(non-woody)

water potential of living cells

water potential of

xylem >

water move from xylem to living cells in stems

Cells become turgid

Turgid cells press against each other to give support to the plant

If adequate water supply,

Turgidity of cellsTurgidity of cellsInside stem of herbaceous plants

water potential of living cells

water potential of

xylem <

Cells become flaccid

Flaccid cells cannot provide support to the plantThe plant wilts

If inadequate water supply,

The hardness of thick-walled cellsThe hardness of thick-walled cellsPlants are also supported by thick-walled cells

mostly xylem cells which contain lignin

As plant grows, older xylem tissues in stems are pushed inwards and become wood.

Water absorbed by osmosis

turgid

Water lost by osmosis

flaccid

Wilting occurs

In this case, transpiration is faster than absorption of water.

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How are plants supported?

2. Support in woody stems is contributed mainly by rigidity of the lignified cells in xylem.

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How are plants supported?

Multiple choices1. Which muscles contract to effect a change fo

rm the condition shown in Diagram I to that in Diagram II?

P, Q and RP, Q and SP, R and TQ, S and T

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Multiple choices2. Which of the following functions are carried out by b

one W? (1) Producing red blood cells (2) helping in ventilation of the lung (3) protecting internal organs

(1) and (2) only(1) and (3) only(2) and (3) only(1), (2) and (3)

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Multiple choices3. Which of the joints X, Y and Z allow(s) move

ment between the bones?

Y onlyZ onlyX and Y onlyY and Z only

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Multiple choices4. Which of the following

correctly describes the functions of structures A and B?

holding the bones transmitting forcetogether to the boneacting as a pivot protecting the jointprotecting the joint preventing dislocation of

the jointtransmitting force acting as a pivotto the bone

Structure A Structure B

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Multiple choices5. The diagram below shows a man at a certain stage of swim

ming:

Which of the following combinations correctly describes the conditions of his arm muscles at this stage?

Left arm Right arm

Biceps Triceps Biceps Tricepscontracted relaxed relaxed contractedrelaxed contracted contracted relaxedcontracted relaxed contracted relaxedrelaxed contracted relaxed contracted

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Multiple choices6. The diagram below shows a human arm holding a weight:

The length of EF is shorter than the length of WF. What is the advantage of this arrangement?

The biceps would not become fatigue easily.

This would make the biceps stronger than the triceps.

Less energy would be used by the biceps in supporting the weight.

A small contraction of the biceps would move the weight through a large distance.

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Multiple choices7. Which structures are parts of the axial skeleton?

3

1, 2 and 3

1, 2 and 4

1, 3 and 4

2, 3 and 4

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Multiple choices8. Which of the following correctly lists the structures protecte

d by the different parts of the skeleton?

3

1 2 3brain aorta stomach

ears aorta heart

brain spinal cord heart

ears spinal cord stomach

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Multiple choices9. The diagram below shows a model of a movable joint:

Which of the following combinations is correct?

Type of jointrepresented by the model

Example

hinge joint knee jointhinge joint shoulder jointball and socket joint shoulder jointball and socket joint Knee joint

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Multiple choices10. The diagrams below show three sets of bones of the human skeleton:

Ball and socket joint can be formed between

1 and 3.1 and 4.2 and 3.2 and 4.

1

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Multiple choicesThe model below illustrate the movement at the elbow joint:

11. Which of the following occurs when Q is shortened?

shortened raisedshortened loweredstretched raisedstretched lowered

P S

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Multiple choicesThe model below illustrate the movement at the elbow joint:

12. The model is useful for demonstrating

the movement of the upper arm.that the joint allows 360º movement.that the biceps is stronger than the triceps.the actions of a pair of antagonistic muscles.

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Multiple choicesDiagram I shows some muscles attached to the leg bones.Diagram II shows the posture of a person sitting on a stool.

Which muscles in the person’s leg are contracted when he maintains the posture shown in the diagram II?

muscles 1 and 2 onlymuscles 1 and 3 onlymuscles 2 and 4 onlymuscles 3 and 4 only

13.

1

2

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Multiple choices14. Which of the following are involved in maintaining our postures?

(1) skeletal muscles(2) bones(3) ligaments(4) nervous system

(1) and (2) only(3) and (4) only(1), (2) and (3) only(1), (2), (3) and (4)

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Multiple choices14. Which of the following is not a function of the mammalian skeleton?

storage of fatstorage of calciumdestruction of red blood cellsproduction of white blood cells

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