Support and MovementSupport and Movement
Biology
14.2 Support in mammals
in mammals
skeletonskeletonmuscularmuscular
systemsystem
Contents
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 m
arrows?
What is the use of the bone m
arrows?
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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
Contents
Two parts of skeleton
Appendicular skeletonAppendicular skeleton• Pectoral girdles
• Pectoral limbs
• Pelvic girdles
• Pelvic limbs
Axial skeletonAxial skeleton• Skull• Sternum• Ribs• Vertebral
column
Contents
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
skeletonskeletonmuscularmuscular
systemsystem
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
Contents
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.
Contents
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 cells
Plants 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 f
orm 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
bone 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
Contents
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 contracted
relaxed contracted contracted relaxed
contracted relaxed contracted relaxed
relaxed 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 3
brain 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 joint
represented by the modelExample
hinge joint knee joint
hinge joint shoulder joint
ball and socket joint shoulder joint
ball and socket joint Knee joint
Contents
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
Contents
Multiple choicesThe model below illustrate the movement at the elbow joint:
11. Which of the following occurs when Q is shortened?
shortened raised
shortened lowered
stretched raised
stretched lowered
P S
Contents
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 only
muscles 1 and 3 only
muscles 2 and 4 only
muscles 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 fat
storage of calcium
destruction of red blood cells
production of white blood cells
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