Tanglin PE Theory - Secondary 2

1. MUSCLESMUSCLES
MUSCLES
My muscles move my body like strings move a puppet.

2. MUSCLESMUSCLES
Content Purpose
 Students will know and understand what
muscles are and how they form an important
part of our body system.

3. MUSCLESMUSCLES
Language Purpose (Topic 6.1)
 3 kinds of muscles
 Voluntary (skeletal) muscles
 Involuntary (smooth) muscles
 Cardiac muscles
 Muscle fibres
 Slow twitch muscles
 Fast twitch muscles

4. MUSCLESMUSCLES
Language Purpose (Topic 6.2)
 Names of different muscle groups
 Deltoid
 Biceps
 Abdominals
 Quadriceps
 Pectorals
 Latissimus dorsi
 Trapezius
 Triceps
 Gluteals
 Hamstrings
 Gastrocnemius

5. MUSCLESMUSCLES
Language Purpose (Topic 6.3)
 Tendons
 Insertion
 Origin
 Prime mover
 Antagonists
 Fixator
 Synergists
 Muscle tone

6. MUSCLESMUSCLES
Language Purpose (Topic 6.4 / 6.5)
 Fatigue
 Isotonic contraction
 Isometric contraction
 Flexibility

7. MUSCLESMUSCLES
Overview of Muscular
System (Video)
(click man for video)

8. MUSCLESMUSCLES
The muscular system is made up of…
muscles
and
tendons
Connects muscle
to bone

9. MUSCLESMUSCLES
Do you know…
 You have about 650
muscle groups in your
body.
 Your muscles make up
over 40% of your body
weight.
 So how much do your
muscles weigh?

10. MUSCLESMUSCLES
My muscles are important because
they…
 Hold my organs in place
 Hold my bones together so that
I can move
 Help me chew my food (Voluntary muscle)
 Open and close my eyelids (Voluntary muscle)
 Pump my blood (Cardiac muscle)
 Allow me to run and play
(Voluntary/skeletal muscle)
 Help me to smile!
(Voluntary/skeletal muscle)

11. MUSCLESMUSCLES
Did you know…
It takes more
muscles to
frown (43
muscle groups)
than to smile (17
muscle groups)?

12. MUSCLESMUSCLES
What are the different kinds
muscle?
 There are 3 different
kinds of muscles:
 Voluntary muscles
 Also known as
skeletal muscles
 The most
commonly known
kind of muscles
 Helps you to move
(eg. running and
jumping)

13. MUSCLESMUSCLES
What are the different kinds
muscle?
 There are 3 different
kinds of muscles:
 Involuntary muscles
 Also known as
smooth muscles
 Found in the
internal organs
such as
oesophagus,
stomach, intestines
 Help to push the
food through the
different systems

14. MUSCLESMUSCLES
What are the different kinds
muscle?
 There are 3 different
kinds of muscles:
 Cardiac muscles
 A special kind of
involuntary muscle
 Started to work
from the day you
are born

15. MUSCLESMUSCLES
Quick Recap:
 Voluntary muscles
 Also known as skeletal muscles
 Involuntary muscles
 Also known as smooth muscles
 Cardiac muscles
 A special kind of involuntary muscle

16. MUSCLESMUSCLES
Did you know…
 Voluntary muscles
give shape to your
body.
 Over 40% of your
weight is voluntary
muscle

17. MUSCLESMUSCLES
What are muscles made of ?
 Stretchy, elastic
cells known as
muscle fibres
 Every muscle
contains a
mixture of fibres

18. MUSCLESMUSCLES
What are muscles made of?
Slow Twitch Fibre (red)
 Contract slowly,
without much force
 Do not tire easily
Fast Twitch Fibre (white)
 Contract much faster,
with more force
 Tire quickly
Question:
What activities are fast/slow
twitch muscles suitable for?

19. MUSCLESMUSCLES
Did you know…
YOU are born with
a fixed ratio of
Slow & Fast
twitch muscle
fibres
YOU cannot
change the ratio
even with training

20. MUSCLESMUSCLES
Fast Twitch vs Slow Twitch
 Fast Twitch Fibres
 Determines how fast
you can run
 White in colour
 Training helps
making these fibres
contract more
strongly
 Training also helps in
making fibre tire a
little later
 Slow Twitch Fibres
 Determines how long
(endurance) you can
run
 Red in colour
 Training helps store
more energy so that
you can run even
longer

21. MUSCLESMUSCLES
Did you know…
Chickens have fast and slow twitch muscle, too.
Chicken wings and breasts are largely
made up of fast twitch muscle fibres.
Use their wings for brief bursts of flight.
White in colour when cooked.Chicken legs are mainly made up
of slow twitch fibres.
Use legs for walking and standing.
Reddish in colour when cooked.

22. MUSCLESMUSCLES
What are the main muscles?

23. MUSCLESMUSCLES
Functions of the main muscles
Muscle Main action(s)
1 Deltoid Raises your arm sideways at the shoulder.
2 Biceps Bends your arm at the elbow.
3 Abdominals Pull in your abdomen. Flex your trunk so you can bend forward.
4 Quadriceps Straighten your leg at the knee and keep it straight when you stand.
5 Pectorals Raises your arm at the shoulder. Draws at across your chest.
6 Latissimus
dorsi
Pulls your arm at the shoulder. Draws it behind your back.
7 Trapezius Holds and rotates your shoulders. Moves your head back and
sideways.
8 Triceps Straightens your arm at the elbow joint.
9 Gluteal Pull your leg back at the hip. Raise it sideways at the hip. Gluteus
maximus is the largest muscles.
10 Hamstrings Bend your leg at the knee.
11
Gastrocnemius
Straightens at the ankle joint so you can stand on your knees.

24. MUSCLESMUSCLES
How are muscles attached?
Tendons attach my muscles to my bone helping my
body move.
Feel your tendon right above
your heel in the back of your
leg.
This is the thickest tendon (Achilles tendon) in your
body. Fibres of the tendon are embedded in the
periosteum (fibrous membrane covering the bone) of
the bone. This anchors the tendon strongly and
spreads the force of contraction, so that it will not tear
easily.

25. MUSCLESMUSCLES
 Origin – muscle
attachment to an
immoveable bone
 Insertion – muscle
attachment to a
movable bone
 When a muscle
contracts, the
insertion moves
towards the origin
How are muscles attached?

26. MUSCLESMUSCLES
Muscle Tone
 Even when a muscle is relaxed, a small
amount of fibres are contracted
 Just sufficiently to keep the muscles tight but
not resulting in movement
 This amount of muscle contraction helps
keeping body upright when standing and
seated

27. MUSCLESMUSCLES
Did you know…
 Why you could stand straight?
Ans:
Because of good muscle tone.
Poor muscle tone –
slouching, hunch back.
Good muscle tone.

28. MUSCLESMUSCLES
 Muscles contract (shorten) to bring about
movement.
 Eg. The biceps will contract to pull the lower arm
towards the upper arm, resulting in bending of
elbow
How does muscles work?

29. MUSCLESMUSCLES
 Prime mover (Agonist) – muscle with the major
responsibility for a certain movement
 Antagonist – muscle that opposes or reverses a
prime mover
 Synergist – muscle that aids a prime mover in a
movement and helps prevent rotation
 Fixator – stabilizes the origin of a prime mover
How does muscles work?

30. MUSCLESMUSCLES
How does muscles work?
 Which is the
Agonist muscle?
Antagonist muscle?

31. MUSCLESMUSCLES
How to keep strong muscles?
 Exercise every day.
Discussion:
What are some things you can do
every day to help keep your
muscular system healthy?

32. MUSCLESMUSCLES
How does exercise affect muscles?
 Immediate effects of exercise on muscles
 Fatigue: can be mental or physical
exhaustion
 Caused by build up of lactic acid (fast twitch
muscles) that causes pain or depletion of
glycogen (slow twitch muscles)

33. MUSCLESMUSCLES
How does exercise affect muscles?
 Long-term effects on our muscles
 Muscles (voluntary muscles) grow bigger
and stronger.
 eg. Stronger cardiac muscle means more
blood can be pumped around body ( = more
oxygen)
 Long-term benefits
 Become stronger and fitter for everyday
tasks, especially important for older people
to reduce loss of strength

34. MUSCLESMUSCLES
How does training affect muscles?
 Fast Twitch Fibres - contract more strongly,
important for maximum-effort activities,
delay build-up of lactic acid
 Slow Twitch Fibres – body adapts to store
more glycogen and use fat as an energy
source
 All muscle changes are reversible.
IF YOU DO NOT USE IT YOU LOSE IT!

35. MUSCLESMUSCLES
How do you train muscles?
Two ways to train muscles
based on different kinds of
muscle contraction
Isotonic Training-when
muscles shorten and pull on
bones
Isometric Training- when
muscles contract and stay the
same length

36. MUSCLESMUSCLES
Advantages and Disadvantages of
Isotonic Training
Advantages
Strengthens muscle through
full range of movement
Can choose isotonic exercises
to suit different sports
Disadvantages
Can make muscles sore
Gain most muscle strength at
the weakest point of action

37. MUSCLESMUSCLES
Advantages and Disadvantages of
Isometric Training
Advantages
Quick to do and does not hurt.
No need for expensive
equipment, can be done
anywhere
Disadvantages
Gain most muscle strength at
the angle used in the exercise
Blood flow to muscle stops,
blood pressure rises, less blood
flows back to heart

38. MUSCLESMUSCLES
Why train muscles?

39. MUSCLESMUSCLES
Why train muscles?

40. MUSCLESMUSCLES
One way to keep my muscles strong…
 Eat foods from
the meat group
every day.
 They are high in
protein which
helps to build
strong muscles.
Name some foods that are high
in protein.

41. MUSCLESMUSCLES
Muscle Training and Flexibility
 Poor flexibility cause
poor performance
through injury (strained
or pulled muscles) or
inefficient technique.
 Hinders both speed and
endurance, muscles
need to work harder to
overcome resistance.
 Flexibility training
important for elderly.
Why?

42. MUSCLESMUSCLES
How to improve flexibility
Through
 Static stretching
 Active stretching
 Passive stretching
Do you understand each of the
above terms?
A flexible joint is less at risk of
strain. Muscles that are
stretched well can contract
more strongly.

43. MUSCLESMUSCLES
Works Cited
 My Body: Teacher Created Materials
 Encarta Encyclopedia
 Microsoft Clipart