1. 1.1 – The structure and functions of the muscular system
Learning objectives
To understand the three muscle types and their functions
To be able to label the voluntary muscles in our body
To explain the term ‘antagonist pair’ and provide examples
To understand the characteristics of fast and slow twitch muscle fibres

2. Connective tissues There are 3 types of connective tissue:
Tendons connect muscles to bones.
Ligaments are tough, elastic fibres that link bones to bones.
Cartilage prevents the ends of bones rubbing together at joints.
Photo by: © deshow.net

3. Joint Movements 1. Flexion and Extension
FLEXION – Decreasing the angle at a joint. (Bending the joint)
EXTENSION - Increasing the angle at a joint. (Straightening the joint)
Photo: © LOCOG
Photo: © toga on Flickr. This image is reproduced under the terms of the Creative Commons License 3.0.

4. Joint Movements 2. Abduction and Adduction
Abduction and Adduction is determined from the ‘MIDLINE’ of the body.

5. Joint Movements ADDUCTION –
Sideways moving limb towards midline of the body.
ABDUCTION –
Sideways moving limb away from midline of the body
REMEMBER: Adduction is to ADD towards the midline.
REMEMBER: Abduction is to TAKE AWAY from the midline.
Photo: © LOCOG

6. Joint Movements 3. Rotation/Circumduction
The joint moves in a circular motion. e.g. Service action or bowling action.
Photo: © LOCOG
Photo: © ervine_wa on Flickr. This image is reproduced under the terms of the Creative Commons License

7. Joint Movements 4. Planter-Flexion and Dorsi-Flexion Planter-flexion –
The action of pointing toes away from the body.
Dorsi-flexion –
The action of pulling toes towards the body.
Photo: © LOCOG
Photo: © ervine_wa on Flickr. This image is reproduced under the terms of the Creative Commons License

8. Apply it! What has stuck with you?
What movements occur during these action?
Photo: ©LOCOG

9. Cyclist Footballer Swimmer - Start Butterfly Stroke
FLEXION – at the RIGHT knee joint
EXTENSION - at the LEFT knee joint
FLEXION – at the RIGHT hip joint as the leg raises
FLEXION – Slight Flexion at the elbows
FLEXION – Torso (body is bent forwards)
EXTENSION – at the knee joints
FLEXION – at the HIP JOINT of right leg
ADDUCTION – at the hip joint as the left leg is moving towards the central line of the body
ADDUCTION – Left arm
FLEXION – at left elbow
Swimmer - Start
Butterfly Stroke
ADDUCTION – of the arms
EXTENSION – at the knee joints
EXTENSION – at the elbows
ROTATION – at the shoulder joint
EXTENSION – at elbow joints
ABDUCTION – of the arms

10. Label as many joint movements as you can see.
i.e. flexion at the knee
Photo: © LOCOG
Photo: © Ronnie Macdonald on Flickr. This image is reproduced under the terms of the Creative Commons License

11. Classification and Characteristics of Muscles
Muscles are used in everyday life all the time. Sportspeople are reliant on the power of muscles to compete.
Photo by: © paddynapper on Flickr. This image is reproduced under the terms of the Creative Commons License 2.0.
Photo by: © deshow.net
What do you know about muscles already?

12. Classification and Characteristics of Muscles
Muscles are involved in every movement in your body.
Muscle is a special type of tissue made up of fibres that contract (shorten) and relax (lengthen).
There are three types of muscle fibre.
Photo: © Stock.xchng.

13. Classification and Characteristics of Muscles
1. Voluntary Muscles
These are attached to bones and they work whenever we want them to. e.g. Biceps & Triceps. These muscles are under
our conscious control.
Photo by: © LOCOG

14. Classification and Characteristics of Muscles
2. Involuntary muscle
These are found on the walls of the internal organs and they contract in waves.
Food travels through the digestive system and blood through the blood vessels in this way.
Photo: © Stock.xchng.
It works without you consciously controlling it, or even being aware of it.

15. Classification and Characteristics of Muscles
3. Cardiac muscle
This is a special type of muscle that forms the walls of the heart chambers.
It is a type of involuntary muscle, as it contracts without conscious thought or effort.
Photo: © istock Photo
It works non-stop without ever tiring. When it contracts it pumps blood out of the heart and around the body.

16. Classification and Characteristics of Muscles
All three types of muscle are important in physical activity:
Voluntary muscles enable movement throughout the body.
Involuntary muscles are essential in maintaining healthy body systems.
Cardiac muscle is vital in sport because it makes the heart pump. Fitness training will strengthen cardiac muscle making the heart more efficient at pumping blood around the body.

17. Voluntary Muscles Triceps Pectorals Deltoid Bicep Latissimus Dorsi
External Obliques
Abdominals
Gluteus Maximus
Hip Flexors
Hamstring
Quadriceps
Photo: © Stock.xchng.
Gastrocnemius
Tibialis Anterior

18. Muscles shorten when they contract and lengthen when they relax.
Voluntary Muscles
What happens when muscles contract?
Muscles shorten when they contract and lengthen when they relax.
Photo: © Stock.xchng.
Photo (Fencing): © LOCOG

19. Voluntary Muscles
When you contract your QUADRICEP what is the effect on the limb?
When you contract your HAMSTRING what is the effect on the limb?
When you contract your DELTOID what is the effect on the limb?
Photo: © Stock.xchng.

20. Now complete the grid below. What happens when each muscle contracts?
Main Action (s) 1
Deltoid 2
Biceps 3
Abdominals 4
Quadriceps 5
Pectorals 6
Latissimus Dorsi 7
External Obiliques 8
Triceps 9
Gulteus Maximus 10
Hamstring 11
Taibialis Anterior 12
Gastrocnemius 13
Hip Flexors

21. Muscle Main Action (s) Deltoid Biceps Abdominals Quadriceps Pectorals1
Deltoid 2
Biceps 3
Abdominals 4
Quadriceps 5
Pectorals 6
Latissimus Dorsi 7
External Obiliques 8
Triceps 9
Gulteus Maximus 10
Hamstring 11
Taibialis Anterior 12
Gastrocnemius 13
Hip Flexors
Raises arm sideways at the shoulder (abduction)
Bends arm at the elbow (Flexion)
Flexes trunk so you can bend forward
Straighten leg at the knee (extension)
Draws arm across chest
Pulls arms backwards towards back
Allows twisting and turning of the torso
Straightens arm at the elbow joint (extension)
Pull leg back at hip.
Bends leg at the knee. (flexion)
Answers
Flexes the ankle joint so you can pull toes towards the body
Extends the ankle joint so you can stand on tiptoes
Pulls upper leg towards the chest

22. Antagonistic muscle action
The fixed or non-moving end is known as the origin.
The insertion is known as the moving end.
Photo: © Stock.xchng.
Muscles are arranged in antagonistic pairs.
As one muscle contracts (shortens) its partner relaxes (lengthens). E.g. Bicep and Tricep.

23. Antagonistic muscle action
Can you think of another antagonists pair in the body?
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24. Antagonistic muscle action
Gastrocnemius and Tibialis Anterior acting at the ankle joint
Hamstring and Quadricep acting at the knee joint.
Hip Flexors and Gluteus Maximus acting at the hip joint.
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25. Muscle fibre types
Muscle twitch fibres occur in different proportions in different people.
This proportion is mainly to do with the genes you inherit but can be altered by training.
Photo by: © deshow.net
Photo by: © LOCOG

26. Muscle fibre types What do you know about muscle fibres already?
Photo by: © LOCOG
What do you know about muscle fibres already?

27. Muscle fibre types There are two main types of muscle fibres:
1. SLOW TWITCH MUSCLE FIBRES – Small in size. These fibres take a relatively long time to contract.
Photo by: © Ronnie Macdonald on Flickr. This image is reproduced under the terms of the Creative Commons License
Have a good oxygen supply and is why they are deep red in colour.
They contract slowly, but can work for long periods.

28. Muscle fibre types
2. FAST TWITCH MUSCLE FIBRES - Large in size. These fibres contract quickly and powerfully.
Photo by: © bleublogger on Flickr. This image is reproduced under the terms of the Creative Commons License 2.0.
Fast twitch fibres are paler in colour and have limited oxygen supply.
They contract quickly and powerfully, but tire easily.

29. 60% Slow twitch 40% Fast twitch fibres Muscle fibre types
An average person possesses:
60%
Slow twitch
40%
Fast twitch fibres
Elite endurance athletes possess a high percentage of slow twitch fibres.
Elite explosive athletes possess a high percentage of fast twitch muscle fibres.
Photo by: © rich115 on Flickr. This image is reproduced under the terms of the Creative Commons License

30. Apply it! Musculo-skeletal system What has stuck with you?
What are the 3 classification of muscle types?
Explain what is meant by an antagonistic pair and an example in the body?
Highlight and name as many muscle as you can!
Explain the difference between fast and slow twitch muscle fibres.
Musculo-skeletal system

31. Apply it! What has stuck with you?
Will each of the athletes below require mostly fast twitch or slow twitch muscle fibres and why?
Photo by:
Photo by: © deshow.net
© LOCOG

32. Practice it! Exam questions
1. Figure 4 shows a high board diver in flight.
Complete the following statements about the diver.
(i) The high diver has his legs at the knee and folded his body by at the
joint to allow him to bend forward (3)
(ii) The diver’s arms are at the elbow. The muscle that contracts to bring about this movement is the (2)

33. Practice it! Exam question
2. Using examples to illustrate your answer, describe the differences between slow and fast twitch muscle fibres. (4)
3. What percentage of fast twitch and slow twitch muscle fibres would a midfield football player need and why? (3)

34. Practice it! Marks Scheme:
i) Extended/extension, Flexing/flexion, Hip ii) Flexed, Bicep
Endurance event – slow twitch fibres (Marathon runner) Better oxygen content/delivery therefore allows athletes to continue to work without tiring. Power event – fast twitch fibres (100m Sprinter) Not as dense oxygen supply but powerful contraction possible.
70%/30% - slow/fast twitch fibres. Position requires endurance to cover all areas of the pitch both attack and defence. Powerful sprints required at times to make runs and track attacking players.