1. THE MUSCULAR SYSTEM

2. Learning goals By the end of this unit you should be able to
identify and describe the composition of skeletal muscle
identify and describe different muscle fibre types
indentify the major muscle groups
describe the roles of muscles in movement including the role of antagonistic pairs, prime movers and synergists
describe the role and function of tendons
identify how improved muscle functioning can improve performance and participation in physical activities

3. Types of muscle Approximately 45% of or body weight is muscle
There are 3 types of muscle tissue
1. voluntary / skeletal muscle which are attached to the skeleton and which we control.
2. involuntary muscle which are not under our control and contract / relax automatically
3. cardiac muscle found in the wall of the heart that will never tire as long as it has a good blood supply

4. SKELETAL MUSCLE Muscle is made of protein
Skeletal muscle is made up of cylindrical fibres
Skeletal muscle cells are long and thin
All these muscles are attached to the skeleton
These muscles pull on bones to create movement

5. Skeletal muscle Muscles are made of many fibres
Each fibre contains many myofibrils

6. TRAPEZIUS
DELTOID
PECTORALS
TRICEPS
BICEPS
LATISSIMUS DORSI
ABDOMINALS
GLUTEALS
QUADRICEPS
HAMSTRINGS
GASTROCNEMIUS

7. Function of different muscle groups upper body and limbs
holds back the shoulders
is attached to head and neck
Functions are to lift shoulders, to brace back and rotate scapula
Adduction and rotation of arms
Adduction of the arms and draws arms forwards and rotates it
TRAPEZIUS LATISSIMUS DORSI PECTORALS

8. Function of different muscle groups upper body and limbs
DELTOID ABDOMINALS BICEPS AND TRICEPS
Abduction of the arm and lifts arm above the head
Holds your stomach in as well as flexion and rotation of trunk
Flex and extend arm

9. Function of different muscle groups lower body
GLUTEUS MAXIMUS QUADRICEPS HAMSTRINGS GASTROCNEMIUS
Pulls leg backwards
Extends the leg
Flexes the leg backwards
Ends in the Achilles tendon and points toes away

10. MUSCLES AND MOVEMENT The skeleton provides attachment for the muscles
Muscles contract against the skeleton to move
Most muscles are long and thin, when they contract they get shorter and thicker

11. Muscle and movement Muscles are attached to the bones by tendons.
Muscles are attached at both ends. At the origin to something rigid and at the insertion which is the bone it moves.
Muscles work in pairs. One muscle contracts whilst the other relaxes. This is called antagonistic action.

12. Muscle and movement
A prime mover is the main muscle that moves the joint in a particular direction.
A synergist will work with another muscle to create movement. Often it works in stabilising a joint for movement to occur.

13. QUESTIONS For the following actions work out Antagonistic pair
Contracting muscle
Relaxing muscle
Fixator point
Insertion point
Flexion of arm at elbow
Flexion of leg at knee

14. QUESTIONS
For the muscles mentioned give an example how they are used specifically in a sport.

15. DIFFERENT MUSCLE FIBRES AND SPORT
There are two types of muscle fibres
i) fast twitch fibres
ii) slow twitch fibres
Fast twitch fibres are used for short bursts of energy usually in explosive activities. They only have a limited oxygen supply so tire quickly. Best used for speed events, throwing and jumping
Slow twitch fibres are used for slow prolonged activities involving endurance. They can contract many times and stay efficient for long periods. They have a good oxygen supply. Best suited to long distance running, cycling, swimming.

16. For the following decide what type of muscle fibre is being used
ACTIVITY
MUSCLE FIBRE
100m sprint
300m race
Throwing a javelin
Kicking a penalty in rugby
10k Cycle race
A handspring vault in gymnastics
1500m swim

17. Training the muscular system
STRENGTH – the maximum force a muscle can contract. By repeating strength exercises the size of the muscle increases as well as becoming stronger. Increased muscle size is advantageous in several sports. Weight training can be used to increase strength and the athlete would lift heavy weights for a few repetitions.

18. Training the muscular system
MUSCULAR ENDURANCE – means that the muscle can continue to work over a long period of time without tiring. Training the muscles this way will not increase muscle size only their ability to work for longer. If weight training is used then light weights with lots of repetitions would improve muscle endurance. Muscular endurance is needed in specific sports like long distance running but also in general in games.

19. Training the muscular system
List 5 sports which you specifically need muscular strength for and explain why
List 5 sports you specifically need muscular endurance for and explain why.

20. Muscular contractions
ISOTONIC MUSCULAR CONTRACTIONS – this is when there is movement of the body. The muscle will contract and relax – shortening and lengthening as it does. Working the muscles isotinically improves dynamic strength.

21. Muscular contractions
ISOMETRIC MUSCULAR CONTRACTIONS - this is when the muscle length stays the same. Used for stabilising parts of the body and holding the body steady so movement can take place. Working the muscles isometrically improves static strength.

22. Muscular contractions
ISOMETRIC CONTRACTION
ISOTONIC CONTRACTION
Fill in the table with specific examples from sport