GCSE Physical GCSE Physical EducationEducation

The Muscular The Muscular SystemSystem

How does the muscular How does the muscular system produce system produce

movement?movement?

Muscle FunctionMuscle Function

The main function of skeletal muscle is The main function of skeletal muscle is to produce movement.to produce movement.

Muscles are attached to the skeleton, Muscles are attached to the skeleton, so that they can contract and pull on so that they can contract and pull on bonesbones Muscles are attached to bones by tendons.Muscles are attached to bones by tendons.

Muscles are attached at both endsMuscles are attached at both ends One end is called One end is called the originthe origin, and is fixed , and is fixed

to something rigid.to something rigid. The other end – The other end – the insertionthe insertion – is – is

attached to the bone that moves.attached to the bone that moves.

Antagonistic pairsAntagonistic pairs As muscles can only pull, not push, they are As muscles can only pull, not push, they are

usually arranged in usually arranged in antagonistic pairsantagonistic pairs One muscle will bend (flex) the joint and the One muscle will bend (flex) the joint and the

other will straighten (extend) the joint.other will straighten (extend) the joint. Whilst one muscle contracts (agonist), the Whilst one muscle contracts (agonist), the

other relaxes (antagonist). Allowing full other relaxes (antagonist). Allowing full movement at the joint.movement at the joint. E.g the bicep contracts to flex the elbow whilst E.g the bicep contracts to flex the elbow whilst

the tricep relaxes.the tricep relaxes. This is known as an This is known as an isotonic contractionisotonic contraction If both muscles contract together then no If both muscles contract together then no

movement takes place. This is known as an movement takes place. This is known as an isometric contraction.isometric contraction.

Antagonistic pairsAntagonistic pairs

PectoralsDeltoids

Biceps

Abdominals

Quadriceps Hamstrings

Latissimus Dorsi

Trapezius

Triceps

Gastrocnemius

Gluteals

Front View Back View

The Muscular SystemThe Muscular SystemThese are the major muscles of the body…These are the major muscles of the body…

MusclesMuscles

There are 3 types of muscles There are 3 types of muscles within the muscular system:within the muscular system:Voluntary (skeletal)Voluntary (skeletal)InvoluntaryInvoluntaryCardiacCardiac

Voluntary (skeletal) Voluntary (skeletal) musclemuscle

Are under the control of our Are under the control of our willwill

Attached to the skeletonAttached to the skeleton Made up of cylindrical Made up of cylindrical

fibresfibres Usually long and thin and Usually long and thin and

found in pairsfound in pairs The cannot push.The cannot push.

Involuntary musclesInvoluntary muscles

Found in the organs of our bodyFound in the organs of our body Digestive, circulatory and urinary Digestive, circulatory and urinary

systemssystems Controlled by the involuntary Controlled by the involuntary

nervous systemnervous system Made of spindle shaped fibresMade of spindle shaped fibres

Cardiac MuscleCardiac Muscle Found in the wall of the Found in the wall of the

heartheart InvoluntaryInvoluntary Made up of interlaced Made up of interlaced

fibres, which help the fibres, which help the nervous impulses, sent nervous impulses, sent by the brain to regulate by the brain to regulate our pulse and the force our pulse and the force of our heart beat.of our heart beat.

It never tires (as long as It never tires (as long as it has a good blood it has a good blood supply).supply).

Functions of the Body MusclesFunctions of the Body Muscles

MuscleMuscle Position in the Position in the bodybody

Main ActionMain Action

Gluteals In the middle of the In the middle of the body at the back, body at the back, forming the forming the bottom.bottom.

At the top of each At the top of each leg at the back.leg at the back.

At the bottom of At the bottom of each leg at the each leg at the back. Also known as back. Also known as the calf muscles.the calf muscles.

Pull or extends Pull or extends the legs back at the legs back at the hips.the hips.

Bend or flexes Bend or flexes the legs at the the legs at the knees.knees.

Straighten the Straighten the foot so you can foot so you can stand on your stand on your toes.toes.

Hamstrings

Gastrocnemius

MuscleMuscle Position in the Position in the BodyBody

Main ActionMain Action

Latissimus

Dorsi

Triceps

At the back of At the back of the body, either the body, either side of the chest.side of the chest.

At the top of At the top of each arm at the each arm at the back.back.

Extension and Extension and adduction of the adduction of the shoulders and shoulders and back behind back behind your back.your back.

extension the extension the arms at the arms at the elbow.elbow.

Trapezius

In the centre of In the centre of the chest at the the chest at the back of the body, back of the body, spreading up.spreading up.

Hold and rotate Hold and rotate the shoulders the shoulders and also move and also move the head back the head back and sideways.and sideways.

MuscleMuscle Position in Position in the Bodythe Body

Main ActionMain Action

Deltoids

Biceps

Quadriceps

In the upper In the upper part of the part of the body, covering body, covering the shoulders.the shoulders.

At the top of At the top of each arm at each arm at the front.the front.

At the top of At the top of each leg at each leg at the front.the front.

Raise the arms Raise the arms in all directions in all directions at the at the shoulders. shoulders. AbductionAbduction

Flex the arms Flex the arms at the elbows.at the elbows.

Extension the Extension the legs at the legs at the knees.knees.

MuscleMuscle Position in the Position in the bodybody

Main ActionMain Action

Pectorals In the upper In the upper part of the part of the chest at the chest at the front.front.

At the front of At the front of the body in the the body in the middle, just middle, just below the chest.below the chest.

Raise the arms Raise the arms up, sideways and up, sideways and across the chest across the chest at the shoulders.at the shoulders.

Pull in the Pull in the abdomen and abdomen and flex the spine so flex the spine so you can bend you can bend forward.forward.

Abdominals

Structure of muscleStructure of muscle Muscles are made Muscles are made

up of many muscle up of many muscle fibres, each of fibres, each of which contain which contain many myofibrils.many myofibrils.

These can either These can either be slow twitch or be slow twitch or slow twitch.slow twitch.

Types of Muscle FibreTypes of Muscle Fibre

Slow twitch (Oxidative) FibresSlow twitch (Oxidative) Fibres Deep red in colourDeep red in colour Have a good Oxygen supplyHave a good Oxygen supply They contract slowly, but can work for They contract slowly, but can work for

long periods of time without tiring.long periods of time without tiring. Fast twitch (Glycolytic) FibresFast twitch (Glycolytic) Fibres

White in colourWhite in colour A more forceful contraction, but fatigue A more forceful contraction, but fatigue

relatively quickly.relatively quickly.

Muscle ToneMuscle Tone Muscle cells are never all resting at the same Muscle cells are never all resting at the same

time.time. Some are muscles are always ready for action – Some are muscles are always ready for action –

this is known as this is known as muscle tone.muscle tone. One of the functions of muscle tone is that it One of the functions of muscle tone is that it

keeps the body primed and ready for instant keeps the body primed and ready for instant action.action. Also keeps the body in an upright positionAlso keeps the body in an upright position

This is called This is called POSTUREPOSTURE

Our joints are held firm by the flexor and Our joints are held firm by the flexor and extensor muscles both working at the same timeextensor muscles both working at the same time

Exercise & the Muscular Exercise & the Muscular systemsystem

What are the immediate effects of What are the immediate effects of exercise on the muscular system?exercise on the muscular system? Exercise increases the body’s demand for Exercise increases the body’s demand for

Oxygen and glycogen as the muscles need Oxygen and glycogen as the muscles need more fuel to function.more fuel to function.

Extra waste products are created, and extra Extra waste products are created, and extra blood needs to be pumped around the body to blood needs to be pumped around the body to take these away.take these away.

Aerobic exercise can continue for a sustained Aerobic exercise can continue for a sustained period of time as the intensity is relatively period of time as the intensity is relatively low.low.

High intensity exercise will result in the High intensity exercise will result in the production of lactic acid, if this builds up production of lactic acid, if this builds up then exercise will cease as muscles begin to then exercise will cease as muscles begin to ache and possibly cramp.ache and possibly cramp.

What are the long term What are the long term effects of exercise?effects of exercise?

Increased muscle size: HypertrophyIncreased muscle size: Hypertrophy

Training using the principle of progressive Training using the principle of progressive overload, applies stress to the skeletal overload, applies stress to the skeletal muscles.muscles.

This results in them being damaged as the This results in them being damaged as the muscle fibres are pulled apart causing muscle fibres are pulled apart causing trauma.trauma.

The body rebuilds bridges between muscle The body rebuilds bridges between muscle fibres, and actually makes them slightly fibres, and actually makes them slightly strongerstronger This requires up to 48 hours.This requires up to 48 hours.

Potential injuriesPotential injuries AtrophyAtrophy

Loss of muscle mass & strength due to Loss of muscle mass & strength due to stopping training.stopping training.

Soft tissue injuriesSoft tissue injuries Include tears, pulls & strainsInclude tears, pulls & strains Small muscle fibres may be torn from their Small muscle fibres may be torn from their

attachment to a tendonattachment to a tendon During intense During intense

competition muscle fibres competition muscle fibres contract & relax very contract & relax very quickly, & this can cause quickly, & this can cause connective tissue & the connective tissue & the blood vessels which run blood vessels which run inside them to be torn.inside them to be torn.

TaskTask

Why do we warm up & cool down?Why do we warm up & cool down? What should be included in a warm What should be included in a warm

up?up? Design an appropriate warm up for Design an appropriate warm up for

one of your chosen sports.one of your chosen sports.