MUSCLESMUSCLES

TYPES OF MUSCLETYPES OF MUSCLE

• There are There are 33 types of muscle: types of muscle:- Involuntary (smooth)- Involuntary (smooth)

– CardiacCardiac

– Voluntary (skeletal/Voluntary (skeletal/

striated/striped).striated/striped).

TYPES OF MUSCLE - TYPES OF MUSCLE - INVOLUNTARYINVOLUNTARY

• Involuntary (smooth) muscle is found Involuntary (smooth) muscle is found in the in the internal organsinternal organs of the body of the body

e.g. the stomach and e.g. the stomach and intestines.intestines.

• It is not under our ‘conscious’ control It is not under our ‘conscious’ control but works automatically but works automatically

e.g. the stomach contracts e.g. the stomach contracts automatically to digest food.automatically to digest food.

TYPES OF MUSCLE - TYPES OF MUSCLE - CARDIACCARDIAC

• Cardiac muscle is only found in the Cardiac muscle is only found in the heartheart..

• It is also It is also involuntaryinvoluntary and never and never stops working until we diestops working until we die

e.g. the heart is always e.g. the heart is always working to working to pump blood around the pump blood around the body.body.

TYPES OF MUSCLE – TYPES OF MUSCLE – VOLUNTARY/SKELETALVOLUNTARY/SKELETAL

• Voluntary muscle is associated with Voluntary muscle is associated with movementmovement, and can be found all over , and can be found all over the body attached to the skeleton.the body attached to the skeleton.

• It is under ‘conscious’ controlIt is under ‘conscious’ control

e.g. we use it when we e.g. we use it when we

choose to move.choose to move.• This is the type of muscle that you This is the type of muscle that you

will learn about in this unit.will learn about in this unit.

MAJOR MUSCLE GROUPSMAJOR MUSCLE GROUPS

ARMS AND ARMS AND SHOULDERSSHOULDERS

LEGS AND LEGS AND BOTTOMBOTTOM THORAXTHORAX

•BicepsBiceps (bends arm (bends arm at elbow)at elbow)

•TricepsTriceps (straightens arm at (straightens arm at elbow)elbow)

•DeltoidDeltoid (abducts (abducts arm)arm)

•Trapezius Trapezius (shrugs (shrugs shoulders)shoulders)

•Quadriceps Quadriceps (straightens leg at (straightens leg at knee)knee)

•HamstringHamstring (bends (bends leg at knee)leg at knee)

•Gastrocnemius Gastrocnemius (raises body onto toes)(raises body onto toes)

•GluteusGluteus Maximus Maximus (straightens leg at hip)(straightens leg at hip)

•PectoralsPectorals (brings (brings arms together in front arms together in front of body)of body)

•Abdominals Abdominals (bends upper body at (bends upper body at waist)waist)

•Latissimus DorsiLatissimus Dorsi (pulls elbows towards (pulls elbows towards back)back)

HOW MUSCLES WORKHOW MUSCLES WORK• Muscles work in pairs. When one Muscles work in pairs. When one

muscle contracts (the muscle contracts (the AGONIST AGONIST or or PRIME MOVERPRIME MOVER), the other muscle ), the other muscle relaxes (the relaxes (the ANTAGONISTANTAGONIST). This ). This creates movement of a bone at a joint.creates movement of a bone at a joint.

• The INSERTION of a muscle is where it The INSERTION of a muscle is where it attaches and attaches and resists pull.resists pull.

• The ORIGIN of a muscle is where it The ORIGIN of a muscle is where it attaches and attaches and exerts pull.exerts pull.

HOW MUSCLES WORKHOW MUSCLES WORK

• A Bicep Curl in the ArmA Bicep Curl in the Arm• The bicep would be the The bicep would be the prime prime

mover/agonist.mover/agonist. • The tricep would be the The tricep would be the antagonistantagonist..• The The originorigin of the bicep would be at of the bicep would be at

the shoulder.the shoulder.• The The insertioninsertion of the bicep would be of the bicep would be

at the elbow.at the elbow.

EXAMPLES OF EXAMPLES OF ANTAGONISTIC MUSCLESANTAGONISTIC MUSCLES

• Biceps and triceps in the upper armBiceps and triceps in the upper arm

Quadriceps and hamstring in the upper Quadriceps and hamstring in the upper legleg

TENDONSTENDONS

• Tendons attach muscle to boneTendons attach muscle to bone• TENDON OF INSERTION – exerts pullTENDON OF INSERTION – exerts pull

– In a bicep curl the tendon at the bottom In a bicep curl the tendon at the bottom of the bicep that attaches to the elbowof the bicep that attaches to the elbow

• TENDON OF ORIGIN – resists pull TENDON OF ORIGIN – resists pull – In a bicep curl the tendon at the top of In a bicep curl the tendon at the top of

the bicep that attaches to the shoulderthe bicep that attaches to the shoulder

MUSCLE FIBRE TYPESMUSCLE FIBRE TYPES

• Fast twitch fibresFast twitch fibres– Fast powerful contractionsFast powerful contractions– Enough energy for 10seconds of Enough energy for 10seconds of

exerciseexercise– Anaerobic energy systems usedAnaerobic energy systems used– E.g. weightlifting, sprinting, swimming E.g. weightlifting, sprinting, swimming

50m50m

MUSCLE FIBRE TYPEMUSCLE FIBRE TYPE

• Slow twitch fibresSlow twitch fibres– slower and less powerful contractionsslower and less powerful contractions– utilise oxygen to provide energy for utilise oxygen to provide energy for

longer longer – aerobic energy systems usedaerobic energy systems used– e.g. cross country skiing, Tour de France e.g. cross country skiing, Tour de France

(cycling), marathon.(cycling), marathon.

MUSCLE FIBRE TYPEMUSCLE FIBRE TYPE

• Everybody has Everybody has bothboth types of fibre types of fibre typetype

• It is possible to increase the It is possible to increase the efficiencyefficiency that the muscle fibres that the muscle fibres work at with trainingwork at with training

• Different activities use both fibre Different activities use both fibre types for different amounts of timetypes for different amounts of time– e.g. marathon runners use slow twitch e.g. marathon runners use slow twitch

fibres for most of the race but fast fibres for most of the race but fast twitch fibres for the sprint finishtwitch fibres for the sprint finish

MUSCLE FIBRE TYPE AND MUSCLE FIBRE TYPE AND SPORTSPORT

ACTIVITYACTIVITY SLOW SLOW TWITCHTWITCH FAST TWITCHFAST TWITCH

FOOTBALLFOOTBALL

TENNISTENNIS

BOXINGBOXING

Most of Most of gamegame

Short sprintsShort sprints

Most of matchMost of matchSprinting for the Sprinting for the

ball in a rallyball in a rally

Duration of matchDuration of match PunchingPunching

EFFECTS OF TRAININGEFFECTS OF TRAINING

• HYPERTROPHYHYPERTROPHY – – increaseincrease in in muscle size, strength and muscle size, strength and flexibilityflexibility

• ATROPHYATROPHY – – decreasedecrease in muscle in muscle size, strength and flexibility size, strength and flexibility (wasting of the muscle)(wasting of the muscle)

EFFECTS OF TRAININGEFFECTS OF TRAINING

• MARATHON RUNNERMARATHON RUNNER– slow twitch muscle fibres adapt to utilise slow twitch muscle fibres adapt to utilise

energy more efficiently and for longer periods energy more efficiently and for longer periods of timeof time

– delays the onset of muscle fatiguedelays the onset of muscle fatigue– as little muscle bulk as possibleas little muscle bulk as possible

• SPRINTERSPRINTER– more muscle fast twitch fibres are generated more muscle fast twitch fibres are generated

(muscle bulk) to give more power output(muscle bulk) to give more power output– muscles are able to maximise stored energy to muscles are able to maximise stored energy to

give greater bursts of all-out activitygive greater bursts of all-out activity