GCSE Physical GCSE Physical EducationEducation
The Muscular SystemThe Muscular System
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…
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
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) InvoluntaryInvoluntaryCardiac Cardiac
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.
EFFECTS OF EXERCISE EFFECTS OF EXERCISE TASK…TASK…
WHAT ARE THE EFFECTS OF WHAT ARE THE EFFECTS OF EXERCISE?EXERCISE?
INCLUDE:INCLUDE: FIBRES LENGTHEN AND SHORTENFIBRES LENGTHEN AND SHORTEN EXTRA WASTE PRODUCTS CREATEDEXTRA WASTE PRODUCTS CREATED EXTRA BLOODEXTRA BLOOD ANAEROBIC AND AEROBICANAEROBIC AND AEROBIC LACTIC ACIDLACTIC ACID CRAMPCRAMP
HOW DO MUSCLES WORK?HOW DO MUSCLES WORK? DRAW UP A TABLE TO GIVE AND DRAW UP A TABLE TO GIVE AND
EXPAIN EXAMPLES OF EACHEXPAIN EXAMPLES OF EACH
1. Isotonic Contraction
Force
The muscle changes length as it works; either lengthening or shortening.
Shortening is called a concentric contraction. Give examples Lengthening is called an eccentric contraction. (Acts as a break) The hamstrings and quadriceps in the legs work in this way when performing squats.
The 'biceps curl' is a good example of isotonic contraction.
Lengthening
Eccentric Contraction
Shortening
Concentric contraction
2. Isometric Contraction
The hand push is another good example of isometric contraction. NAME SPORTS THAT REQUIRE ISOMETRIC CONTRACTION
ForceForce
There is no movement!
As a result there is no movement.
The muscle stays the same length as it works.
The muscles in the back are a good example - the trapezius works in this way when maintaining our posture.
.
Antagonistic pairsAntagonistic pairs
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
HomeworkHomework
EXPAIN IN DETAIL WHAT IS EXPAIN IN DETAIL WHAT IS MEANT BY:MEANT BY:
HYPERTROPHYHYPERTROPHY ATROPHYATROPHY