muscle skeletal system Flashcards
what are the types of contractions
isotonic, isometric, concentric, eccentric
how can muscles contract
contract and shorten or contract and legthen
what is a isotonic muscle contraction
when the muscle changes length when contracted can be split into concentric and eccentric contraction
what is a isotonic concentric contraction
when the muscle shortens when contracting
an example of isotonic concentric contraction
biceps curl
what is isotonic eccentric contraction
the muscle lengthen when contracting
an example of isotonic eccentric contraction
lowering a dumbbell
what is an isometric contraction
the muscle does not undergo any change in length when it contracts, the muscle contracts to maintain stability of the position of the body
example of a isometric contraction
a handstand
what is the name given to the agonist muscle
prime mover
what is the agonist muscle
prime instigator of a joint movement, helps to care the movement of a joints related limb
what is the antagonistic muscle
this is the muscle that opposes the motion of the agonist muscle to ensure that the movement is performed
what is a fixator muscle
the muscle works to stabilise the origin of the agonist
what is a synergist muscle
muscle that stabilises the joint that is moving
what does fle 123 mean
1st class lever system has the fulcrum in the middle
2nd class lever system has the lever in the middle
3rd class lever system has the effort in the middle
what is the load
the weight that needs to be moved
what is the effort
the force needed to move the load which is a muscle
what is the fulcrum
is the location of the movement, the joint
what is the effort arm
the distance from the fulcrum to the effort
what is the load arm
the distance from the fulcrum to the load
what are the mechanical disadvantages of the 3rd class lever system
effort is larger than load, large loads cannot be moved but smaller loads can be moved greater speeds
what is the mechanical advantages of the 2nd class lever system
load is close to fulcrum and effort is further away from the fulcrum meaning u can mover large loads
what happens in the first stage of the stretch shorten cycle
eccentric stage-allows preload of the muscle, allowing it to store elastic energy
what happen in the 2nd stage of the stretch shorten cycle
amortisation stage- between the eccentric and concentric stage, the shorter this stage the more powerful the movement
what happens in the 3rd stage of the stretch shorten cycle
concentric stage- stored elastic energy helps produce a more powerful concentric contraction
what are the different types of movement
flexion, extension
adduction, abduction
circummucation, rotation
plantar/dorsi flexion
pronation, supernantion
inversion, eversion
horizontal flexion and extension
what is pronation
rotation of forearm, so palm of hand faces outwards
what is supernantion
rotation of forearm, palm of hand faces upward
where does inversion and eversion only take place
foot/ ankle
what is inversion
turning sole of foot inwards
what is eversion
turning sole of foot outwards
what is horizontal flexion
movement of the arm in a horizontal plane towards the centre of the body
what is horizontal extension
movement of the arm in a horizontal plane away from the centre of the body
how many laws of motion is there
3
what is the 1st law called
law of inertia
what happens in the 1st law
an objects state of motion will not change unless acted upon by an external force
what is the 2nd law called
law of acceleration
what happens in the 2nd law
an object will accelerate in the same direction as the force exerted on it and the amount of acceleration is directly proportional to the force
what is the 3rd law called
law of action and reaction
what happens in the 3rd law
for every action their is a equal and opposite reaction
what is force
it is a push or pull exerted onto an object
what is the equation for force
force=acceleration x mass
what is stability
the objects resistance to a changing position
what can affect stability
area of support
centre of mass
position of the line of gravity
body mass
how will area of support affect stability
the wider the base will increase it
how will centre of mass affect stability
raising the centre of mass will reduce stability
how will the position of line of gravity affect stability
a line of gravity which is close to the centre of mass will result in greater stability
how will body mass affect stability
the greater mass of the body the greater the stability
what is centre of mass
the point at which the total body mass in concentrated
what is position line of gravity
the line through which gravity acts
characteristics of slow twitch muscle fibres
-high mitochondria density allows better energy production from aerobic system
- high myoglobin content allows better oxygen carrying capacity
-high capillary density allows better exchange of gases
-high oxidative enzyme acidity allows more energy to be produced from aerobic system.
characteristics of type 11x muscle fibres
high in pc- higher rate of contraction
high stores of pc- maintain high rate pf contraction for longer
increased fibre size-allows increased strength
high force production- allows speed/power
high actin and myosin- allows faster contraction
