Muscular Skeletal System Flashcards

Question

Balanced forces

Answer 1

- When forces acting on object are EQUAL but OPPOSING IN DIRECTION —-> object in constant state of motion as it’s balanced due to NET FORCE = 0

Answer 2

- When forces acting in object are unequal, object is MOVED in direction of larger force - Unbalanced forces ——> acceleration OR deceleration

Answer 3

- An object at rest tends to remain at rest - An object in motion remains in motion at CONSTANT SPEED unless an outside forces acts upon it - The inertia of an object is DIRECTLY proportional to its mass, a body w/ greater mass needs LARGER force to overcome its inertia than a a body w less mass

Answer 4

- An object will accelerate in the same direction as the force applied to it -increase in velocity of moving object is proprtional to force applied + inversly proprtial to objects mass - E.g the harder a tennis player hits a ball = greater acceleration of racket - F= M x A (N)

Answer 5

- for every action there’s a opposite and equal reaction - when 2 bodies/objects exert force on one another - Action + reaction are equal + opposite and ALWAYS occur in pairs - E.g powerlifter exerts muscular force on barbell/weight to lift it off chest during bench press + hold it above chest

Answer 6

“The objects resistance to changing position” - Area of base of support = having a wide base of support will increase stability - Center of mass= point at which total BM is concentrated (raising center of mass reduces stability)

Answer 7

- Position of line of gravity= a line of gravity closesr to center of mass will reduce stability - Body mass= greater mass of body, more stable

Answer 8

- Rate of Gas exchange increases, due to higher vol. of OXYGENATED blood to muscles = delayed onset of muscular fatigue - Increase in enzyme activity within muscles = faster + more forceful muscular contractions - Muscle viscosity reduced, improves elasticity + functional strength of muscle —-> reduced chance of injury + more efficient contractions

Answer 9

- Speed of nerve transmission increases, allowing for improved contraction speed + force production - Coordination between antagonistic pairs improved= better quality of movement - Higher vol of synovial fluid produced, increasing ROM at joint - Muscle temp increases during beginning of physical activity, improving lengthening ability of muscles/tendons = reducing risk of injury

Answer 10

- warms air - filter out dust + bacteria - moistens air so filtered

Answer 11

The structural and functional characteristics of the different fibres should then be related to the demands of the students identified sport. * Type 1 fibres are most suited to endurance based sports such as marathon running, endurance cycling or other suitable example(s) because of their ability to use oxygen and produce force for long periods of time. * Type IIx fibres are most suited to short duration, high intensity activities such as 100m sprint, long jump or other suitable examples because of their ability to exert rapid force. * Type IIa fibres are most suited to intermittent sports such as team games, tennis or other suitable examples because of their ability to use oxygen without fatigue and produce force at high rates when required.

Answer 12

- Muscle temp increases = imporoves lengthening/flexibility of muscles and reduce risk of muscle strain/tear - muscle viscocity reduced - Enzyme activity is facilitated - Muscle metabolism increased - Energy supply is made available due to brekadown of glycogen - Increased temp leads to greater elasticity of fibres - Increased elasticity of fibres causes greater speed and force of contraction - increase speed of nerve transmission = more forceful/faster contractions - More O2 is delivered to muscles = more GE in muscles tissue so muscles work longer before fatiguing - Static stretching can reduce force of contraction

Answer 13

- Horizontal flexion at shoulder created by anterior deltoid + pecs e.g tucking arms in for a tuck - Horizontal extension at shoulder created by post deltoid + lats e.g moving arms above head for prep of dive - Adduction created by lats, traps and pecs e.g fronthand strike in tennis - Abduction created by lats, traps, pecs and delts e.gbackhand serve in tennis/prep to throw discuss - Rotation e.g tennis top spin/overhead serve - Circumdruction e.g movement of arms in butterfly stroke

Answer 14

Excitation: - Nerve impulse reaches NMJ/motor end plate - Ach released synaptic cleft - Nervous stimulation of muscel tissue triggers action potential - Nerve to muscle is NMJ Contraction: - Ca2+ released + binds to troponin - Tropomyosin moves to expose active site on actin - ATP provides energy for myosin actin crossbrdiges to form - Myosin heads form - Slidint filament theory as myosin pulls on actin head - Power stroke - Recycled when ATP synthesized + relax = stimulation of nerve stops

Answer 15

- High mitochondrial density allows better energy production from aerobic resp - Slow contrcation time - High oxidative caapcity - Low glyoclytic capaicty - High myoglobin content= better 02 carrying capacity - High capillary density = better exchange of gases - Small fiber diamater allows fats diffusion/GE due to small diffusion dist - High Resistnt to fatigue + prologonged force production - Low force production

Answer 16

- nervous ss/CNS sends signals to MS - electrical impulse travles to muscle via spinal cord - nerve cell/motor neurone tranmist impulse - impulse arrives at motor end plate/NMJ - triggers release of ACH across synaptic cleft - 1 motor neurone cannot stimulate whole muscle - motor neurone stimulates motor units - reactations based on reaction time/speed of contraction - if impulse strong enough/all or nothing aw = muscle fibre is innerved/innervated/stimulated at NMJ - an action potential is reached or not according to all or none law depends in motor units contracting - wave summation

Answer 17

- wide diamater + low capillary density + few myoglobin + small mitochondria - Low oxidative capacity - High in PC (phosphocreatine) --> High rate of contraction - High stores of PC = mantain highr ate of prolonged contraction - Increase fibre size = allows increased strength of contraction - High force production= speed/power ouptut high - high levels of actin + myosin = faster contraction of muscles - High levels of ATP + glyocgen stores - Low resist to fatigue - Higehst force production - High glycolitc capacity - Fastest speed of contrcation

Answer 18

- Agonist/prime mover= responsible for movement e.g bicep brachii in flexion in bicep curl - Antagonist= prevents overstretching of agonist e.g tricep brachii in flexion during bicep curl - Fixator=stabalise bone where prime mover origantes e.g gluteus when kick ball - Synergist= stabalise joint where prime mover acting

Answer 19

- Low intensity/endurance training = recruitment of diff slow twitch MF - High intensity training e.g sprinting recruits more type 11x MF - As muscle gets stronger, fewer fibres required to provide force needed - As load increases, type IIa will be recruited to help type 1, when load even greater IIa supports IIx - High inetsnity training will increase rate of fibre recruitment/speed increases - Muscle hypetrophy + increased ATP-PC stores + adaptive energy pathways - Increase strenhth\ of contraction

Answer 20

- Exposes binding site on actin filamnets for myosin heads to attatch onto - relayed to the CNS to innitate a nervous impulse to increase tension - increased stimulation of heart muscle = increase CO - Increased speed at which nerve impulse can be tranmitted - influx of Ca2+ released = shape of troponon changes - Muscles spindles stretched duruing movement - Reduced Ph of blood during excercise - increase in muscle temp

Answer 21

- High oxidative capacity - Fast contraction time - Middle dist swimming e.g 400m - Medium resist to fatigue - High force production - High glyoclytic capacity - Medium capillary density