Muscular system

muscular system - response single exercise

Increased blood supply- Meets demand for O2 and glucose. Vasodilation. Removes CO2

Increased muscle temperature - fuel broken down for energy release creates heat as by product.

Increased muscle pliability- muscle warming = more piable / flexible muscles. Helps to reduce injury

Lactate build up - high intensity exercise = lactic acid by product. if not removed fatigue set in quickly

Micro tears - resistance training causes micro tears. eccentric contractions. protein helps repair

DOMS (delayed onset of muscle soreness) - pain 24-48 hrs after exercise, lasts upto 3 days, caused by micro tears

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muscular system - long term adaptations

Hypertrophy - resistance training causes overload, muscle fibres grow, contract with greater force.

Increased tendon strength - fibrous connective tissue, increase in strength + flexibility via exercise.

Increased number + size mitochondria - increase in fibre size = more room = mitochondria increase in number, therefore more aerobic energy can be produced.

Increased myoglobin stores - binds and stores O2 in muscle cells, passes O2 to mitochondria = greater aerobic energy produced.

Increased glycogen storage - muscles store more glycogen, used as fuel, increased high intensity exercise duration.

Increased storage of fat - used as a fuel when O2 present, used when carbs are running out.

Increased tolerance to lactate - more efficient clear LA away quicker + get O2 to muscles greater number of capillaries help, delays fatigue

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Muscle tissue type

Smooth muscle

  • walls of Stomach / intestines / blood vessels 
  • involuntary

Cardiac muscle

  • myocardium / walls of the heart 
  • Non-fatiguing
  • involuntary (contractions)
  • only in the heart 

Skeletal muscle

  • voluntary
  • fatiguing
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Cramp + Age

Cramp is:

  • involuntary sustained skeletal muscular contraction / spasm
  • prevents muscle movement
  • occurs due to dehydration / lack of electrolytes / salt
  • prevents performer from: running/kicking ball/throwing etc...

Age affects:

50 yrs old muscle mass starts to reduce, sarcopenia. Reduces muscle strength + power.

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  • Myoglobin carries oxygen
  • therefore muscles increase their oxidative capacity
  • muscles can work at higher intensity / longer duration 
  • fatigue delayed / occur later in the game / be able to play until the end.
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Muscle contractions (Press up)

Upward Phase

  • Pectoralis major (shoulder) agonist / Tricep (elbow) agonist / concentrically contract
  • Trapezius/rhomboids + bicep antagonists / contract eccentrically
  • Synergists support agonist / Deltoids synergists / concentrically contract
  • Fixators prevent unwanted movement / Abdominals, obliques, quadriceps / fixator muscles contract isometrically

Downward Phase

  • Pectoralis major (shoulder) agonist / Tricep (elbow) agonist / eccentrically contract
  • Trapezius/rhomboids + bicep antagonists / contract concentrically
  • Deltoids synergists and contract eccentrically
  • Abdominals, obliques and quadriceps fixator muscles / contract isometrically
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Muscle contraction types

Agonist - contracts concentrically, AKA prime mover, initiates the movement

Antagonist - relaxes during movement, opposite muscle to agonist, eccentric contraction

Synergist - support to agonist, additional smaller smaller muscles, eccentric/concentric contraction

Fixator - contract isometrically, stabilising the (origin) of agonist/muscle, supports agonist to carry out movement, stops unwanted movement, stops weight from crashing down causing injury

Concentric - Increase of tension in the muscle + shortens in length (e.g. bicep curl - bicep - upward phase)

Eccentric - increase in tension + lengthening of muscle / breaking action (e.g. press up - tricep down phase)

Isometric - contraction no movement takes place + remains same length under tension (e.g. bicep curl - bicep when holding the weight with a bent elbow)

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  • Muscles increase pliability due increased temperature
  • muscle greater ability to stretch
  • reduce risk of injury
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Muscle Fibre Types

Type 1

  • utilise the aerobic energy system
  • resistant to fatigue
  • continuous contraction meets demands of longer events 

Type IIa

  • fast contracting/they can produce great force
  • work at a high intensity
  • keep exercising fast / maintain + finish quicker

Type IIx

  • Fast twitch glycolytic contract producing high force
  • football for speed / power based movements e.g a shot / jumping for a header 
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