Muscle Fibres Flashcards
Name the 3 different types of muscle fibres
Type 1 (slow oxidative)
Type 2a (fast oxidative glycolytic)
Tyoe 2b (fast glycolytic)
What sports would be have each muscle fibre in abundance
Type 1:
-marathon
-road cycling
-triathlon
Type 2a:
-games player
Type 2b:
-javelin
-100m
-high jump
What are some structural features (things you can see) of muscle fibres
-size
-colour
-mitochondria density (content)
-capillary density (content)
-glycogen store
What are some functional features (what they do) of muscle fibres
-contractile speed
-contractile force
-fatigue RESISTANCE
What colour are all 3 muscle fibres
Type 1-red (due to high blood content)
Type 2a-pink
Type 2b-white
What is the fatigue resistance of all 3 muscle fibres
Type 1-high (as they are for endurance events)
Type 2a- intermediate
Type 2b- low
What is a twitch
A single contraction
How do we control the strength on contraction
-motor unit size (larger motor unit,larger contraction)
- recruit more or less motor units (all or none law)
-increase type 2b fibres for a stronger contraction
-increase rate of stimulation
-spatial summation
What is wave summation
When a muscle fibre twitches but has less time to fully relax before the next twitch,increasing the strength of contraction
What is tetanus
When the muscle has NO time to relax so it is continuously contracting
What is spatial summation
When a motor relaxes,another motor unit will contract while it has time to recover
Once recovery has finished,the first motor unit is able to contract again
summary-allows for motor units to recover or avoid fatigue