Neuromuscular System-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
-Myosin ATPase content
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 stimulation, increasing the strength of contraction
This all occurs in the SAME contraction
What is a tetanic contraction
When the muscle fibre 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
