Muscle Fibres

Question 1

Name the 3 different types of muscle fibres

Answer 1

Type 1 (slow oxidative)
Type 2a (fast oxidative glycolytic)
Tyoe 2b (fast glycolytic)

Question 2

What sports would be have each muscle fibre in abundance

Answer 2

Type 1:
-marathon
-road cycling
-triathlon

Type 2a:
-games player

Type 2b:
-javelin
-100m
-high jump

Question 3

What are some structural features (things you can see) of muscle fibres

Answer 3

-size
-colour
-mitochondria density (content)
-capillary density (content)
-glycogen store
-Myosin ATPase content

Question 4

What are some functional features (what they do) of muscle fibres

Answer 4

-contractile speed
-contractile force
-fatigue RESISTANCE

Question 5

What colour are all 3 muscle fibres

Answer 5

Type 1-red (due to high blood content)
Type 2a-pink
Type 2b-white

Question 6

What is the fatigue resistance of all 3 muscle fibres

Answer 6

Type 1-high (as they are for endurance events)
Type 2a- intermediate
Type 2b- low

Question 7

What is a twitch

Answer 7

A single contraction

Question 8

How do we control the strength on contraction

Answer 8

-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

Question 9

What is wave summation

Answer 9

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

Question 10

What is tetanus

Answer 10

When the muscle has NO time to relax so it is continuously contracting

Question 11

What is spatial summation

Answer 11

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