PHYSIOLOGY
DIFFERENT TYPE AND STRUCTURE OF MUSCLE FIBERS
|
Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
|
|
|
True
|
|
|
False
|
|
|
Either A or B
|
|
|
None of the above
|
Detailed explanation-1: -Human muscle fibers are generally classified by myosin heavy chain (MHC) isoforms characterized by slow to fast contractile speeds. Type I, or slow-twitch fibers, are seen in high abundance in elite endurance athletes, such as long-distance runners and cyclists.
Detailed explanation-2: -Type 1 (“slow twitch”) fibers contain more mitochondria, which means they can produce more energy and are better for long, aerobic activities. Type 2 (“fast twitch”) fibers, on the other hand, are suited for short, fast bursts of activity that don’t require as much oxygen.
Detailed explanation-3: -Type I fibers have low ATPase activity (at pH 9.4), are slow twitch, have high oxidative and low glycolytic capacity, and are relatively resistant to fatigue.