In human skeletal muscles,the muscle fiber type with the fastest shortening velocity is the _______ fiber.
A)type I
B)type IIa
C)type IIx
D)type IIb

Question

Quizplus · Accepted Answer

Type IIx fibers have the largest diameter and the least amount of mitochondria, but they contain the highest amount of myosin ATPase and glycolytic enzymes. This results in a faster contraction time and higher force output compared to Type I and Type IIa fibers. However, Type IIx fibers are highly fatigable and are usually recruited only during high-intensity, short duration activities.

In Human Skeletal Muscles,the Muscle Fiber Type with the Fastest