Each Muscle Fiber is Almost Filled with Thread-Like Structures Called

Question

Each muscle fiber is almost filled with thread-like structures called _______.
A) striations
B) fiber bundles
C) myofibrils
D) fascicles

Accepted Answer

Myofibrils are the thread-like structures that run longitudinally through each muscle fiber and are responsible for muscle contraction. Striations refer to the alternating light and dark bands visible in skeletal muscle fibers under a microscope. Fiber bundles are groups of muscle fibers that are surrounded by a connective tissue sheath. Fascicles are bundles of muscle fibers.