What structures within skeletal muscle tissue bring about contraction?

The correct answer identifies actin and myosin filaments as the structures within skeletal muscle tissue responsible for contraction. These two types of filaments are crucial components of the sarcomere, which is the basic contractile unit of muscle tissue.

Actin filaments are thin and provide a track for the myosin, which are thicker, to pull on during the contraction process. This interaction occurs through a series of biochemical events initiated by nervous system stimulation, which leads to the sliding filament theory. As myosin heads bind to actin and pull, the muscle fibers shorten, resulting in muscle contraction.

In contrast, the other options represent different types of connective tissues or structures that play supportive roles in the muscle system but do not directly cause contraction. The epimysium and perimysium are layers of connective tissue that envelop the muscle fibers and bundles, providing protection and structural integrity rather than participating in the contraction itself. Tendons connect muscles to bones, facilitating movement but aren't involved in the actual shortening of muscle fibers. Regular collagen fibers contribute to the structure of tendons and connective tissue but do not partake in the muscular contraction process either. Therefore, recognizing the role of actin and myosin in muscle contraction clearly defines why they are the correct