Sliding filament theory

Muscle contraction:

when muscle contracts the sarcomere becomes smaller, but the filaments do not change length but rather they slide past each other and overlap. The actin filaments slide between the myosin filaments so the zone of overlap becomes larger.

• I bands shrink
• z lines get pulled closer together due to the movement of actin filaments
• the filaments become interlocked
• heads of myosin filaments cross-bridges with actin…