Final answer:
Too little overlap of filaments in a sarcomere leads to reduced tension production in muscle fibers due to fewer cross-bridges between myosin heads and actin. Optimal overlap for maximal tension is achieved at 80 to 120 percent of sarcomere resting length. Beyond these limits, tension declines significantly or is absent.
Step-by-step explanation:
When there is too little overlap of filaments, specifically in muscle cells, the ability for a muscle to generate tension is reduced. This condition relates to the structure of the sarcomere, the basic functional unit of a muscle fiber. The sarcomere's optimal tension occurs when the thickness and thinness of filaments overlap maximally, typically at 80 percent to 120 percent of its resting length. If a sarcomere is excessively stretched, beyond 120 percent, the overlap decreases and so does the ability to form cross-bridges between myosin heads and actin, resulting in a decrease in tension. Similarly, if a sarcomere is overly shortened, the overlapping reduces further as the thin filaments collide and cross into the H zone, leading to decreased tension due to less effective cross-bridge formation. In the extreme case where there is no overlap whatsoever, no tension can be produced at all.