Immediately after a muscle fiber is stimulated by a nerve — when calcium ions are flooding into the sarcomeres to pull away those two protein bodyguards of tropomyosin and troponin from the actin — that's called the latent period.

肉纤维被神经刺激后立即——钙离，将动蛋白中保护原球蛋白和钙蛋白的蛋白质带走——这称为潜伏期。