Figure 2: Examples of gamma distributions and associated survival functions. (a, b) The two parameters of the gamma distribution ( and ) permit description of a wide variety of distributions useful for representing the probability density function for myosin crossbridge attachment time, . Notably, a single exponential results when (a), and a Gaussian distribution is approximated as increases. (c, d) The survival function, , refers to the probability that an attached crossbridge will survive to time . The analytical relationship between the and is provided by (10a) and (10b).