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Table 2 A list of model variables

From: Transitioning from acute to chronic pain: a simulation study of trajectories of low back pain

The cortisol dynamics can be simulated in the HPA model by solving the coupled differential equations as proposed in Sriram et al. [47], where the variables and parameters are listed as follows:
CRH Corticotrophin-releasing hormone
ACTH Adreno-corticotrophin hormone
CORT Cortisol
GR Glucocorticoid receptor complex
Gtot Total glucocorticoid receptor
Kstress Stress or pain induced parameter
Ki Inhibition constant that regulates the strength of the negative feedback loop
Vs3, Vs4, Vs5 Rates at which the hormones CRH, ACTH and CORT are degraded enzymatically through saturation kinetics
Km1, Km2, Km3 Michaelis constant
Kd1, Kd2, Kd3, Kd5 Autonomous degradation constants
Kp2, Kp3, Kb Rates of production of ACTH,CORT and GR
n1, n2 Hill constants
K1 Activation constant