Heart Rate Adaptation to Temperature
97
recorded by an automatic pen. In the figure the uninterrupted line shows the
response of concentration B to rectangular temperature jumps; the parameters of the model were chosen in such a manner as to simulate the results
of frog heart capacity adaptation.
In this way, the parameters of the pacemaker metabolism were summarized by the parameters of the steady state model and the biological results
examined by variation of the experimental conditions. A close analogy was
70 Heart rate
A
60
60 Heart rate
B
min
15
10
5
10
20 min
Fig. 2. Results of various experiments on the frog's heart capacity adaptation
to temperature
maintained in every variation, for example after a slow temperature rise,
with stepwise jumps or with very frequent temperature variations (Figure 2).
In the diagram of fig. 3 the dynamic (overshoot) and static (steady state)
values of heart frequency are plotted against temperature together with the
resulting value of k2 of the model system. A sigmoid plot of the temperature
response curve results; the equivalent of the model reactions were calculated with the aid of a nomogram [4]. The values of the concentration Bnow associated with the energetic source of "temperature response"-are
7 3. Symp. Quant. BiD!.