The graph illustrates the pressure in three regions of the heart over one cycle. At $0.2\ \text{s}$, which region of the heart is reacting to the excitatory stimulus?
Biology 9700 · AS & A Level · The heart
The graph illustrates the pressure in three regions of the heart over one cycle. At $0.2\ \text{s}$, which region of the heart is reacting to the excitatory stimulus?