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