The main responsible for the delay among the atrial and
ventricular contractions is the action potential conduction velocity of the AV
node cells. If the atria and ventricles contract simultaneously, atria cannot
give any help in filling the ventricles, which is needed, especially in those
with stiff ventricles as in the elderly. Hence atria have to contract first and
then the ventricles.
Answer:
explanation below
Explanation:
The control group would be the biodiversity of the trees without the fire
The control group in the experiment would center on the biodiversity of the trees without the fire. Ideally, both the control group and the experimental groups are usually identical in every way except that the experimental group would receive the treatment that is believed to have an effect on the biodiversity of trees.
Pressure would be my best guess, since no choices were given.