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.
<span>the theory that the origin and phenomena of life are dependent on a force or principle distinct from purely chemical or physical forces.</span>. They don't believe in it anymore because it simply had to rely on to many factors that seemed unlikely.<span />
Yes. Mercury is nearly twice as heavy as tin. Explanation: The density of mercury is 13.534 g/cm3, and the density of tin is 7.31 g/cm3
