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.
I think its strain or sprained
True, there are many vessels serving as a conduit<span> between the lungs and the heart.
The number of the vessel is many because all the carbon dioxide from body need to be released at the lungs. More vessel means more surface area and blood flow rate to do the diffusion of the gas which means increased diffusion rate. This will allow the lung to transfer oxygen and dump carbon dioxide faster.</span>
<span>The best place to test the pulse is just below the base of the thumb, on the wrist. This allows the person to continue their exercise while still being able to check the pulse rate and see if it has reached the level they are desiring.</span>
