Page 195 - The Miracle of the Blood and Heart

The Heart: The Most Efficient
Machine in the World

mitted to the heart muscle by two small muscles. The cells
pass on the electrical impulse reaching them to all the other
muscle cells in the heart's lower regions. This wave of current
stimulates all the muscle cells beneath, starting with the right
atrium, and is thus disseminated throughout the heart. The
sinus node, producing and regulating these electrical currents,
is also known as the pacemaker. While controlling the rhythm,
the pacemaker also reacts to the needs of the body. It possess-
es the ability to accelerate or decelerate the heartbeat accord-
ing to the body's requirements.
The heart does not contract all at once, however, because it
has to collect blood and also to pump the blood it has collect-
ed. If all cardiac cells were to contract at once, then the blood
would be pumped before it had been properly collected; and
as a result, only a few drops of blood could be transmitted to
the body. However the blood collected by the atria must be
transmitted to the ventricles, which are larger, before the latter
contract. Therefore, the cardiac muscles wait for each other to
contract in sequence, just as if they were aware of their own
place in line. As the cardiac muscle tissue of the atrium con-
tracts, the valve separating the atrium from the ventricle
opens and allows the blood to flow downward into the ven-
tricle. Once the ventricle is full, it contracts. But how does that
sequencing manage to remain so regular?
If you examined the cardiac cells under a microscope, one
by one, you would see that each one beats at a different rate.
This is a most astonishing, but also a most miraculous state
of affairs: Far from being a sign of any irregularity, this
actually indicates an impeccable order. The heart
beats in a rhythmic and synchronized way: The cells
literally know when to contract and when to
Adnan
Oktar

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