- Heart
The Heart is the center of our circulatory system. It is the source of the force that drives circulation, the biologic pump of our life's blood and the key structure that stands between the two different currents - pulmonary and systemic, that underlie both oxygenation and acid-base balance of the body's tissues. Those are novel words to decribe the heart, but the description is an accurate one. Let's look at how the movement and the physical form of the human heart are, together, vital for health. That picture is one that allows a clear understanding of how such problems as arrythmias after "heart attack" and the kinds of congenital abnormalities that cause "blue babies" occur.
Beating from long before our birth until - by some definitions - the moment of our death, it is the heart that propogates the pulse of life. The heart is a structure, too, that stands as the great wall between two separate circulations, that of the lungs and that of the rest of the body. This division means everything as far as allowing oxygen to reach our cells in the quantities that they thrive on, and in limiting how acidic the fluids surrounding them become.
- This living pump is a chambered organ, lined by the smoothest of vascular endotheliums, made up of a hive of ever-beating cells of a unique variety: cardiac muscle cells. The beating of these muscle fibers is co-ordinated by its own electrical conductive system.
- Though the heart is, in many ways, self-contained, able to beat on even if removed from the body - it is also fully co-ordinated into our bodies, centered in our chest, responsive to the hormones released by our mood - and by chemicals that result from our activities; responsive, too, to the very pressure and contents of the blood it moves.
