Let me share a page or so of my friend Brian Doyle's marvelous little book The Wet Engine (2005), which is both an account of the heart surgery that saved the life of his infant son, born with a three-chambered heart, and a song of praise for the heart itself and the wizard physicians who mend them.
Consider the astounding journey your blood embarks upon as it enters the pumping station of your heart. It is a healthy heart, a heart that works as it has been designed to work over many millions of years by its creative and curious and tireless and nameless holy wild silent engineer, blood that has been plucked and shucked of its oxygen by the body straggles back into the right atrium, the capacious gleaming lobby of the heart.Brian's exuberant prose (which always rubs off on me) matches the exuberance with which he embraces life, life that he doesn't hesitate to call holy, and joyous, and mysterious, and wild. I always love to read his stuff, which seems to pop up everywhere in print, at least in the print I have the habit of visiting, because he has a way of reminding me just how holy and joyous and mysterious is the utterly commonplace, such as that utterly commonplace organ pumping away in my chest, so far infallibly, maybe two or three billion heaves so far, may it keep heaving for another few hundred million beats. Thanks, Brian, for reminding me that it's all gape-jawed marvelous, and that knowing more and more about how it works in no way diminishes the gape-jawed marvel but brings a prayer to the lips, not a petition to Mr. Big, not a cry for attention ("Me, Lord, me."), but a simple spontaneous undirected litany of praise and thanksgiving that gets longer and longer the more we learn, may it never end.
The tired blood, dusty veteran of an immense and exhausting journey, shuffles forward to and through a small circular door in the wall, a door with three symmetrical flaps: the tricuspid valve.
This circular door opens into another big room, the right ventricle; but at the very instant the right ventricle is filled to capacity with tired blood the entire ventricle contracts! slamming in on itself, and our tired heroes are sent flying through the pulmonary valve and thence into the pulmonary artery, which immediately branches, carrying the blood to the right and left lungs, and there, in the joyous airy countries of the blood vessels of the lungs, your blood is given fresh clean joyous oxygen! gobs and slathers of it! o sweet and delicious air! as much as those heroic blood cells can hoist aboard their tiny cellular ships, and now they resume their endless journey, heading into the marshlands and swamps of the lungs, the capillary beds, which open into the small streams and creeks called venules, which are tributaries of the pulmonary veins. There are four of these magic pulmonary rivers carrying your necessary elixir back to the looming holy castle of the heart, which they will enter this time through the left atrium, whose job is to disperse and assign the blood to the rest of the body, to send it on its quest and voyage and journey to the vast and mysterious wilderness that is You, and to tell that tale of the journeys of your blood cells through the universe of you, would take a billion books, each alike, each utterly different.