Tag Archives: Chapter 46.1: Circulatory and Respiratory Systems

How Blood Flows Through the Heart

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"Computer models of the heart incorporate detailed experimental information, both at the level of individual cells and at the level of anatomy. Here, a model developed by Peter Hunter’s team at the University of Auckland portrays the changing orientation of the heart’s muscle fibers from the outside to the inside of the heart wall. The spiraling of the fibers is believed to affect the flow of electric signals through the heart. Courtesy of Peter Hunter, PhD, Bioengineering Institute, The University of Auckland, New Zealand."--Via.

“Computer models of the heart incorporate detailed experimental information, both at the level of individual cells and at the level of anatomy. Here, a model developed by Peter Hunter’s team at the University of Auckland portrays the changing orientation of the heart’s muscle fibers from the outside to the inside of the heart wall. The spiraling of the fibers is believed to affect the flow of electric signals through the heart. Courtesy of Peter Hunter, PhD, Bioengineering Institute, The University of Auckland, New Zealand.”–Via.

The following video accounts for how blood gets oxygen. Veins and arteries trace pathways; the heart is a pump that relays oxygenated blood to the rest of our bodies. While you observe this video, keep in mind that the heartbeat is regulated by electricity; it obeys a continuous rhythm that has never stopped.

From a cardioid to a Jarvik: the human heart and its understanding across millenia.

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Sacred Heart

Sacred Heart

Someone in class asked me a few days ago–I don’t remember who–why the heart symbol (known as a cardioid) does not resemble an actual heart. I do not know the exact answer to this question, but maybe some historical context on the cardioid might shed some light on the subject (via Lapham’s Quarterly):

The ♥ icon is used all over the world as a pictogram of the human heart, and as shorthand for affection: ♥ = heart = love. It is the most commonly recognised symbol on the planet after the cross and the crescent. But though we see it all the time, and teach its meaning to our children, its associations with the organ of circulation, and indeed love, are neither ancient nor instinctive. The ♥ shape has represented a variety of things across different cultures over time, ranging from genitalia to cosmic wisdom; the heart, meanwhile, was an enigmatic organ for most of history, whose biological function was not understood until 1628; and the emotion of love, if associated with flesh instead of mind or spirit, was equally likely to be linked to the eyes, the head, or the liver as to the heart. The story of how the ♥, the heart, and love came together is a romantic tale.

After more than 1,500 years, we can finally say that the heart has nothing to do with the cardioid–the heart symbol. From believing that a heart resembles a shape that does not account for what it actually looks like, we have actually mimicked the mechanics of a beating heart. Maybe this mechanic –cyborg like– heart is not as romantic as the ancient cardioid; but it has definitively improved the quality of life of many people:

"Graphic of the SynCardia temporary Total Artificial Heart beside a human heart with call-outs."

“Graphic of the SynCardia temporary Total Artificial Heart beside a human heart with call-outs.”