We dissected sheep hearts in class today. When I led this same dissection lab two years ago, I studied and poured over youtube videos and diagrams. This year a Navy nurse friend of mine led the presentation and dissection which made me realize I knew absolutely nothing. I was like a child reciting ABC’s, “Right Atrium, Right ventricle…”. I would have her back again tomorrow just so I could listen to her talk…about anything medical related. It was like having a real live“explain it like I’m five” person.
It sent me down a research spiral. Did you know that the heart of a baby fetus starts beating independent of the brain? I knew the heart always had its own electrical muscle, but I always assumed it went hand in hand with brain development inside the womb. They studied mice fetus hearts to see if they could break down exactly when that first “Spark of life” happens (pun intended?). They thought they had it figured out, but then surprise.
"We were surprised to find that calcium activity preceded the assembly of the machinery that does the contraction. You could imagine that the contraction machinery would have been in place first, waiting for the calcium signal to arrive, but in fact it was the other way around," said Shankar Srinivas, a professor of developmental biology at the University of Oxford, who co-led the study.
Hmmm… it’s almost like there really is a divine spark.
The calcium waves start off haphazardly in cells far apart, like lost fireflies. But then quickly—within a couple of hours—they come together to pulse in synchrony at a point when the beating becomes visible for the first time. Researchers want to find out how this switch occurs to be able to make functional heart tissue in the lab and to better understand heart disease.
