Connections of the Heart
The Beat of a Single Cell
We may not immediately think of our heart as a collection
of individual cells. But it is the complex interaction of numerous cell types that give
the heart its ability to pump blood. Some cells form heart connective tissue, other cells
grow into heart valves. And muscle cells give the heart its ability to beat and pump blood
throughout the body.
You can dissolve an embryonic heart into its individual cell
types with trypsin, an enzyme that destroys the protein glue between the cells. Plate
these cells in a dish and you will see some cells - called myocytes
- that beat independently. The cells shown here are from the chick embryo.
A single cell beats when a complex series of gates -
called ion channels - open and close in
an organized manner. Cell physiologists can measure how these ion channels work using a
technique called the patch clamp.