They make up the cardiac pacemaker, that is, the natural pacemaker of the heart. In most humans, the concentration of pacemaker cells in the sinoatrial (SA) node is the natural pacemaker, and the resultant rhythm is a sinus rhythm. Sometimes an ectopic pacemaker sets the pace, if the SA node is damaged or if the electrical conduction system of the heart has problems.
Use IE Tab for Chrome. The best way to use Java (or Silverlight, or other NPAPI-based technologies) going forward is to use IE Tab for Chrome. You can set up Auto URLs to automatically open certain urls using IE Tab, providing a seamless experience, as if Java support never went away. Get it here:
Launch for Java. Use Default Browser to Open a Web Page from a Swing Application. Launch the user's default browser and open a web page from a Java application with the code below. The above code uses the Desktop library introduced in Java 6, so it will not work with Java 5. However, the Bare Bones Browser Launch solution is designed to work on Java 5.