Mounds in the water form in areas where the water meets land, where water is warmer, or where two currents converge. Gravity then pushes this water down slope on the mounds and creates currents. Deep water currents, also called thermohaline circulation, are found below 400 meters and make up about 90% of the ocean. Like surface currents, gravity plays a role in the creation of deep water currents but these are mainly caused by density differences in the water.
The pacemaker of the heart is a bundle of cells that tells the  heart when to beat. These cells are connected to the rest of the  cells of the heart and communicate with theâ¦m through electrical  signals. The pacemaker cells set the pace (or rate) of the  heartbeat.    The actual structure that serves as the heart's primary pacemaker  is called the sinoatrial node (SA node).
Pacemakers do not take over the work of the heart. After you have a pacemaker, your heart still does all its own work. Rather, the pacemaker merely helps to regulate the timing and sequence of of your heart beat. Pacemakers consist of two major parts: the generator and the leads. The generator is essentially a tiny computer (along with a battery and other electronic components), housed in a hermetically sealed titanium container.