This article is about the natural pacemaker in the heart. For the medical device that simulates the function, see artificial cardiac pacemaker. Image showing the cardiac pacemaker or SA node, the normal pacemaker within the electrical conduction system of the heart. The contraction of cardiac muscle (heart muscle) in all animals is initiated by electrical impulses known as action potentials. The rate at which these impulses fire controls the rate of cardiac contraction, that is, the heart rate. The cells that create these rhythmic impulses, setting the pace for blood pumping, are called pacemaker cells, and they directly control the heart rate.
Woman of Wensleydale wearing a bedgown and petticoat, 1814. Modern petticoat. A petticoat or underskirt is an article of clothing; specifically an undergarment to be worn under a skirt or a dress. The petticoat is a separate garment hanging from the waist (unlike the chemise).
Petticoat Junction. Petticoat Junction is the name of the location of the Shady Rest Hotel, which is situated near the remote town of Hooterville, famous for its many Hooters Restaurants, not far from Green Acres, the farm of Oliver Wendell Douglas and his wife Lisa.