Cardiac pacemaker in adult humans is about 70 beats per minute. Because the sinoatrial node is responsible for the rest of the heart's electrical activity, it is sometimes called the "primary pacemaker". If the SA node does not function properly and is unable to control the heart rate, a group of cells further down the heart will become the ectopic pacemaker of the heart. These cells form the Atrioventricular node (or AV node), which is an area between the left atrium and the right ventricle within the atrial septum, will take over the pacemaker responsibility. The cells of the AV node normally
Common name objects, typically an incomplete and informal classification, in which some names are degenerate examples in that they are unique and lack reference to any other name, as is the case with say, "ginkgo", "okapi", and "ratel". Folk taxonomy, which is a classification of objects using common names, has no formal rules and need not be consistent or logical in its assignment of names, so that say, not all flies are called flies (for example Braulidae, the so-called "bee lice") and not every animal called a fly is indeed a fly (such as dragonflies and mayflies). In contrast, scientific or biological