Sinoatrial node of the next action potential. Pacemaker cells, however, don’t have this resting phase. Instead, immediately after one action potential, the membrane potential of these cells begins to depolarise again automatically, this is known as the pacemaker potential. Once the pacemaker potential reaches a set value, known as the threshold value, it then produces an action potential. Other cells within the heart (including the purkinje fibers and atrioventricular node; AVN) can also initiate action potentials; however, they do so at a slower rate and therefore, if the SA node is working, it usually beats the AVN to it. Outlined below are
Node (computer science) the constant properties for a node, this property specifies the type of the node. So if a node type property is the constant node ELEMENT_NODE, one can know that this node object is an object Element. This object uses the Element interface to define all the methods and properties of that particular node. Node Types Different W3C World Wide Web Consortium node types and descriptions: A node object is represented by a single node in a tree. It can be an element node, attribute node, text node, or any type that is described in section "node type". All objects can