Sinoatrial node action potentials, so that it can pass throughout the heart and cause contraction. An action potential is a change in voltage (membrane potential) across the membrane of the cell, produced by the movement of charged atoms (ions). Non-pacemaker cells (including the ventricular and atrial cells) have a period, immediately after an action potential, where the membrane potential remains relatively constant; this is known as a resting membrane potential. This resting phase (see cardiac action potential, phase 4) ends when another action potential reaches the cell. This produces a positive change in membrane potential (known as depolarisation), which initiates the start
Node graph architecture Node graph architecture Node graph architecture is a type of software design which builds around modular node components which can be connected to form a graph. Often the software's underlying node graph architecture is also exposed to the end user as a two-dimensional visualization of the node graph. The node graph architecture is popular in the film and computer games industry. There are often many different node types participating in the node graph. For example, in the Nuke Manual they list hundreds of nodes. Each node type performs one specific task. For example, Nuke's Merge node produces an output image