Pacemaker current on hyperpolarization, and very slow kinetics. The funny current is highly expressed in spontaneously active cardiac regions, such as the sinoatrial node (SAN, the natural pacemaker region), the atrioventricular node (AVN) and the Purkinje fibres of conduction tissue. The funny current is a mixed sodium–potassium current that activates upon hyperpolarization at voltages in the diastolic range (normally from −60/−70 mV to −40 mV). When, at the end of a sinoatrial action potential, the membrane repolarizes below the I threshold (about −40/−50 mV), the funny current is activated and supplies inward current, which is responsible for starting the diastolic depolarization phase
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