Neural oscillation sinoatrial node normally initiates it, simply because it generates impulses slightly faster than the other areas. Hence, these cells generate the normal sinus rhythm and are called pacemaker cells as they directly control the heart rate. In the absence of extrinsic neural and hormonal control, cells in the SA node will rhythmically discharge. The sinoatrial node is richly innervated by the autonomic nervous system, which up or down regulates the spontaneous firing frequency of the pacemaker cells. Synchronized firing of neurons also forms the basis of periodic motor commands for rhythmic movements. These rhythmic outputs are produced by a group
Blank node the blank node indicates an 'unknown' URI. From a technical perspective they give the capability to: Below there is an example where blank nodes are used to represent resources in the aforementioned ways. In particular, the blank node with the identifier '_:students' represents a Bag RDF Container, the blank node with the identifier '_:address' represents a complex attribute and those with the identifiers '_:activity1' and '_:activity2' represent events in the lifecycle of a digital object. The ontology language OWL uses blank nodes to represent anonymous classes such as unions or intersections of classes, or classes called restrictions, defined by a