The premotor cortex is dysgranular: it contains a faint layer IV. The premotor cortex can be distinguished from Brodmann area 46 of the prefrontal cortex, just anterior to it, by the presence of a fully formed granular layer IV in area 46.The premotor cortex is therefore anatomically a transition between the agranular motor cortex and the granular, six-layered prefrontal cortex.he premotor cortex occupies the part of Brodmann area 6 that lies on the lateral surface of the cerebral hemisphere. The medial extension of area 6, onto the midline surface of the hemisphere, is the site of the supplementary motor area, or SMA.
A Nilos ring is an external metal bearing seal that produces a small labyrinth like sealing surface on the inner or outer ring of a bearing. When mounted in pairs, the bearing is sealed for life.
Ring system. A ring system is a disc or ring orbiting an astronomical object that is composed of solid material such as dust and moonlets, and is a common component of satellite systems around giant planets. A ring system around a planet is also known as a planetary ring system.