peripheral motor neuron. Etymology: Gk, periphereia + L, motor, mover; Gk, neuron, nerve. an effector neuron located outside the central nervous system, usually in a ganglion of the sympathetic or parasympathetic nervous system.
Gneiss rock is further characterized by its alternating light and dark bands of minerals. Gneiss forms from volcanic rock, shale, or granitic. Quartz is typically abundantly found in gneiss. The bands that form on gneiss rock are due to the various rocks that are a part of its make-up. The use of the word gneiss dates back to the mid-1700s. Gneiss rocks that originate as sedimentary rock are called paragneiss and those originating as igneous rock are called orthogneiss. Limestone can change into calcareous gneiss which contains calcium carbonate.
1 Gneiss can be formed from a sedimentary rock such as sandstone or shale, or it can be formed from the metamorphism of the igneous rock granite. 2  Gneiss can be used by man as paving and building stone.3  Marble is metamorphosed limestone or dolomite. The minerals that compose gneiss are the same as granite. 2  Feldspar is the most important mineral that makes up gneiss along with mica and quartz. 3  Gneiss can be formed from a sedimentary rock such as sandstone or shale, or it can be formed from the metamorphism of the igneous rock granite.