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.
Gneiss, a foliated metamorphic rock. Marble, non-foliated metamorphic rock. Examples of foliated and non-foliated metamorphic rocks are shown above. On the left is gneiss, showing minerals aligned along visible planes typical of foliated metamorphic rocks. Gneiss can form from the metamorphism of granite.On the above right is a picture of marble, a typical non-foliated metamorphic rock.xamples of foliated and non-foliated metamorphic rocks are shown above. On the left is gneiss, showing minerals aligned along visible planes typical of foliated metamorphic rocks. Gneiss can form from the metamorphism of granite. On the above right is a picture of marble, a typical non-foliated metamorphic rock.