Early in gestation the fetal heart rate is predominately under the control of the sympathetic nervous system and arterial chemoreceptors [1]. As the fetus develops its heart rate decreases in response to parasympathetic ( vagal stimulation) nervous system maturation and variability becomes more pronounced [2].
Igneous Rocks by Composition Igneous rocks are classified according to their mineral content: Ultramafic rocks are dominated by olivine and/or pyroxene. Mafic rocks are dominated by plagioclase and pyroxene (even if you can't see them with the naked eye) and smaller amounts of olivine.Intermediate rocks are roughly even mixtures of felsic minerals (mainly plagioclase) and mafic minerals (mainly hornblende, pyroxene, and/or biotite).There is little or no quartz. Felsic rocks are mostly feldspar (especially K-feldspar), at least 10% quartz, and less than 15% mafic minerals (biotite, hornblende).afic rocks are dominated by plagioclase and pyroxene (even if you can't see them with the naked eye) and smaller amounts of olivine. Intermediate rocks are roughly even mixtures of felsic minerals (mainly plagioclase) and mafic minerals (mainly hornblende, pyroxene, and/or biotite).
intermediate (adj) a substance formed during a chemical process before the desired product is obtained. intermediate (adj) lying between two extremes in time or space or state going from sitting to standing without intermediate pushes with the hands; intermediate stages in a process; intermediate stops on the route; an intermediate range plane