Endoplasm, also known as entoplasm, generally refers to the inner, dense part of a cell's cytoplasm. The nucleus is separated from the endoplasm by the nuclear envelope. In an amoeba and other protist
This is a perikaryon of a nerve cell, displayed here because of the obvious cytoplasmic granules. The granules, which appear almost black due to their high electron density, take up a large portion of the endoplasm. They are suspended in cytosol - the fluid component of the cytoplasm.
Shown is a micrograph of an amoeba; the darker pink nucleus is central to the eukaryotic cell, with the majority of the rest of the cell's body belonging to the endoplasm. Though not visible, the ectoplasm resides directly internal to the plasma membrane.