Vesicle
The endoplasmic reticulum is one of the organelles found in all eukaryotic cells, and consists of a network of tubules, vesicles, and cisterna. The endoplasmic reticulum is made up of proteins and is distributed throughout the cell (the prokaryote does not have a cell organelle, so it does not have an endoplasmic reticulum). The basic structure and organization of the endoplasmic reticulum is the extension of the nuclear membrane (endomembrane system) Similar to normal cell membranes. The endoplasmic reticulum is composed of proteins (transmembrane receptors or intracellular proteins) to be part of the cell membrane, synthesis of proteins to be secreted out of the cell (ie digestive enzymes, calcium adsorption, synthesis / storage of glycogen and steroids or macromolecules) Structure formation, and transportation. The endoplasmic reticulum in the muscle is called the sarcoplasmic reticulum.