OBSOLETE. The pathway along which proteins and other substances are moved around and out of the cell. After synthesis on the ribosomes of the endoplasmic reticulum (ER), completed polypeptide chains are moved to the Golgi complex and subsequently sorted to various destinations. Proteins synthesized and sorted in the secretory pathway include not only those that are secreted from the cell but also enzymes and other resident proteins in the lumen of the ER, Golgi, and lysosomes as well as integral proteins in the membranes of these organelles and the plasma membrane.