It depends the organ and tissue. But what it is outside cells its called extracellular matrix (EMC), which is a collection of extracellular molecules secreted by cells that provides structural and biochemical support to the surrounding cells. read more
In the gap between two adjacent cells, a glycoprotein is filled and keratin filaments run from the cytoplasm of both cells crossing their plasma membranes and intercellular space. d. Gap junctions Connexin proteins from two cells align in such a manner as to form connexons, which is a fancy name for channel between the two cells. read more
Small intestines contain tight junctions that prevent corrosive digestive enzymes that are within the lumen of the intestine from moving between cells and damaging internal body structures. read more