<P> Tight junctions are composed of a branching network of sealing strands , each strand acting independently from the others . Therefore , the efficiency of the junction in preventing ion passage increases exponentially with the number of strands . Each strand is formed from a row of transmembrane proteins embedded in both plasma membranes , with extracellular domains joining one another directly . Although more proteins are present , the major types are the claudins and the occludins . These associate with different peripheral membrane proteins such as ZO - 1 located on the intracellular side of plasma membrane , which anchor the strands to the actin component of the cytoskeleton . Thus , tight junctions join together the cytoskeletons of adjacent cells . </P>
where can tight junctions be found in the body
the cytoskeletons of adjacent cells