Inferior vena cava. The inferior vena cava (or IVC) (Latin: vena, vein, cavus, hollow) is a large vein that carries deoxygenated blood from the lower and middle body into the right atrium of the heart. Its walls are rigid and has valves so the blood does not flow down via gravity.
Tight Junctions The tight junction (also referred to as a zonula occludens) is a site where the membranes of two cells come very close together. In fact, the outer leaflets of the membranes of the contacting cells appear to be fused. Tight junctions, as their name implies, act as a barrier so that materials cannot pass between two interacting cells.
Gap junctions. Gap junctions. connections between cells which allow passage of small molecules and electric current. Gap junctions were first described anatomically as regions of close apposition between cells with a narrow (1-2 nm) gap between cell membranes. The variety in the properties of gap junctions is reflected in the number of connexins, the family of proteins which form the junctions. Please contribute to this project, if you have more information about this term feel free to edit this page.