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.
Problem 13: Cell junctions. The cell junctions respectively that exclude the passage of water between cells, maintain tissue form and strength, and allow the exchange of small molecules between cells are: Cell junctions. Graphic of junctions in animal cells. Tight junctions. Tight junctions block the flow of fluids between epithelial cells. For example, the cells that line the intestine are responsible for taking up nutrients from the gut. The nature of the material taken up must be controlled to block unwanted substances from entering our bodies. The control comes from the fact that materials must pass through receptors on the epithelial cell membranes.