In this lecture, I am going to discuss about Desmosomes and Adherence Junction. Men points of the lesson are Structure of Desmosomes and Adherence Junction, Caterence, Cider Plasmaic Plac, Intermediate Filaments and Roll of Calcium Iines. Desmosomes are the points of attachment between two cells. Once we have two animal cells, they are bounded by Plasma Membrane. This is the Plasma Membrane of cell I and this is the Plasma Membrane of cell II. And these two cells are attached by Desmosomes. Then Desmosomes originated from two ancient Greek words that is Desmos and Soma. Desmos means Bound and Soma means Body. Desmosomes are present in Appithelial cells and Muscle cells. Structure of Desmosomes. Desmosomes are composed of three components. Number one is Trans Membrane Adhesion Protein that is called Adherence. Number two anchor protein that is called Cider Plasmaic Plac, which is present inside the cell membrane. And number three is here Intermediate Filaments. Trans Membrane Adhesion Proteins that is called Ciderence. They are found on the membranes of two cells and the main portions are located here in Extra Cellular Space, present between the Plasma Membrane of Adjacent cells. So, Extra Cellular Part of One Cells Ciderence bind to Extra Cellular Part of Adjacent cells Ciderence in the space between the two cells. Ciderence interact in the space between them holding the two membranes together. And each cells Ciderence molecule contains a tail and that tail insert itself into the respective cell. Inside the cell Ciderence tail attach to a disc of dense protein structure that is called Cider Plasmaic Plac, which is read in image at white and left and this Cider Plasmaic Plac, which connects to cells, internal skeletal framework that is intermediate microfilaments and helps to anchor the junction. Desmosomes connect the adjacent cells together and ensuring that the cells in organs and tissues that stretch as in case of skin and cardiac muscle they remain connected as unbroken sheets. In epithelial cells these junctions are small disc-shaped and they are called spot welds between the adjacent cells. Desmosomes which are present in heart are more complicated because they are mixed with adherence junction. Now what is the difference between adherence junction and desmosomes? In desmosomes, ciderherence connect to cytoplasmic intermediate filaments but in case of adherence junction, ciderplasmaic actin filaments. So the difference between adherence junction and desmosomes is intermediate filaments and actin filaments. Intermediate filaments are present in case of desmosomes and actin filaments are present in case of adherence junction. Advantage of desmosomes that they hold the cells together at one point as are revert or spot welds. Desmosomes allow cells to form strong sheets and substances still pass freely through the intercellular spaces between the plasma membrane. What is the role of calcium ions in adherence junction? The external cellular portions of ciderherence molecules of adjacent cells are bound together by calcium ions or another protein in some cases. This means that functional as well as morphological integrity of adherence junctions are calcium dependent. If you remove calcium from the junction, this type of cell junction would disintegrate.