What is the difference between Zonula adherens and Macula adherens?
Epithelial cells are held together by strong anchoring (adherens) junctions. macula adherens (desmosomes) which contain intermediate filaments. The zonula adherens junction lies below the tight junction (occluding junction). The cadherins from adjacent cells interact to ‘zipper’ up the two cells together.
What is the difference between desmosome and adherens junctions?
A fundamental difference is that desmosomes have a highly ordered structure in their extracellular region and exhibit calcium-independent hyperadhesion, whereas adherens junctions appear to lack such ordered arrays, and their adhesion is always calcium-dependent.
In what way are desmosomes similar to Hemidesmosomes?
Desmosomes and hemidesmosomes are membrane-bound structures that act as adhesion structures. Desmosomes act as cell to cell adhesions while hemidesmosomes act as adhesions that form between cells and the basement membrane.
Where are Zonula Occludens found?
Tight junctions, or zonula occludens (ZO), are characteristic of epithelial and endothelial cells (Figure 1). Located at the border between apical and lateral membranes, tight junctions regulate the passage of proteins and liquids across the cell monolayer.
Why do kidney and bladder need a tight junction?
tight junctions encircle adjacent epithelial cells preventing the unregulated flux of ions, organic solutes, and water across the paracellular space. The umbrella cells form the urine-contacting layer of the stratified uroepithelium that lines the mucosal surface of the urinary bladder, ureters, and renal pelvis.
Are tight junctions found in the heart?
Adherens junctions are involved in a number of critical functions, including providing additional structural support. For example, they hold cardiac muscle cells tightly together as the heart expands and contracts.
What is an example of tight junction?
Examples of tight epithelia include the distal convoluted tubule, the collecting duct of the nephron in the kidney, and the bile ducts ramifying through liver tissue. Other examples are the blood-brain barrier and the blood cerebrospinal fluid barrier.
What is the function of tight junction?
Tight junctions form the continuous intercellular barrier between epithelial cells, which is required to separate tissue spaces and regulate selective movement of solutes across the epithelium.