@praveen s
Cell Junctions are interconnections of adjacent cells through their plasma membrane. These are specialization of plasma membrane due to cell to cell contacts. The two adjacent membranes when come close to each other, interact to form cell junctions. They are also called as Intercellular junctions.
The Cell junctions are broadly classified into three types;
1.Occluding junctions
2.Anchoring junctions
3.Ion channels.
Occluding Junctions
Cell junctions where the two membranes are close together but fuse with each other are called occluding junctions. Occluding junctions prevent the passage of molecules between cells. These occluding junctions are of two types.
1.Tight Junctions
2. Septate Junctions
Anchoring junctions
Anchoring Junctions are mechanical connections of the cytoskeletal structures of one cell to the cytoskeletal elements of other cell or to the extracellular matrix. They are found in heart muscles and skin epithelium.
Anchoring junctions are of two types;
1.Adherens junctions
2.Desmosomes.
Ion Channels
Ion channels are small pore complexes present in plasma membrane. They are formed by pre -forming proteins to establish and control a small voltage gradient across the plasma membrane of all living cells. They are allowing the flow of ions down their electrochemical gradient.