Not to be confused with Retinal. Retinol, also known as Vitamin A1, is a vitamin found in food and used as a dietary supplement. As a supplement it is used to treat and prevent vitamin A deficiency, especially that which is resulting in xerophthalmia.
Desmosomes are anchoring junctions â mechanical couplings scattered like rivets along the sides of adjacent cells to prevent their separation. On the cytoplasmic face of each plasma membrane is a thickening called a plaque.
Tight junctions are the closely associated areas of two cells whose membranes join together to form a virtually impermeable barrier to fluid. Tight junctions perform vital functionsâsuch as holding cells togetherâand form protective and functional barriers. Tight junctions are composed of a branching network of sealing strands with each strand acting independently from the others. The major types of proteins in junctions are the claudins and the occludins.