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.
A gap junction is a communicating junction between adjacent cells. At gap junctions the adjacent plasma membranes are very close, and the cells are connected by hollow cylinders called connexons, composed of transmembrane proteins.