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.
In a tight junction, a series of integral protein molecules in the plasma membranes of adjacent cells fuse together, forming an impermeable junction that encircles the cell. Tight junctions help prevent molecules from passing through the extracellular space between adjacent cells.