 Desmosomes are extracellular protein structures responsible for cellular adhesion, whereby cells of the same type are held closely together.Gap junctions are specialized channels located within the cell membrane of many animal cell types, which serve as gateways that connect the cytoplasmic interior of two adjacent cells, allowing the passage of small molecules such as ions, nucleotides, second messengers and others.The movement and exchange of small molecules between cells is an important part of intracellular communication processes like cell signaling.