What is the mechanism by which they adhere to each other, and what stops them from sticking together when say you put your hands together?
Cell adhesion is the process by which cells bind to each other or to the extracellular matrix (ECM), forming tissues and organs in multicellular organisms. It is essential for maintaining the structural integrity of tissues, as well as for cellular communication and signaling.
There are several mechanisms by which cells can adhere to each other, including physical interactions such as direct contacts, cell junctions, and extracellular matrix interactions. These interactions involve specialized proteins and molecules that facilitate cell adhesion.
Cell junctions are specialized structures that connect cells to each other and to the extracellular matrix. There are three main types of cell junctions: tight junctions, adherens junctions, and desmosomes. These junctions rely on different proteins, such as cadherins, to mediate adhesion between cells.
The extracellular matrix (ECM) is a complex network of proteins and carbohydrates that surrounds cells and provides structural support. It also plays a crucial role in cell adhesion, as many cell surface receptors bind to specific components of the ECM, such as fibronectin and collagen.
Cell adhesion is essential for embryonic development and tissue formation, as it allows cells to organize into specific structures and perform their specialized functions. Alterations in cell adhesion can also lead to diseases, such as cancer, where cells lose their ability to adhere properly and can spread to other parts of the body.