MEDICAL PHYSIOLOGY

Detailed explanation-1: -Receptors are generally transmembrane proteins, which bind to signaling molecules outside the cell and subsequently transmit the signal through a sequence of molecular switches to internal signaling pathways.

Detailed explanation-2: -Ligands can thus be thought of as signaling molecules. Ligands interact with proteins in target cells, which are cells that are affected by chemical signals; these proteins are also called receptors.

Detailed explanation-3: -Paracrine signaling Often, cells that are near one another communicate through the release of chemical messengers (ligands that can diffuse through the space between the cells). This type of signaling, in which cells communicate over relatively short distances, is known as paracrine signaling.

Detailed explanation-4: -Regardless of the nature of the signal, the target cell responds by means of a specific protein called a receptor, which specifically binds the signal molecule and then initiates a response in the target cell.

Detailed explanation-5: -Chemical signals between cells are called ligands. A ligand is a molecule that binds another specific molecule. In the case of cell signaling, the ligand binds a receptor, a protein in or on the target cell. Examples of ligands include hormones and neurotransmitters.