AP BIOLOGY

Detailed explanation-1: -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-2: -Signals that act locally between cells that are close together are called paracrine signals. Paracrine signals move by diffusion through the extracellular matrix. These types of signals usually elicit quick responses that last only a short amount of time.

Detailed explanation-3: -Juxtacrine signaling occurs between neighboring cells that are in physical contact with each other. In this case, the signaling molecule is not free, but is instead bound to the membrane of the cell. It may then interact with a receptor on the membrane of an adjacent cell.

Detailed explanation-4: -autocrine signaling: produced by signaling cells that can also bind to the ligand that is released: the signaling cell and the target cell can be the same or a similar cell (prefix auto-means self) paracrine signaling: a form of cell signaling in which the target cell is near (para = near) the signal-releasing cell.

Detailed explanation-5: -Paracrine Signaling Promotes Blood Clotting Broken endothelial tissue releases von Willebrand factor (vWF), which binds to platelets-small white blood cells without nuclei-circulating in the blood. This is a form of paracrine signaling.