AP BIOLOGY

Detailed explanation-1: -Local regulators help regulate blood pressure, nervous system function, and reproduction. • Local regulators are divided into two types: – Paracrine signals act on cells near the secreting cell. – Autocrine signals act on the secreting cell itself.

Detailed explanation-2: -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-3: -These cells secrete their signal molecules, called hormones, into the bloodstream, which carries the signal to target cells distributed widely throughout the body (Figure 15-4D). The mechanisms that allow endocrine cells and nerve cells to coordinate cell behavior in animals are compared in Figure 15-5.

Detailed explanation-4: -In paracrine signaling, a molecule released by one cell acts on neighboring target cells.