Tips. 1  If you want to focus on a particular muscle area, you can do so by changing the stride length. 2  For an elliptical with multiple users, use one whose stride length is adjustable to accommodate different heights. 3  Do not rely solely on guidelines.
3. Intercellular chemical signals secreted into the circulatory system; carried to organs they control, where they bind to receptors and produce a response. 4. Intercellular chemical signals, secreted by nerve cells; important in the function of the nervous system.
Cell-to-cell signals take two forms, and these are the topic of the two main divisions of this. chapter: Chemical signals are proteins, lipids, or even. gases secreted by cells that prompt an effect in neigh-. boring or distant cells.