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.
Glands and Tissues that produce Hormones. Hormones are chemicals (sometimes called chemical messengers) that are produced (synthesized) and released (secreted) by the endocrine system. In many cases hormones are secreted by the main endocrine glands in the human body.