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.
The endocrine system is a system of ductless glands that secrete hormones directly into the circulatory system to be carried long distances to other target organs that regulate key body and organ functions. Some endocrine glands secrete into a portal system rather than the systemic circulation that allows for the direct targeting of hormones.