The defecation reflex involves two postive feedback loops. these loops are the stretch receptors in the rectal walls and the sacral parasympathetic system. Defecation reflex empties the rectum by peristaltic movements push fecal matter from the sigmoid colon into the rectum. Then this distension of the rectal walls stimulates stretch receptors which results in defecation.
It is transplanted routinely to treat a variety of blood and bone marrow diseases, blood cancers, and immune disorders. More recently, stem cells from the blood stream (called peripheral blood stem cells) and umbilical cord stem cells have been used to treat some of the same blood-based diseases
Hydrologists measure the properties of bodies of water. For example, volume and stream flow.
The correct answer would be d.
