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.
White Blood cells or WBC's are the cells of your immune system. They are your first defense in fighting off foreign invaders and infectious diseases.
-Medical Student (College Level)
