Question

When the rectum fills, the defecation reflex in initiated. Describe the events that occur during the defecation reflex.

Answer 1

Explanation:

Peristaltic movement is responsible for pushing the fecal matter from the sigmoid colon to the rectum . This results in the distension in the rectum by which the stretch receptors are stimulated .

The information is carried by the sensory neuron from the receptors to the spinal cord and the motor nerve bring information from the cord to the descending colon then to the sigmoid colon and then rectum, and finally to anus , which results in the contraction of longitudinal rectal muscles which decreases the rectum and thereby the pressure increases within the rectum leading to opening of internal sphincter .