Final answer:
Paralytic ileus is defined as the stoppage of intestinal muscle movements that normally propel digestive contents through the gut. It is in contrast to the normal regulatory mechanisms of bowel motility, including the gastroileal reflex, hormonal releases of gastrin and motilin, and ultimately coordinated movements such as peristalsis in the digestive tract.
Step-by-step explanation:
The term paralytic ileus refers to the cessation of peristalsis, which is the wave-like muscle contractions responsible for moving food through the digestive tract. In a paralytic ileus, there is a lack of intestinal muscle movement, which can lead to a buildup of food residue and possibly cause obstructions. This can happen due to various reasons, including postoperative complications or an imbalance in the body's electrolytes. Typically, peristalsis is regulated by a collection of reflexes and hormones such as the gastroileal reflex and gastrin, which increase motility in the ileum and facilitate the relaxation of the ileocecal sphincter allowing chyme to move from the ileum to the large intestine. Additionally, the hormone motilin plays a critical role in initiating peristalsis within the small intestine. Contrarily, in the large intestine, movement is orchestrated through haustral contractions, peristalsis, and mass movements aided by the gastrocolic reflex. A disruption in these processes can result in paralytic ileus.