剑桥医学英语 Lesson 20-Supplementary Text (Intestinal obstruction —Part 2)

Paralysis, or adynamic, obstruction results from neurogenic or muscular impairment of peristalsis. Paralytic ileus is seen most commonly after abdominal surgery. It also accompanies inflammatory conditions of the abdomen, intestinal ischemia, pelvic fractures and back injuries. It occurs early in the course of peritonitis and can result from chemical irritation caused by bile, bacterial toxins, electrolyte imbalances as in hypokalemia, and vascular insufficiency.

The major effects of both types of intestinal obstruction are abdominal distension and loss of fluids and electrolytes. Gases and fluids accumulate within the area; if untreated, the distention resulting from bowel obstruction tends to perpetuate itself by causing atony of the bowel and further distention. Distention is further aggrevated by the accumulation of gases. About 70% percent of these gases are derived from swallowed air. As the process continues, the distention moves proximally, involving additional segments of bowel. Either form of obstruction may eventually lead to strangulation, gangrenous changes, and ultimately perforation of the bowel. The increased pressure within the intestine tends to compromise mucosal blood flow, leading to necrosis and movement of blood into the luminal fluids. This promotes rapid growth of bacteria within the obstructed bowel. Anaerobes grow rapidly in his favorable environment and produce a lethal endotoxin.

paralysis                   麻痹，瘫痪   

adynamic                  动力缺失的

neurogenic                神经原（性）的

peristalsis                  蠕动 

peristaltic                   蠕动的

paralytic                     麻痹的，瘫痪的

ileus                           肠梗阻

ischemia                    局部缺血

pelvic                         骨盆的

fracture                      破裂，骨折

electrolyte                  电解质

hypokalemia              血钾过少

distension                  膨胀，肿胀

perpetuate                 使永久存在，使延长

atony                          张力缺乏，迟缓

aggravate                   加重

gangrenous                坏疽性的

luminal                        腔的

anaerobe                    厌氧菌

lethal                           致死的

endotoxin                    内毒素