Once the rectum is filled and stretched, signals travel to parasympathetic neurons in the spinal cord, initiating the defecation reflex.

当直肠被粪便填满并受到牵拉时，就会向脊髓内的副交感神经元发出信号，启动排便反射。

And here, special nerve receptors measure pressure, and when enough waste pushes against the rectum walls, it triggers the defecation reflex.

这里，特殊的神经感受器测量压力，当足够多的废物冲击直肠壁时，它会触发排便反射。

Here, special nerve receptors measure pressure, and when enough waste pushes against the rectum walls, it triggers the defecation reflex.

在这里， 特殊的神经感受器测量压力，当足够多的废物推到直肠壁时，它会触发排便反射。