This hypoxia also causes the parasympathetic nerve fibers to die off.

这种缺氧还会导致副交感神经纤维死亡。

These parasympathetic neurons make the rectum contract and the internal anal sphincter relax.

这些副交感神经元可以使直肠收缩，并使肛门内括约肌松弛。

" Point" is erection and it's caused by " P, " or parasympathetic fibers.

“Point”代表勃起，它是由“P”副交感（parasympathetic）神经纤维引起的。

In both cases, the parasympathetic nerve fibers in the cavernosal spaces release acetylcholine from their nerve endings.

在这两种情况下，副交感神经纤维在海绵体间隙通过神经末梢释放乙酰胆碱。

And, foils being what they are, the reverse is of course true for the parasympathetic system.

而且，副交感神经系统的情况正好和陪衬是相反的。

If the heat generated is intense enough, the body's parasympathetic nervous system is triggered, which creates a relaxation response.

如果产生的热量足够强烈，身体的副交感神经系统就会被触发，从而产生放松反应。

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。

We have parasympathetic nervous system and our sympathetic nervous system.

我们有副交感神经系统和交感神经系统。

But the nerve fibers of your parasympathetic system begin both above and below where the sympathetic ones do.

但是副交感神经系统的神经纤维是从交感神经的上方和下方开始的。

The parasympathetic is coming in to just tamp down the threat response a little bit.

副交感神经的作用只是稍微抑制威胁反应。