So, the preganglionic fiber releases ACh, and the postganglionic releases norepinephrine.

所以前释放 ACh，后释放去甲肾上腺素。

From there, the postganglionic fibers are super short — just long enough to communicate with their effector.

从那里，后超短——刚好足够长以与它们的效应器交流。

The key here is that, in the sympathetic system, the preganglionic fibers are much shorter than the postganglionic ones.

这里的关键是，在交感系统中，前后短得多。

And at the end of that second, postganglionic neuron, the fiber releases a different neurotransmitter.

在那一秒钟的末尾，后元，会释放不同的递质。

This one's called norepinephrine. And it is always norepinephrine that's released from postganglionic fibers in the sympathetic nervous system.

这个叫做去甲肾上腺素。交感系统后释放的永远是去甲肾上腺素。

Understandably enough, the axon lengths of the neurons before the ganglion are called the preganglionic fibers, and the ones coming out are postganglionic.

可以理解的是，前元的轴突长度被称为前，出来的是后。

So, that acetylcholine crosses the synapse and, if there's enough of it, it can stimulate action potentials in several neurons on the other end — in the postganglionic fibers.

乙酰胆碱穿过突触，如果有足够的乙酰胆碱，它可以刺激另一端的几个元的动作电位——在后中。

But in your parasympathetic system, the postganglionic neurons release ACh at their synapses with the effector organs, too as opposed to in the sympathetic system, where effectors get a dose of norepinephrine instead.

但是在你的副交感系统中，后元在它们与效应器官的突触处释放 ACh，而在交感系统中，效应器官得到一剂去甲肾上腺素。

Those postganglionic neurons then carry the action potential to the effector organs — in this case, let's say your leg muscles, which are going to need an influx of blood if they're going to hustle you out of that house.

后元然后将动作电位传递到效应器官——在这种情况下，方说你的腿部肌肉，如果它们要把你赶出房子，它们需要大量的血液。