It starts when the smallest motor units with the smallest fibers are activated by your most excitable neurons.

当你最易兴奋的神经元激活具有最小纤维的最小运动单元时，它就开始了。

But when they're in, they are all in -- packing fifty times the force of those smaller fibers.

但是当它们在体内时，它们都在体内——它们的力量是那些较小纤维的 50 倍。

Then, the nets and ropes that are made of the same types of plastic are shredded into small fibers.

然后，将由相同类型的塑料制成的网和绳子撕成细小的纤维。

51.However, if there is more activity in small nerve fibers, then there will be pain. Here is what the gate control theory looks like.

然而，如果小神经纤维更活跃，就会有疼痛。这就是门控理论。

Muscle tissue consists of very small fibers. The nerve fibers separate within a muscle with a terminal branch of the nerve going to each muscle fiber.

肌肉组织由非常小的纤维组成。神经纤维在肌肉内分支，每一个神经纤维终支都进入一根肌纤维。

48.The Gate Control Theory: This theory states that pain is a function of the balance between the information traveling into the spinal cord through large nerve fibers and information traveling into the spinal cord through small nerve fibers .

这个理论认为，疼痛是通过大神经纤维进入脊髓的信息和通过小神经纤维进入脊髓的信息之间的一种功能平衡。