First, the ankle reflexes are lost, and soon after the patellar and arm reflexes are lost as well.

最先消失是踝反射，然后是膝反射，最后手臂反射也会消失。

A strike to your patellar tendon triggers an electrical impulse that travels up a sensory neuron to your spine.

击骨肌腱会触发电子脉冲。该脉冲将沿着觉神经元上传到脊椎。

When we tap your, let's say your patellar tendon that causes a stretch in a muscle spindle, this sends a signal back to the sensory neuron, which activates a motor neuron in the spinal cord to cause your knee to kick up.

当击，比方说骨腱，它会导致肌肉纺锤体拉伸，这会向觉神经元发送信号，这会激活脊髓中运动神经元，使膝盖抬起。

If you hit my patellar tendon with a reflex hammer, my leg is going to jerk forward, and it's going to jerk forward a lot faster and a lot more predictably than if I had to think about it myself.

如果用反射锤击打腱，腿就会向前猛拉，而且它会比自己考虑时更快、更可预测地向前猛拉。