The 2nd order neuron then sends off an axon that crosses over to the opposite side of the medulla, and travels up to the ventral posterior nucleus of the thalamus to synapse with a 3rd order neuron.

然后，第二级神经元发出轴突交叉至对侧延髓，到达丘脑腹后核与第三级神经元突触连接。