Which embryonic germ layer produces the nervous system?

What occurs in this neural pathway at label “3”?   

In ________, one neuron synapses on several postsynaptic neurons.

The pectineus inserts on the _______________ of the femur.

The psoas major is an adductor of the hip.

The gluteus maximus ____________ the hip.

The pectineus inserts on the _______________ of the femur.

The innermost intercostals are innervated by_______________________?

The talus is the largest bone of the foot.

The tibialis posterior is an evertor of the ankle.