Berkely review/literature says that the somatic nervous system can be distinguished from the autonomic nervous system in that it is always excitatory. while the autonomic can be either excitatory or inhibitory.
But the example of a reflex arc in the Berkley Review book given for the patellar tendon, there is a polynaptic reflex arc that causes the hamstring muscle to be inhibitited (so the quads can contract and straighten the knee muscle.
Does it have to do with the fact that here we deal with an interneuron?
Taken from wiki page as well "The sensory input from the quadriceps also activates local interneurons that release the inhibitory neurotransmitter glycine onto motor neurons of antagonist muscles, blocking the innervation of these antagonistic (hamstring) muscles. The relaxation of the opposing muscle facilitates (by not opposing) the extension of the lower leg."
But the example of a reflex arc in the Berkley Review book given for the patellar tendon, there is a polynaptic reflex arc that causes the hamstring muscle to be inhibitited (so the quads can contract and straighten the knee muscle.
Does it have to do with the fact that here we deal with an interneuron?
Taken from wiki page as well "The sensory input from the quadriceps also activates local interneurons that release the inhibitory neurotransmitter glycine onto motor neurons of antagonist muscles, blocking the innervation of these antagonistic (hamstring) muscles. The relaxation of the opposing muscle facilitates (by not opposing) the extension of the lower leg."
