So far what we've looked at is the lower motor neurons and the local circuit neurons which we discussed how they mediate actual muscular movement. The higher brain centers that control movement send signals via the upper motor neurons to these lower motor neurons/local circuit neurons.
Descending tracts : Pyramidal = corticospinal ( control body muscles; anterior for proximal and lateral for distal muscles, and corticobulbar (control muscles of the face)
Extra-pyramidal = vestibulospinal (balance) and reticulospinal (consciousness and posture)
RAW VIDEO TRANSCRIPT: i didnt manage to get around to making notes
So here we have encircled there. The descending systems. And the relationship between the upper motor neuron with the lower motor neuron is not one where the upper motor neuron necessarily micromanages the function of the lower motor neuron. UM, because of course, as we said, the lower motor neuron is the one that is actually the final path to movement. According to Charles Sherrington. So the relationship between the upper motor neuron and the lower motor neuron is more concerned with. Communication of intention of movement. As well as plans of that movement, so upper motor neurons communicate intention of movement. They initiate movement, they are involved in planning of movement. And they passed that information down to local uh local motor, lower motor neurons and local circuit neurons. Sorry. Upper motor neurons involve both the motor cortex and the cerebrum. Which is more concerned with the skilled movements? UM and movements of the distal parts of the body of the limbs. But Apple motor neurons or descending systems are also found in brain stem centers. And these are more concerned with the control of balance and posture. As well as stereotype movements or rhythmic movement. All right. So so that's about it. On the overview of the motor system, maybe also we shouldn't forget that the upper motor neurons in the descending systems mainly innovate the local circuit neuron. That's a very important point. They mainly innovate the local. The neurons, which is the the inter neurons that we find in the spinal cord. Rather than going directly onto the lower motor neurons. But we do have just a little bit of direct innovation of the lower Motor neurons by the upper motor neuron.