10.18 Wiring Principles - Sensory and Motor Flashcards
where are the primary afferent cell bodies? on what side
in the dorsal root ganglion on the ipsilateral side
where do the processes from the primary afferents go?
the dorsal root of the spinal cord
the shortest path to the cerebral cortex must be ______ neurons long.
three
when does the primary afferent for sensation and proprioception meet the second order neuron?
in the brainstem
when does the primary afferent for pain and temperature meet the second order neuron?
in the spinal cord
in addition to ACh, primary motor neurons release
trophic factors
can cause atrophy if not there!
explain the inputs and outputs of the corticospinal tract:
inputs from the UMN in the primary motor cortex to LMNs in the spinal cord
what are the two inputs to the LMNs?
- from sensory fibers of muscle length and stretch
2. input from the UMNs
what suppresses the deep tendon reflex?
upper motor neurons
Upper motor neurons directly activate the _____ and suppress the ______
lower motor neurons
deep tendon reflex
what physical exam findings would you find with LMN damage?
weakness
hypo-reflexia
negative Babinski
what physical exam findings would you find with UMN damage?
weakness
hyper-reflexia
positive Babinski
what would you see with problems of the basal ganglia?
slowness and rigidity, motor control
NOT weakness
lesions to the basal ganglia cause motor control problems ____________ to the body. why?
contralateral
they connect to the ipsilateral cerebral cortex
lesions to the cerebellum cause problems with motor control ________ to the body
ipsilaterally
because info from the motor cortex crosses before getting to the cerebellum
