D170 W15
Neural Pathways
Williams
This set of notes covers information from several different chapters. Think of it as “tying a bow” on the
entirety of our nervous system lectures. Pages: (pages 363 – 367, 396 – 397, 410 – 419, 444 – 446)
Chapter 12:
What structures compose the PNS? What structures compose the CNS?
Where do the CNS and PNS structurally link together?
What is a reflex arc? Describe the steps.
Compare and contrast monosynaptic and polysynaptic reflexes and give examples of each.
Describe how interneurons can be connected in the neuronal
circuits listed below. Give an example of each.
Diverging circuit –
Converging circuit –
Reverberating circuit –
D170 W15
Neural Pathways
Williams
Serial processing –
Parallel processing –
Explain how the PNS and CNS are integrated through spinal and cortical pathways. What is the
difference between a spinal pathway and a cortical pathway?
Chapter 13 Skip to page 396…
Describe the function and location of the following types of fibers found in the white matter of the
cerebrum.
Commissural fibers –
Association fibers –
Projection fibers –
Skip to page 410…
How is white matter organized in the spinal cord?
How is the gray matter organized in the spinal cord?
D170 W15
Neural Pathways
Williams
What are ascending and descending pathways?
What are four important summary features of the ascending and descending pathways?
What are ascending and descending spinal tracts?
What is the order of neurons and connections in an ascending pathway? In a descending pathway?
What does it mean for a tract or pathway to “decussate?”
How many neurons are typically found in ascending pathways?
Fill out the following table to summarize the main features of the main ascending pathways.
Location(s) in
cross-section
of spinal cord
/ brain
Spinocerebellar
pathway
Dorsal columnmedial lemniscal
pathway
Function
Origin
Termination
D170 W15
Neural Pathways
Spinothalamic
pathway
What are upper and lower motor neurons in descending pathways?
Williams
D170 W15
Neural Pathways
Williams
Fill out the following table to summarize the main features of the main descending pathways.
Location(s) in
cross-section
of spinal cord
/ brain
Direct pathways
(pyramidal tracts)
Indirect pathways
(extrapyramidal
tracts)
Function
Origin
Termination
D170 W15
Chapter 14: Skip to page 444…
Neural Pathways
Williams
D170 W15
Neural Pathways
Williams
Draw how a sensory pathway and a motor pathway may travel through spinal nerves to reach the
gray matter of the spinal cord. (Figure 14.7). What structures do motor axons travel through?
Sensory axons? What are the locations of sensory neuron cell bodies? Of motor neuron cell bodies?