Chapter 13
Spinal Cord, Spinal Nerves and Somatic Reflexes

1. Understand all of the key terms (selected vocabulary on page 511).

2. Know the functions of the spinal cord.
3. Know the structure of the spinal cord.
4. Know where the spinal cord begins and where it ends. Know why the spinal cord does not fill up the vertebral canal.
5. Understand the relationship between spinal nerves, sensory and motor signals and the spinal cord.
6. Know the organs that make up the CNS and PNS.
7. Know how many spinal nerves they are and know how many arise from each segment of the spinal cord.
8. Know where the spinal cord enlargements are and why they exist.
9. Know where the cauda equinae are located.
10. Know what meninges are, what their function is, and where they are located. Know what the terms epidural, subarachnoid and subdural mean.
11. Know what Spina Bifida is, what the effects are and how the risk can be reduced.
12. Know the cross-sectional anatomy of the spinal cord. Know the location of the gray and white matter. Know what parts of a neuron give the gray and white matter their color.
13. Know what types of nerve fibers carry signals to or from the dorsal and ventral horns and roots.
14. Understand what ‘tracts’ are.
15. Know the relationship between the direction a signal travels (up or down) and the type of information being relayed (sensory or motor).
16. Understand what the terms decussation, contralateral and ipsilateral mean.
17. Know the Dorsal Column Ascending Pathway. Know the types of sensory information carried via this pathway and know where the signal originates and where it ends. Know the effect that decussation has on this tract. UNDERSTAND what the effect would be if there was damage to this pathway on one side of the brain.
18. Know the Spinothalamic Pathway. Know the types of sensory information carried via this pathway and know where the signal originates and where it ends. Know the effect that decussation has on this tract. UNDERSTAND what the effect would be if there was damage to this pathway on one side of the brain.
19. Know the Corticospinal Tract. Know the types of information carried via this pathway and know where the signal originates and where it ends. Know the effect that decussation has on this tract. UNDERSTAND what the effect would be if there was damage to this pathway on one side of the brain.
20. Know what upper and lower motor neurons are.
21. Based on the names of all of the tracts, know the direction (up or down) that each tract carries its signals.
22. Understand the entire section on Poliomyelitis and ALS.
23. Know what a nerve is and know its anatomy. Know where the epineurium, perineurium and endoneurium are located.
24. Know what ganglia are.
25. Know where the dorsal root ganglia are located and know the type of signal the neurons in these ganglia transmit.
26. Know what a mixed nerve is.
27. Know what the proximal and distal branches are.
28. Know what the dorsal ramus, ventral ramus and meningeal branches innervate.
29. Understand the section on Shingles.
30. Understand what a nerve plexus is and why they are important.
31. Know the names of the 5 plexuses and know which spinal nerves are included in each. Know the general areas that each plexus supplies.
32. Understand what the dermatomes mean.
33. Understand the nature of somatic reflexes and know the 5 components of a somatic reflex arc.
34. Know what a muscle spindle is and what it detects.
35. Know how the stretch reflex works and what purpose it serves.
36. Know what the tendon reflex is and why it is used by physicians.
37. Know what reciprocal inhibition is and why it is important.
38. Know the purposes of the flexor withdrawal and crossed extensor reflexes.
39. Understand the entire section on spinal cord trauma.