Question: What structure contains the cell bodies of sensory neurons?

Answer: The cell bodies of sensory neurons are found within the dorsal root ganglion.

Question: The filum terminale and the long dorsal and ventral roots that extend caudal to the conus medullaris form what anatomical structure?

Answer: The cauda equina is formed from the filum terminale and the long dorsal and ventral roots

that extend caudal to the conus medullaris.

Question: Identify the location of the cerebrospinal fluid that surrounds the spinal cord.

Answer: The cerebrospinal fluid that surrounds the spinal cord is found in the subarachnoid space,

which lies between the arachnoid mater and the pia mater.

Question: List the three meninges that cover the spinal cord and the spinal nerve roots in order from deep to superficial.

Answer: There are three meningeal layers surrounding the spinal cord and nerve roots. From deep (closest

to the spinal cord) to superficial, these three layers are the pia mater, arachnoid mater, and dura

mater.

Question: A patient with polio—a viral infection of motor neurons—has lost the use of his leg muscles. In what area of his spinal cord would you expect to find the infected motor neurons?

Answer: Since the poliovirus would be located in the somatic motor neurons, we would find it in the

anterior horns of the spinal cord where the cell bodies of these neurons are located.

Question: What is the difference between ascending tracts and descending tracts in the white matter?

Answer: Ascending tracts carry sensory information toward the brain. Descending tracts carry motor

commands into the spinal cord.

Question: Describe, in order from outermost to innermost, the three connective tissue layers surrounding each peripheral nerve.

Answer:

Question: Distinguish between a white ramus and a gray ramus.

Answer: The white and gray rami connect the spinal nerve to a nearby autonomic ganglion. The

white ramus carries preganglionic axons that are myelinated from the nerve to the ganglion.

The gray ramus carries postganglionic unmyelinated axons from the ganglion back to the

spinal nerve.

Question: Injury to which of the nerve plexuses would interfere with the ability to breathe?

Answer: The phrenic nerves that innervate the diaphragm originate in the cervical plexus. Damage to

this plexus or, more specifically, to the phrenic nerves would greatly interfere with the ability to

breathe and possibly result in death by suffocation.

Question: Which nerve plexus may have been damaged if motor activity in the arm and forearm are affected by injury?

Answer: The brachial plexus may have been damaged.