Review Questions

Directions: Each of the numbered items in this section is followed by answers. Select the ONE lettered
answer that is CORRECT.

1. The following statements concern the spinal cord: (a) Theanteriorandposteriorgraycolumnsonthe

two sides are united by a white commissure. (b) The terminal ventricle ls the expanded lower

end of the fourth ventricle.

(c) Thelargernervecellbodiesintheanteriorgray

horns give rise to a efferent nerve fibers In the

anterior roots.

4. (d)  The substantia gelaUnosa groups of cells are

locatedatthebaseofeachposteriorgraycolumn.

5. (e)  The nucleus dorsalis (Clarke column) is a group of nerve cells found in the posterior gray
column and restricted to the lumbar segments of the cord.

2. The following statements concern the white col-

umns of the spinal cord:

1. (a)  The posterior sptnocerebellar tract ls situated

in the posterior white column.

2. (b)  The anterior splnothalamlc tract ls found In the

anterior white column.

3. (c)  The lateral splnothalamlc tract is found in the

anterior white column.

4. (d)  The fasciculus gracllls Is found in the lateral

white column.

5. (e)  The rubrospinal tract is found in the anterior

white column.

3. The following statements concern the spinal cord:

 1. (a)  The spinal cord has a cervical enlargement for the brachial plexus.
2. (b)  The spinal cord possesses spinal nerves that are attached to the cord by anterior and pos-
terior raml.
3. (c)  ln the adult, the spinal cord usually ends infe- riorly at the lower border of the fourth lumbar
vertebra.
4. (d)  The llgamentum dentlculatum anchors the spi- nal cord to the pedicles of the vertebra along
each side.
5. (e)  The central canal does not communicate with the fourth ventricle of the brain.

absence of their Influence on the lower motor neurons are responsible for the increased tone and tremor.

13. (a) Intention tremor occurs in cerebellar disease. (b) Athetosls occurs in lesions of the corpus strl-
atum. (c) Chorea occurs in lesions of the corpus striatum. (d) Dystonia occurs in disease of the len- tiform
nucleus. (e) Hemiballismus occurs in disease of the opposite subthalamic nucleus.

Directions: Matching Questions. Questions 4 through 9 apply to the following figure. Match the numbers
listed on the left with the appropriate lettered structure listed on the right. Each lettered option may be
selected once, more than once, or not at all.

4. Number 1 5. Number2 6. Number3 7. Number4 8. Numbers 9. Number6

(a) Nucleus proprius

(b) Preganglionic sympathetic outflow (c) Nucleus dorsalis
(d) Substantia gelatinosa
(e) None of the above

Directions: Each of the numbered Items in this section is followed by answers. Select the ONE lettered
answer that is CORRECT.

10.

The following statements concern the cell of origin of the tracts listed below:

1. (a)  The fasciculus cuneatus arises from cells in the

substantia gelatinosa.

2. (b)  The anterior spinothalamic arises from cells in

the posterior root ganglion.

3. (c)  The fasciculus gracilis arises from cells in the

nucleus dorsalis (Clarke column).

4. (d)  The anterior sptnocerebellar arises from cells

In the posterior root ganglion.

 5. (e)  The lateral spinothalamlc arises from cells In

the substantla gelatlnosa.

3
11. The following statements concern the courses taken by the tracts listed below:
 1. (a)  The fasciculus gracilis does not cross to the

opposite side of the neural axis.

2. (b)  The spinotectal tract does not cross to the

opposite side of the spinal cord.

3. (c)  The lateral spinothalamic tract does not cross

to the opposite side of the spinal cord.

4. (d)  The posterior spinocerebellar tract crosses to

the opposite side of the neural axis.

5. (e)  The anterior spinothalamic tract immediately crosses to the opposite side of the spinal cord.
12. The following statements concern the nucleus of

termination of the tracts listed below:

1. (a)  The posterior white column tracts terminate in

the Inferior colllculus.

2. (b)  The spinoreticular tract terminates on the neu-

rons of the hippocampus.

3. (c)  The spinotectal tract terminates in the inferior

colliculus.

4. (d)  The anterior spinothalamlc tract terminates in the

ventral posterolateral nucleus of the thalamus.

5. (e)  The anterior spinocerebellar tract terminates in

the dentate nucleus of the cerebellum.

13. The following statements relate sensations with the

appropriate nervous pathways:

(d) Many of the tracts conducting the initial, sharp, pricking pain terminate in the dorsal anterolat- eral nucleus of
the thalamus.

(e) The slow-conducting C-type fibers are responsi- ble for prolonged, burning pain.
16. The following statements concern the corticospinal tracts:

(a)

(b) (c)

(d)

(e)

Two-point tactile discrimination travels in the lateral splnothalamic tract.

Pain travels in the anterior spinothalamic tract. Unconscious muscle joint sense travels in the anterior
spinocerebellar tract.

Pressure travels in the posterior spinothalamic tract.

Vibration travels in the posterior spinocerebel- lar tract.

17. The following statements concern the course taken by the tracts listed below:
(a) The rubrospinal tract crosses the midline of the

neuroaxis in the medulla oblongata.

(b) The tectosplnal tract (most of the nerve fibers) crosses the midline in the posterior commis-

sure.
(c) The vestibulospinal tract crosses the midline in

the midbrain.
(d) The lateral corticospinal tract crosses the mid-

line in the medulla oblongata.

(e) The anterior corticospinal tract crosses the

midline in the midbrain.

18. The following statements concern the nerve cells of

14. The following statements concern the gating theory of pain:

1. (a)  Stimulation of small non-pain-conducting fibers in a peripheral nerve may reduce pain
sensitiv- ity.
2. (b)  Massage applied to the skin over a painful joint may reduce pain sensitivity.
3. (c)  Stimulation of oA- and C-type fibers in a spinal nerve posterior root may decrease pain sensi-
tivity.
4. (d)  Degeneration of large non-pain-conducting fibers in a peripheral nerve decreases pain sen-
sitivity.
5. (e)  Inhibition of pain conduction in the spinal cord does not involve connector neurons.
15. The following statements concern the reception of pain:
1. (a)  Serotonin is not a transmitter substance in the analgesic system.
2. (b)  Substance P is thought to be the neurotransmit- ter at the synapses where the first-order
neuron terminates on the cells in the posterior gray column of the spinal cord.
3. (c)  Enkephalins and endorphins may stimulate substance P release in the posterior gray col- umn
of the spinal cord.
19.

origin for the tracts listed below:

1. (a)  The vestibulospinal tract originates from cells

of the medial vestibular nucleus situated in the

pons.

2. (b)  The tectospinal tract originates from cells In

the inferior colliculus.

3. (c)  The lateral cortlcosplnal tract originates from

cells in area 4 of the cerebral cortex.

4. (d)  The rubrospinal tract originates from cells in

the reticular nucleus.

5. (e)  The reticulospinal tract originates from cells in

the reticular formation that is confined to the

midbrain.

The following statements concern muscle move- ment:

1. (a)  Muscular fasciculation is seen only with rapid

destruction of lower motor neurons.

2. (b)  Muscle spindle afferent nerve fibers send infor-

mation only to the spinal cord.

3. (c)  In Parkinson disease, dopamine-secreting neu-

rons that originate In the vestibular nucleus

degenerate.

4. (d)  Brain neuronal activity preceding a voluntary

movement is limited to the precentral gyrus

 (area 4).

5. (e)  Hyperactive ankle-jerk reflexes and ankle clo-

nus indicate release of lower motor neuron supraspinal inhibition.

(a) (b) (c) (d)

(e)

They occupy the posterior limb of the internal capsule.

They are mainly responsible for controlling the voluntary movements in proximal limb muscles. They arise as axons
of the pyramidal cells In the fourth layer of the cerebral cortex.

Those that control the movements of the upper limb originate in the precentral gyrus on the medial side of the
cerebral hemisphere.
Those that are concerned with the movements of the lower limb are located in the medial area of the middle three
fifths of the basis peduncull.

Review Questions 181

182 CHAPTER 4 Spinal Cord and Ascending, Descending, end lnten1egmental Tracts
 20. After a hemorrhage Into the left Internal capsule In a right-handed person, the following sign or symptom
might be present:
(a) Left homonymous hemianopia

(b) Right astereognosis

(c) Left hemiplegia
(d) Nonnal speech
(e) Left-sided positive Babinski response

21. A patient with a traumatic lesion of the left half of the spinal cord at the level of the eighth cervical
segment might present the following sign(s) and symptom(s):
1. (a)  Loss of pain and temperat\ll"e sensations on the left side below the level of the lesion
2. (b)  Loss of position sense of the right leg
3. (c)  Right hemiplegia
4. (d)  Left positive Babinski sign
5. (e)  Right-sided lower motor paralysis in the seg-

ment of the lesion and muscular atrophy

Directions: Each of the numbered items in this section is followed by answers. Select the ONE lettered answer that
is BEST in each case.

22. Which of the signs and symptoms listed below Indi- cate a cerebellar lesion?
(a) Cogwheel rigidity
(b) Hemiballismus

(c) Chorea
(d) Intention tremor (e) Athetosis

23. Which of the following regions of white matter would not contain cortlcosplnal fibers?
(a) Pyramidofmedullaoblongata
(b) Lateral white column of the spinal cord

(c) Cerebralpeduncleofthemidbrain (d) Anterior limb of the internal capsule (e) Coronaradlata

Directions: Each case history is followed by questions. Read the case history, then select the ONE BEST let- tered
answer.

A 59-year-old woman was experiencing pain In the back and showed evidence of loss of pain and temperature
sensations down the back of her left leg. Three years previously, she underwent a radical mastectomy fol- lowed by
radiation and chemotherapy for advanced carcinoma of her right breast.

Examination showed that she was experiencing pain over the lower part of the back, with loss of the skin
sensations of pain and temperature down the back of her left leg in the area of the Sl-S3 dermatomes. No other
neurologic deficits were identified. Radiographic examination of the vertebral column showed evidence of
metastases in the bodies of the 9th and 10th thoracic vertebrae. An MRI revealed an extension of one of the
metastases Into the vertebral canal, with slight Indenta- tion of the spinal cord on the right side.

24. The pain in the back could be explained in this patient by the following facts except:

1. (a)  Osteoarthritis of the joints of the vertebral

 column

2. (b)  Metastases In the bodies of the 9th and 10th

thoracic vertebrae

3. (c)  Tumor pressure on the spinal nerve posterior

roots

4. (d)  A prolapsed intervertebral disc pressing on the

spinal nerves

5. (e)  Spasm of the postvertebral muscles following

tumor pressure on the posterior white columns

of the spinal cord

25. Loss of pain and temperature sensations down the

back of the patient's left leg in the area of the Sl-S3 dermatomes could be explained by the following factual
statements except

1. (a)  Lateral splnothalamic tracts In the spinal cord

conduct the sensations of pain.

2. (b)  Lateralspinothalamlctractsarelaminated,with

the sacral segments of the body located most

laterally.

3. (c)  The sacral segments of the tracts are the

most exposed to external cord pressure from a

metastasizing tumor.

4. (d)  Loss of temperature sensations in the leg could

be explained by tumor pressure on the anterior

spinothalamic tract.

26. The severe intractable pain In the back in this

patient could be treated by the following methods

ezcept:

1. (a)  Prescription of sallcylates In large doses

2. (b)  Intramuscular injection of morphine or even the direct Injection of the opiate into the spinal cord
3. (c)  Posterior rhlzotomy
4. (d)  Cordotomy
5. (e)  Injectionofopiatesintothesubarachnoidspace

1.

Answers and Explanations to Review Questions

C is correct. The larger nerve cell bodies In the ante- rior gray horns give rise to a efferent nerve fibers In the
anterior roots. A. The anterior and posterior gray columns on the two sides of the spinal cord are united by a gray
commissure formed of gray matter. B. The terminal ventricle Is the expanded lower end of the central canal. D. The
substantla gelatinosa group of cells is located at the apex of each posterior gray col- umn throughout the length of
the spinal cord. E. The

nucleus dorsalis (Clarke column) is a group of nerve cells found In the posterior gray column and extend-
ingfromtheeighthcervicalsegmentofthecordtothe third or fourth lwnbar segment.

2. B Is correct. In the spinal cord, the anterior spi- nothalamlc tract is found in the anterior white column. A. The
posterior splnocerebellar tract is situated in the lateral white column. C. The lateral spinothalamic tract is found in
the lateral white
column. D. The fasciculus gracilis is found in the posterior white column. E. The rubrospinal tract is found in the
lateral white column.

3. A is correct. The spinal cord has a cervical enlarge- ment for the brachial plexus (Fig. 4-5). B. The spinal
cord possesses spinal nerves that are attached to the cord by anterior and posterior nerve roots. C. In the
adult, the spinal cord usually ends inferi- orly at the lower border of the first lumbar vertebra. D. The
ligamentum denticulatum anchors the spi- nal cord to the dura mater along each side. E. The central canal,
which contains cerebrospinal fluid, communicates with the fourth ventricle of the brain.
4. D Is correct.
5. A is correct.
6. C Is correct.
7. B is correct.
8. E is correct. The structure is the anterior gray horn.
9. E is correct. The structure is the gray commissure.
10. E is correct. In the spinal cord, the lateral spi- nothalamlc tract arises from cells in the sub- stantia
gelatinosa. A. The fasciculus cuneatus arises from cells in the posterior root ganglion. B. The anterior
spinal thalamic arises from cells in the substantia gelatinosa. C. The fasciculus gracilis arises from cells In
the posterior root ganglion. D. The anterior spinocerebellar arises from cells in Clarke column.
11. A is correct. The fasciculus gracilis does not cross to the opposite side of the neural axis. B. The spinotectal
tract crosses to the opposite side of the spinal cord. C. The lateral spinothalamic tract crosses to the
opposite side of the spinal cord. D. The posterior spinocerebellar tract does not cross to the opposite side of
the spinal cord. E. The anterior spinothalamic tract crosses very obliquely to the opposite side of the spinal
cord.
12. D is correct. The anterior spinothalamic tract ter- minates in the ventral posterolateral nucleus of the
thalamus. A. The posterior white column tracts terminate in the nucleus gracilis and cuneatus. B. The
splnoretlcular tract terminates on the neu- rons of the reticular formation in the medulla, pons, and
midbrain. C. The spinotectal tract terminates in the superior colliculus. E. The anterior spinoc- erebellar
tract terminates in the cerebellar cortex.
13. C is correct. Unconscious muscle joint sense trav- els in the anterior spinocerebellar tract. A. Two- point
tactile discrimination travels in the fasciculus cuneatus. B. Pain travels in the lateral spinotha- lamic tract.
D. Pressure travels In the anterior spinothalamic tract. E. Vibration travels in the fas- ciculus gracilis.
14. B is correct concerning the gating theory of pain. Massage applied to the skin over a painful joint may
reduce pain sensitivity. A. Stimulation of large non- pain-conducting fibers in a peripheral nerve may
reduce pain sensitivity. C. Stimulation of ~ A- and C-type fibers in a spinal nerve posterior root may
increase pain sensitivity. D. Degeneration of large non-pain-conducting fibers in a peripheral nerve

15.

increases pain sensitivity. E. Inhibition of pain con- duction in the spinal cord could be brought about by means of
connector neurons.
E is correct. The slow-conducting C-type fibers are responsible for prolonged, burning pain. A. Sero- tonin is a
transmitter substance in the analgesic system. B. Substance Pis a peptide and is thought to be the neurotransmitter
at the synapses where the first-order neuron terminates on the cells in the posterior gray column of the spinal cord.
C. Enkephalins and endorphins may inhibit the release of substance P In the posterior gray column of the spinal
cord. D. Many of the tracts conducting the initial, sharp, pricking pain terminate in the ven- tral posterolateral
nucleus of the thalamus.

A is correct. The corticospinal tracts occupy the posterior limb of the internal capsule (Fig. 4-11). B. The
corticospinal tracts are mainly responsible for controlllng the voluntary movements in the distal muscles of the
limbs. C. They arise as axons of the pyramidal cells in the fifth layer of the cere- bral cortex. D. Those that control
the movements of the upper limb originate in the precentral gyrus on the lateral side of the cerebral hemisphere. E.
Those that are concerned with the movements of the lower limb are located in the lateral area of the middle three
fifths of the basis pedunculi.

D is correct. The lateral corticospinal tract crosses the midline in the medulla oblongata (Fig. 4-21). A. The
rubrospinal tract crosses the midline of the neuroaxis in the midbrain. B. The tectospinal tract (most of the nerve
fibers) crosses the midline in the mldbraln. C. The vestibulosplnal tract does not cross the midline and descends
through the medulla oblongata and spinal cord in the anterior white column (Figs. 4-20 and 4-25). E. The anterior
cortico- spinal tract crosses the midline in the spinal cord. C is correct. The lateral cortlcosplnal tract origi- nates
from cells in area 4 of the cerebral cortex. A. The vestlbulosplnal tract originates from cells of the lateral vestibular
nucleus situated in the pons. B. The tectospinal tract originates from cells in the superior colliculus. D. The
rubrospinal tract originates from cells in the red nucleus. E. The reticulospinal tract originates from cells in the retic-
ular formation in the midbrain, pons, and medulla oblongata.

Eis correct. Hyperactive ankle-jerk reflexes and ankle clonus Indicate lower motor neuron release from supraspinal
inhibition. A. Muscular fasciculation is seen only with slow destruction of the lower motor neurons. B. Muscle
spindle afferent nerve fibers send information to the brain as well as to the spinal cord. C. In Parkinson disease,
dopamine-secreting neurons decrease in the substantia nigra D. Brain neuronal activity preceding a voluntary
movement is not lim- ited to the precentral gyrus (area 4).

B is correct. Right astereognosis. A. Right homon- ymous hemianopia is seen. C. Right hemiplegia is present. D.
Aphasia is present. E. A right-sided pos- itive Babinski response is seen.

16.

17.

18.

19.

20.

Answers and Explanations to Review Questions 183

184 CHAPTER 4 Spinal Cord and Ascending, Descending, and lntersegmental Tracts
21. Dis correct. Left positive Babinski sign is present. A. Pain and temperature sensations are lost on the right side
below the level of the lesion. B. Position sense of the left leg is lost. C. Left hemiplegia is present. E. Left-sided
lower motor paralysis is seen in the segment of the lesion and muscular atrophy.

22. D is correct. Intention tremor is present. A. Cog- wheel rigidity occurs in Parkinson disease when the muscle
resistance is overcome as a series of jerks. B. Hemiballismus is a rare form of involun- tary movement confined to
one side of the body; it occurs in disease of the subthalamic nuclei. C. Chorea consists of a series of continuous,
rapid, involuntary, jerky, coarse, purposeless movements, which may take place during sleep; it occurs with lesions
of the corpus striatum. E. Athetosis consists

of continuous, slow, involuntary, dysrhythmic move- ments that are always the same in the same individ- ual, and
they disappear during sleep; lt occurs with lesions of the corpus striatum.

23. D ls correct. The anterior limb of the Internal cap- sule does not contain corticospinal fibers.

24. E is correct. Spasm of the postvertebral muscles would not be produced by pressure on the poste- rior white
columns of the spinal cord.

25. Dlscorrect.Thesensationoftemperaturetravelsin the lateral spinothalamic tract along with the pain impulses.

26. A is correct. Salicylates, such as aspirin, sodium salicylate, and diflunisal, are used clinically only for the relief
of mild to moderate pain, as found in patients suffering from headache and dysmen- orrhea.