160398066-quiz-2

@1. The ability to recognize an unseen familiar object placed in the hand depends on

the integrity of which pathway?

(A) Spinospinal tract

(B) Dorsal column

(C) Dorsal spinocerebellar tract

(D) Spino-olivary tract

B. The ability to recognize the form and texture of an unseen familiar object is called

stereognosis. This is an important function of the dorsal column–medial lemniscus

system.

@2. The spinal tract involved with the control of trunk muscles is the

(A) cuneocerebellar

(B) vestibulospinal

(C) ventral corticospinal

(D) lateral corticospinal

2–C. The ventral corticospinal tract is concerned with the control of axial muscles,

including the muscles of the trunk and head.

@3. The sensation produced by a wisp of cotton on one’s fingertip is mediated by the

(A) cuneocerebellar tract

(B) dorsal column–medial lemniscus pathway

(C) ventral spinocerebellar tract

(d) ventral spinothalamic tract

3–d. The ventral spinothalamic tract is concerned with light touch, the sensation

produced by stroking glabrous skin with a wisp of cotton.

@4. First-order neurons of the ventral spinocerebellar tract

(A) are found in dorsal root ganglia at all levels

(B) provide the afferent limb for muscle

stretch reflexes

(C) project axons into the medial root entry

zone

(D) give rise to the fasciculus cuneatus

B. First-order neurons of the ventral spinocerebellar tract provide the afferent limb for

muscle stretch reflexes. They are found in the dorsal root ganglia from L1 to S2 and

synapse on spinal border cell. First-order neurons of the ventral spinothalamic and

dorsal spinocerebellar tracts project axons into the medial root entry zone; first-order

neurons of the dorsal column–medial lemniscus pathway give rise to the fasciculus

gracilis and cuneatus; and first-order neurons of the lateral spinothalamic tract project

axons via the dorsolateral tract of Lissauer.

@5. Acute-stage upper motor neuron lesions result in

(A) hypertonia

(B) spastic paresis

(C) flaccid paralysis

(D) extensor toe response

Ans C. Acute-stage upper motor neuron lesions result in transient spinal shock, which

includes flaccid paralysis, areflexia, and hypotonia. Chronic-stage lesions result in

spastic paresis, hypertonia, reduction or loss of superficial abdominal and

cremasteric reflexes and extensor toe response, and clonus.

@6. Which of the following tracts Contains axons from the giant cells of Deiters

. (A) Cuneocerebellar tract

. (B) Vestibulospinal tract

. (C) Dorsal spinocerebellar tract

. (D) Lissauer tract

. Ans B The vestibulospinal tract arises from the giant cells of Deiters found in

the ipsilateral lateral vestibular nucleus of the pons. The vestibulospinal tract

facilitates extensor muscle tone.

@7. Which of the following tracts Is the upper extremity equivalent of a tract

that arises from the cells of Clarke column


. (B) Cuneate fasciculus


. (D) Lateral corticospinal tract

. 7–A. The cuneocerebellar tract is the upper extremity equivalent of the dorsal

spinocerebellar tract, which arises from the cells of the Clarke column. The

cuneocerebellar tract arises from cells of the accessory cuneate nucleus, a

homolog of the nucleus of Clarke.

@8. Which of the following tracts Conveys nociceptive input from the con-

tralateral side of the body


. (B) Lateral spinothalamic tract



.

. Ans B The lateral spinothalamic tract conveys nociceptive input from the

contralateral side of the body.

. @9. Which of the following tracts Contains axons from the giant cells of Betz

(A) Cuneocerebellar tract




. 9–D. The lateral corticospinal tract contains axons from the giant cells of Betz.

The giant pyramidal cells of Betz are found in the precentral gyrus and in the

anterior paracentral lobule

@10. Which of the following tracts Contains ipsilateral pain fibers that have their

second-order neurons in the dorsal horn


. (B Lissauer tract


. (D) Vestibulospinal tract

10–b. The dorsolateral tract of Lissauer contains ipsilateral pain fibers that have their

second- order neurons in the dorsal horn.

@11. Which of the following tracts Projects to the cerebellum via the inferior

cerebellar peduncle





Ans C The dorsal spinocerebellar tract projects unconscious proprioceptive

information (muscle spindles and GTOs) to the cerebellum via the inferior cerebellar

peduncle.

12. Which of the following tracts Mediates pain and temperature sensation

a) Dorsal spinocerebellar tract

b) Lateral corticospinal tract

c) Lateral spinothalamic tract

d) Lissauer tract

Ans C

The lateral spinothalamic tract lies between the ventral spinocerebellar tract and the

ventral horn. It mediates pain and temperature sensation.

@13. Cells of origin are found in the precentral gyrus





.

. Ans D The lateral corticospinal tract has its cells of origin in the premotor,

motor, and sensory cortices. The precentral gyrus and the anterior paracentral

lobule are motor cortices and contain the motor homunculus. The lateral

corticospinal gives rise to one-third of the fibers of the corticospinal

(pyramidal) tract.

@ Which of the following tracts Mediates two-point tactile discrimination from the

hand

. (A) Lissauer tract




Ans B The fasciculus cuneatus mediates two-point tactile discrimination from the

hand.

@15. Which of the following tracts Myelination is not fully achieved until the end

of the second year





Ans D The corticospinal (pyramidal) tracts are not fully myelinated until the end of

the second year. For this reason, the Babinski sign may be elicited in young children.

@16. Which of the following tracts Transection results in spasticity





Ans d Transection of the lateral corticospinal tract results in spastic paresis

(exaggerated MSRs and clonus).

@17. Which of the following tracts Plays a role in regulating extensor tone




. D) Vestibulospinal tract

17–D. The vestibulospinal (lateral) tract, found ventral to the ventral horn, plays a

role in regulating extensor tone.

@18. Which of the following tracts Transmits vibration sensation from the ankle



. (C) fasciculus gracilis


18–C. The fasciculus gracilis transmits vibratory sensation (pallesthesia) from the

lower extremities.

@1. Which of the following reflexes is monosy-

naptic?

(A) Achilles reflex

(B) Babinski reflex

(C) Corneal reflex

(D) Extensor plantar reflex

1–A. The Achilles reflex, or ankle jerk reflex, is a myotatic monosynaptic reflex that

is mediated by cord segment S1.

@2. The spinal cord of a newborn baby terminates at

(A) VL1 (B) VL3 (C) VS1 (D) VS3

2–B. In the newborn, the spinal cord ends at the level of the third lumbar vertebra

(VL3). In the adult, the spinal cord ends at the lower border of the first lumbar

vertebra (VL1), and the dural cul-de-sac ends at the level of the second sacral vertebra

(VS2). The pia mater is the innermost meningeal layer of the spinal cord; spinal cord,

pia mater, arachnoid, dura mater, ligamenta flava, periosteum.

@3. Which spinal nerve rami contain unmyelinated postganglionic sympathetic

nerve fibers?

(A) White communicating (B) Dorsal primary

(C) Gray communicating (D) Ventral primary

3–D. Gray communicating rami contain unmyelinated preganglionic sympathetic

fibers, where- as white communicating rami contain myelinated preganglionic

sympathetic fibers and myelinated GVA fibers. The meningeal ramus innervates the

meninges and vertebral column; the dorsal primary ramus innervates the skin and

muscles of the back; and the ventral primary ramus innervates the ventral lateral

muscles and skin of the trunk, extremities, and visceral organs.

@4. The efferent limb of a myotatic reflex includes a

(A) ventral horn motor neuron

(B) muscle spindle

(C) dorsal root ganglion neuron

(D) lateral horn visceromotor nucleus

4–A. The myotatic reflex is a monosynaptic and ipsilateral MSR (incorrectly called a

deep tendon reflex). The efferent limb consists of the axon of a ventral horn alpha

motor neuron that innervates striated muscle fibers (effector); the afferent limb

consists of a muscle spindle (receptor) and an Ia fiber (axon) of a dorsal root ganglion

neuron. The quadriceps (patellar) and triceps surae (ankle) MSRs are myotatic

reflexes.

@5. Which of the following spinal cord levels Contains preganglionic

parasympathetic neurons

(A) Cervical cord (

B) Upper thoracic cord

(C) Lumbar cord

(D) Sacral cord

5–d. The sacral cord contains the sacral parasympathetic nucleus (S2–S4); this gives

rise to preganglionic fibers that synapse in the intramural ganglia of the pelvic

viscera.

@6. Which of the following spinal cord levels Contains the brachial plexus

(A) Cervical cord


(C) Lumbar cord

(D) Lower thoracic cord

(E) Coccygeal cord

6–A. The cervical cord contains massive ventral horns, which give rise to the brachial

plexus (C5–C8)

@7. Which of the following spinal cord levels Has a ciliospinal center of Budge

(A) Cervical cord (


(C) Lumbar cord


7–B. The ciliospinal center of Budge is found in the lateral horn at T1. This

sympathetic nucleus innervates the radial muscle of the iris (dilator pupillae) and the

nonstriated superior and inferi- or tarsal (Müller) muscles.

@8. Which of the following spinal cord levels Contains the spinal accessory nucleus

(CN XI)

(A) Cervical cord


(C) Lumbar cord


8–A. The spinal accessory nucleus extends from C1 to C6 and gives rise to the spinal

root of the spinal accessory nerve; it innervates the sternocleidomastoid and trapezius

muscles.

@9. Which of the following spinal cord levels Contains the phrenic nucleus

(A) Cervical cord


(C) Lumbar cord


9–A. The phrenic nucleus extends from C3 to C6 and innervates the diaphragm.

160398066-quiz-2

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