Chapter 13: Spinal Region

Chapter 13: Spinal Region

Complete Chapter Questions With Answers

Sample Questions Are Posted Below

1. Reciprocal activation of a stepping pattern generator (SPG) is thought to be coordinated by signals conveyed in the:
2. DCML.
3. Golgi tendon organs (GTOs).
4. Posterior commissure of spinal cord.
5. Anterior commissure of spinal cord.
6. Ventral horn gamma motor neurons.

ANS: B

Rationale: Reciprocal activation of stepping pattern generators is essential for swing phase of one lower limb to occur simultaneously with the stance phase of the other lower limb. The signals to coordinate the right and left stepping pattern generators are conveyed in the anterior commissure of the spinal cord.

2. Which one of the following is NOT a sign of an upper motor neuron lesion?
3. Muscle paresis
4. Hyperreflexia
5. Muscle fasciculations
6. Positive Babinski’s sign
7. Spasticity

ANS: C

Rationale: Muscle paresis, hyperreflexia, positive Babinski’s sign, and spasticity are all signs of an upper motor neuron (UMN) lesion. Dystonia is a basal ganglia sign and does not occur in UMN lesions.

3. After a complete spinal cord injury affecting S2-4, a bladder that cannot be emptied is which of the following?
4. Hypertonic and hyperreflexive
5. Flaccid and paralyzed
6. Spastic
7. Autoreflexive
8. None of the above

ANS: B

Rationale: Complete lesions that damage any part of the reflexive bladder emptying circuit, that is, levels S2-S4—or afferents or parasympathetic efferents—produce a flaccid, paralyzed bladder. With an S2-4 lesion, the sympathetic efferents are intact and their signals inhibit contraction of the bladder wall and facilitate closure of the internal spincter. Complete lesions above the sacral cord interrupt descending axons that normally control bladder function but do not interrupt sacral level reflexive control of the bladder. This results in a hypertonic, hyperreflexive bladder with reduced bladder capacity. Hyperreflexive bladder and spastic bladder are synonymous. Autoreflexive is not a neuroscience term.

4. Complete spinal cord lesions above which one of the following levels results in long-term ventilator dependence?
5. C4
6. C5
7. C6
8. C7
9. All of the above

ANS: A

Rationale: Lesions above C4 interrupt most fibers of the phrenic nerve (C3 and C5 make small contributions to the phrenic nerve), so the diaphagm does not receive adequate signals for breathing. If C4 is intact, the diaphragm receives adequate signals for breathing.