Chapter 14 - Review Questions
14. The middle layer of connective tissue that surrounds each peripheral nerve is the epineurium. perineurium. endoneurium. endomysium.
b
17. The gray matter of the spinal cord is dominated by myelinated axons only. cell bodies of neurons and neuroglia. unmyelinated axons only. Schwann cells and satellite cells.
b
18. The ________________________is a strand of fibrous tissue that provides longitudinal support as a component of the coccygeal ligament. conus medullaris filum terminale cauda equina dorsal root
b
19. Axons crossing from one side of the spinal cord to the other within the gray matter are found in the anterior horns. white commissures. gray commissures. lateral horns.
c
20. The paired structures that contain cell bodies of sensory neurons and are associated with each segment of the spinal cord are the dorsal rami. ventral rami. dorsal root ganglia. ventral root ganglia.
c
12. Sensory and motor innervations of the skin of the lateral and anterior surfaces of the body are provided by the white rami communicantes. gray rami communicantes. dorsal ramus. ventral ramus.
d
13. The brachial plexus a. innervates the shoulder girdle and the upper extremity. b. is formed from the ventral rami of spinal nerves C5-T5. c. is the source of the musculocutaneous, radial, median, and ulnar nerves. d. all of the above
d
15. The expanded area of the spinal cord that supplies nerves to the pectoral girdle and upper limbs is the conus medullaris. filum terminale. lumbosacral enlargement. cervical enlargement.
d
2.1 What nerve is likely to transmit pain when a person receives an intramuscular injection into the deltoid region of the arm? ulnar nerve radial nerve intercostobrachial nerve upper lateral cutaneous nerve of the arm
d
2.2 Which of the following actions would be compromised if a person suffered an injury to lumbar spinal segments L3 and L4? performing a plié (shallow knee bend) in ballet sitting cross-legged in the lotus position (lateral side of the foot on the medial side of opposite thigh) riding a horse all of the above
d
21. The deep crease on the anterior surface of the spinal cord is the posterior median sulcus. posterior median fissure. anterior median sulcus. anterior median fissure.
d
How does a reflex differ from a voluntary muscle movement?
A reflex is an immediate involuntary response, whereas voluntary motor movement is under conscious control and is voluntary.
Why are there eight cervical spinal nerves but only seven cervical vertebrae?
In the cervical region, the first pair of spinal nerves, C1, exits between the skull and the first cervical vertebra. Thereafter, a numbered cervical spinal nerve exits after each cervical vertebra. For instance, nerve C2 exits after vertebra C1, nerve C3 exits after vertebra C2, and so on until nerve C8, which exits after vertebra C7C7.
If the dorsal root of the spinal cord were damaged, what would be affected?
Incoming sensory information would be disrupted.
Why is it important that a spinal tap be done between the third and fourth lumbar vertebrae?
The adult spinal cord extends only as far as vertebra L1 or L2. Inferior to this point in the vertebral foramen, the meningeal layers enclose the relatively sturdy components of the cauda equina and a significant quantity of CSF.
What prevents side-to-side movements of the spinal cord?
The denticulate ligaments prevent side-to-side movements of the spinal cord.
What is the role of the meninges in protecting the spinal cord?
The meninges provide a tough protective covering, longitudinal physical stability, and a space for shock-absorbing fluid.
Karen falls down a flight of stairs and suffers spinal cord damage due to hyperextension of the cord during the fall. The injury results in edema of the spinal cord with resulting compression of the anterior horn cells of the spinal region. What signs would you expect to observe as a result of this injury?
The neurons for the anterior horn of the spinal cord are somatic motor neurons that direct the activity of skeletal muscles. The lumbar segments of the spinal cord control the skeletal muscles that are involved with the control of the muscles of the hip and lower limb. As a result of the injury, Karen would have poor control of most lower limb muscles, a problem with walking (if she could walk at all), and (if she could stand) problems maintaining balance.
Cindy is in an automobile accident and injures her spinal cord. She has lost feeling in her right hand, and her doctor tells her that it is the result of swelling compressing a portion of her spinal cord. Which part of her cord is likely to be compressed?
The part of the cord that is most likely compressed is an ascending tract.
The incision that allows access to the abdominal cavity involves cutting the sheath of the rectus abdominis. This muscle is always retracted laterally, never medially. Why?
The rectus abdominis muscle is always retracted laterally, as it is innervated by T7−T12, entering through the posterior aspect along the lateral margin. If the muscle were to be retracted medially, the nerves would be torn, thereby paralyzing the muscle.
Why is response time in a monosynaptic reflex much faster than response time in a polysynaptic reflex?
Transmission of information between neurons at synapses takes a finite amount of time. Thus, the more synapses in a reflex, the longer the delay between the stimulus and responses. In a monosynaptic reflex, there is only one synapse. It has the most rapid response time. In a polysynaptic reflex, there are multiple synapses, each contributing to the overall delay.
16. Spinal nerves are called mixed nerves because they contain sensory and motor fibers. they exit at intervertebral foramina. they are associated with a pair of dorsal root ganglia. they are associated with dorsal and ventral roots.
a
2.3 Tingling and numbness in the palmar region of the hand could be caused by compression of the median nerve in the carpal tunnel. compression of the ulnar nerve. compression of the radial artery. irritation of the structures that form the superficial arterial loop.
a
