Chapter 13 Review KEY
#1-4, 7, 10-13 & 18
1.
2.
3.
4.
7.
B
C
C
(1) E, (2) D, (3) C, (4) G, (5) B, (6) F, (7) A
( 1) b, l (2) a, 3 and 5 (3) a, 4 (4) a, 2 (5) c, 2
10. The PNS includes all nervous tissue outside the CNS: the sensory receptors, the peripheral nerves (cranial
or spinal), the ganglia, and motor nerve endings. The peripheral nerves transmit sensory and motor impulses,
the ganglia contain cell bodies of somatic or autonomic nerve fibers, the sensory receptors receive stimuli, and
the motor end plates release neurotransmitters that regulate the activity of effectors.
11. In the PNS, macrophages and Schwann cells aid the regeneration process physically and chemically.
Macrophages fail to aid the process in the CNS. Further, oligodendrocytes die and thus do not aid fiber
regeneration.
12. a. Spinal nerves form from dorsal and ventral roots that unite distal to the dorsal root ganglion. Spinal
nerves are mixed.
b. The ventral rami, with the exception of those in the thorax that form the intercostal nerves, contribute to
large plexi that supply the anterior and posterior body trunk and limbs. The dorsal rami supply the
muscles and skin of the back.
13. a. A plexus is a branching nerve network formed by roots from several spinal nerves that ensures that any
damage to one nerve root will not result in total loss of innervation to that part of the body.
b.
Cervical Plexus (neck & shoulder)
Brachial Plexus (arm)
Lumbar Plexus
(anterior leg)
Sacral Plexus
(posterior leg)
18. Reflex tests assess the condition of the nervous system. Exaggerated, distorted, or absent reflexes indicate
degeneration or pathology of specific regions of the nervous system often before other signs are apparent.