222 Introduction to Anatomy and Physiology
Lesson 6.4 Review and Assessment
Mini Glossary
Make sure you that know the meaning of each key term.
cranial nerves 12 pairs of nerves
that originate in the brain and relay
impulses to and from the PNS
craniosacral division the
parasympathetic nervous system, in
which nerves originate in the brain
stem or sacral region of the spinal
cord
dorsal ramus the division of posterior
spinal nerves that transmit motor
impulses to the posterior trunk
muscles and relay sensory impulses
from the skin of the back
endoneurium a delicate, connective
tissue that surrounds each nerve
fi ber
epineurium the tough outer covering
of a nerve
ganglion a mass of nervous tissue
composed mostly of nerve-cell bodies
norepinephrine a neurotransmitter
released by postganglionic neurons
in the sympathetic nervous system
paravertebral ganglia mass of nerve
cell bodies close to the spinal cord
perineurium a protective sheath that
surrounds a bundle of nerve fi bers
plexuses complex interconnections
of nerves
postganglionic neuron the second
neuron in a series that transmits
impulses from the CNS
preganglionic neuron the fi rst
neuron in a series that transmits
impulses from the CNS
spinal nerves neural transmitters
that branch from the left and right
sides of the spinal cord
thoracolumbar division the
sympathetic system of nerves that
lies near the thoracic and lumbar
regions of the spine
ventral ramus the anterior division of
spinal nerves that communicate with
the muscle and skin of the anterior
and lateral trunk
Know and Understand
1. Explain the function of the peripheral nervous
system.
2. What is the major purpose of the endoneurium,
perineurium, and epineurium combined?
3. How would you describe cranial nerves in terms
of sensory and motor fi bers?
4. From where do the majority of cranial nerves
emanate?
5. Are spinal nerves efferent, afferent, or mixed?
6. Which nervous system sends impulses to the
heart—the somatic or the autonomic system?
7. Why is the parasympathetic nervous system also
known as the craniosacral division?
8. Explain the difference between a preganglionic
neuron and a postganglionic neuron.
Analyze and Apply
9. Explain how the structure of a nerve decreases
the chances of nerve damage.
Build vocabulary with
e-fl ash cards and games
Assess
sympathetic nerves and explain how it could be a
lifesaver.
11. Neurons meet at junctions called ganglions.
Explain the purpose of a ganglion and how
these structures help transmit nerve impulses
throughout the body.
12. Explain how the function of a cranial nerve might
determine whether it is a sensory or motor fi ber,
or both.
13. Using clay, create a model of a nerve. Use
different colors for the different parts of the nerve.
Begin with a simpler structure, such as an axon,
and continue until you have a more complex
structure (complete nerve). Use the illustrations
in this lesson to guide you in constructing your
model.
In the Lab
e