1. The nervous system is anatomically separated into two parts: the central nervous system and
the peripheral nervous system. The central nervous system consists of the _________________________
inside the cranium, and the _________________________________ inside the spinal column.
2. Examine the view from either side and use it to answer the following questions.
a. Select any part of the outer protective connective tissue layer surrounding the spinal cord.
This layer is called the _____________________________. This tough structure also protects the brain.
b. Use the Hide tool to remove the outer protective layer from the view, and then select the
spinal cord. Use the book icon to read its definition. The spinal cord extends from the upper
border of the spinal column (atlas) to the lower border of the first, or upper border of the
second, ______________________________ vertebra.
c. What part of the brain is continuous with the spinal cord?
3. Paired spinal nerves exit the spinal cord along its length, forming the peripheral nervous system.
Select any part of a spinal nerve, and then use the arrow in the content box to choose Peripheral from
the selected structures list. Use the book icon to read a description of the peripheral nervous system.
a. How many pairs of spinal nerves are there?
b. Why are spinal nerves called mixed nerves?