# 1. Anatomy

Question 1

Name the meninges and the spaces.

Answer 1

• epidural space
  1. dura mater
• subdural space
  2. arachnoid mater
• subarachnoid space
  3. pia mater

Question 2

Describe the dura mater

Answer 2

• most superficial
• dense irregular CT
• tough momma

Question 3

Describe the arachnoid mater

Answer 3

• middle layer
• avascular
• delicate collagen fibers and some elastic fibers

Question 4

What is in the subarachnoid space?

Answer 4

cerebral spinal fluid (CSF)

Question 5

Describe the pia mater

Answer 5

• innermost layer
• thin and transparent (saran wrap)
• adheres to surface of spinal cord & brain
• lots of blood vessels to supply spinal cord

Question 6

What are denticulate ligaments?

Answer 6

• extensions of pia mater that suspend the spinal cord in the middle
• protect against sudden displacement

Question 7

What is the length of the spinal cord?

Answer 7

from the medulla oblongata to L2 (more specifically between L1 and L2)
-newborns can extend to L3 or L4.

Question 8

Where are the enlargements in the spinal cord?

Answer 8

• cervical enlargement - from C4-T1; nerves to and from the arms
• lumbar enlargement - from T9-T12; nerves to and from the legs

Question 9

What is the conus medullaris?

Answer 9

-end of the spinal cord

Question 10

What are filum terminale?

Answer 10

• extensions of pia mater that runs from conus medullaris to coccyx
• anchors the spinal cord to the coccyx

Question 11

What is the cauda equina?

Answer 11

• the spinal nerves at the end of the spinal cord that don’t exit the vertebral column when they exit the cord. (ie. the L5 spinal nerve exits the spinal cord at L2 but stays in the vertebral column until L5)
• looks like a horses tail

Question 12

What are rootlets?

Answer 12

bundles of axons that come directly off the spinal cord

Question 13

What are the protective structures of the spinal cord?

Answer 13

1. vertebral column
2. CSF
3. meninges

Question 14

Which root has sensory axons?

Answer 14

Posterior (dorsal) root

Question 15

Which root has motor axons?

Answer 15

Anterior (ventral) root

Question 16

True or False: The posterior root contains efferent axons.

Answer 16

False. The posterior root (sensory axons) is afferent (going towards the spinal cord). The anterior root (motor axons) is efferent (traveling away from the spinal cord)

Question 17

Where are sensory cell bodies located?

Answer 17

in the posterior (dorsal) root ganglion.

Question 18

Where are motor cell bodies located?

Answer 18

in the CNS (anterior grey horn or the brain)

Question 19

Why is white matter white?

Answer 19

because the bundles of axons are myelinated

Question 20

What makes up the grey matter?

Answer 20

• dendrites and cell bodies of neurons
• unmyelinated axons
• neuroglia

Question 21

What is the area of grey matter that connects the two sides called?

Answer 21

the grey commissure

Question 22

What is the central canal?

Answer 22

a canal that runs down the center of the whole spinal cord and is filled with CSF

Question 23

What is in the posterior grey horn?

Answer 23

incoming sensory axons and cell bodies of interneurons

Question 24

What is in the anterior grey horn?

Answer 24

motor cell bodies

Question 25

What is in the lateral grey horn?

Answer 25

autonomic cell bodies

Question 26

Where is the lateral grey horn located?

Answer 26

only in the thoracic-upper lumbar region

Question 27

What are bundles of axons in the CNS called?

Answer 27

tracts

Question 28

What are bundles of axons in the PNS called?

Answer 28

nerves

Question 29

What are clusters of cell bodies in the CNS called?

Answer 29

nuclei

Question 30

What are clusters or cell bodies in the PNS called?

Answer 30

ganglion

Question 31

What the layers of spinal nerves?

Answer 31

endoneurium, perineurium, epineurium

Question 32

What is the endoneurium?

Answer 32

- the innermost layer of spinal nerves | - wraps individual axons

Question 33

What is the perineurium?

Answer 33

- the middle layer of spinal nerves | - wraps fascicles

Question 34

What is the epineurium?

Answer 34

- the outer layer of spinal nerves | - wraps entire nerve

Question 35

What are names the of Rami?

Answer 35

1. posterior (dorsal) ramus 2. anterior (ventral) ramus 3. meningeal branch 4. rami communicantes

Question 36

Where does the posterior ramus go?

Answer 36

to the posterior. - muscles & skin of posterior trunk

Question 37

Where does the anterior ramus go?

Answer 37

to the limbs (muscles and skin), anterior and lateral trunk | -looks like a continuation of spinal nerves

Question 38

Where does the meningeal branch go?

Answer 38

- back to the vertebral canal | - supplies vertebrae, vertebral ligaments, blood vessels of spinal cord & meninges.

Question 39

Where does the rami communicantes go?

Answer 39

the autonomic nervous system

Question 40

What are the blood vessels that supply nerves called?

Answer 40

vasa neuvorum