Spinal Cord

Question 1

What is a spinal cord segment?

Answer 1

• Each spinal cord segment gives rise to a pair of spinal nerves.
• Sections of spinal cord, spinal cord itself
• CNS structure

Question 2

What is a spinal nerve?

Answer 2

Forming of dorsal/ventral roots

-PNS structure

Question 3

Cervical nerves do what?

Answer 3

Exit above the same numbered vertebra.

-C8 nerve exits inferior to C7 vertebra and superior to the T1 vertebra.

Question 4

Thoracic, lumbar and sacral nerves do what?

Answer 4

Exit below the same numbered vertebrae.

Question 5

The spinal cord is what?

Answer 5

Shorter than the vertebral column.

-Ends between T11 and L3 vertebrae.

Question 6

What is the most inferior part of the spinal cord?

Answer 6

Conus Medullaris

Question 7

The more inferior you go on the spinal cord?

Answer 7

The greater the distance between the spinal cord segment and its corresponding numbered bone.

Question 8

Dorsal and ventral roots do what on the spinal cord?

Answer 8

Run inferiorly within the spinal cord to get to their respective vertebral foramina before joining together to create the spinal nerves.

Question 9

Cauda equina is what?

Answer 9

Lumbar and sacral nerve roots below the conus medullaris

-Horse tail

Question 10

Segments of the spinal cord are part of what subdivision?

Answer 10

CNS

Question 11

What is the filum terminale?

Answer 11

• Connective tissue

- Prevents superior displacement of the spinal cord (anchors the spinal cord down)

Question 12

What is the denticulate ligament?

Answer 12

Longitudinal thickening of the pia mater.
-Anchors the spinal cord laterally to the dura mater stabilizing the spinal cord within the vertebral canal during movement.

Question 13

What does gray matter contain?

Answer 13

Ventral horn
Lateral horn
Dorsal horn
-Composed of mainly of neuron cell bodies.

Question 14

What is the ventral horn?

Answer 14

voluntary motor neuron somas

Question 15

What is the lateral horn?

Answer 15

• Interomediolateral cell column.
• Only found T1-L2(3)
• Contains presynaptic sympathetic motor neuron somas

Question 16

What is the dorsal horn?

Answer 16

Interneuron somas, sensory axons and axton terminals

Question 17

What is white matter?

Answer 17

Ascending and descending nerve tracts/fasciculi

• Axons of neurons carrying information to higher centers
• Axons of neurons carrying information to the spinal cord from higher centers.
• Composed of axons surrounded by large quantities of myelin.

Question 18

What is a group of cell bodies in the PNS called?

Answer 18

ganglia

Question 19

What is a group of cell bodies called in the CNS?

Answer 19

Nuclei

Question 20

Gray matter on the surface of the brain is called?

Answer 20

Cortex

Question 21

Ventral rootlets form a single segment coalesce to form a?

Answer 21

Ventral root

Question 22

What does the dorsal root contain?

Answer 22

Sensory axons that bring information into the spinal cord and enters the posterolateral spinal cord via rootlets.

Question 23

What is a dorsal root ganglion?

Answer 23

Located outside the spinal cord

-Contains the cell bodies of sensory neurons.

Question 24

A spinal nerve is joined from?

Answer 24

A dorsal and ventral root

• A mixed nerve because it contains both sensory and motor axons.
• Spinal nerves are located in the intervertebral foramen.

Question 25

What does the ventral root contain?

Answer 25

motor axons

Question 26

Why are spinal nerves unique?

Answer 26

They carry all of the motor and sensory axons of a single spinal segment.

Question 27

What does the dorsal rami innervate?

Answer 27

The paravertebral muscles, posterior parts of the vertebrae and overlying cutaneous areas.

Question 28

What does the ventral rami innervate?

Answer 28

The skeletal muscles, muscular and cutaneous areas of the limbs and of the anterior and lateral trunk.