Spinal Cord

Question 1

What protects the spinal cord?

Answer 1

Skin, epaxial muscles, vertebrae, meninges. It is very well protected.

Question 2

List the meninges from outer to inner layers.

Answer 2

1. Dura mater 2. Arachnoid 3. Pia mater

Question 3

What is the delicate layer with spider web-like filaments?

Answer 3

Arachnoid layer

Question 4

Where is the CSF found?

Answer 4

In the subarachnoid space.

Question 5

What is the subdural space?

Answer 5

A vascular layer that is associated with the dura.

Question 6

Which of the meninges is adhered to the spinal cord and brain?

Answer 6

Pia mater

Question 7

Which layer is fused with the periosteum in the cranial cavity?

Answer 7

Dura mater

Question 8

____ form an envelope that completely encloses the brain and spinal cord.

Answer 8

The meninges

Question 9

Where is the epidural space? What fills this space?

Answer 9

Between the vertebrae and dura mater. Contains fat and fluid.

Question 10

What are denticulate ligaments?

Answer 10

Connections from the dura to spinal cord, helps with stabilization.

Question 11

What is a complete dorsal laminectomy?

Answer 11

A procedure where the laminae of the vertebral column are cut and removed to expose the spinal cord.

Question 12

What is a hemilaminectomy?

Answer 12

A procedure where one side of the vertebral column is cut at the laminae to expose the spinal cord.

Question 13

How does the length of the spinal cord compare to the length of the vertebral column. What is the consequence of that?

Answer 13

The spinal cord is shorter. Spinal nerves start coming off straight but become more parallel to the spinal cord dorsally.

Question 14

What are the thickenings of the spinal cord called?

Answer 14

Brachial plexus and lumbosacral plexus.

Question 15

What is the structure at the end of the spinal cord that is the shape of a cone?

Answer 15

Medullary cone.

Question 16

What is the collection of spinal nerves at the end of the spinal cord called?

Answer 16

Cauda equina.

Question 17

Where does the spinal cord end?

Answer 17

Around the ilium.

Question 18

Where is CSF fluid collected or anesthetic administered in the caudal part of the spinal cord?

Answer 18

Lumbosacral interarcurate space.

Question 19

Where is the lumbosacral interarcurate space?

Answer 19

Depends on species - cranial to the sacrum.

Question 20

Where are epidural anesthetics administered?

Answer 20

Very caudally, more caudal than the lumbosacral interarcurate space.

Question 21

What is the filum terminale?

Answer 21

A small string-like structure coming off the end of the spinal cord. Terminates on the caudal vertebrae. Most caudal anchor point.

Question 22

How many cranial spinal nerves are there?

Answer 22

8 - named by the vertebrae caudal to them. C8 is caudal to C7 vertebra and cranial to T1.

Question 23

How many thoracic nerves are there?

Answer 23

Same # as vertebrae

Question 24

How many lumbar nerves are there?

Answer 24

Same # as vertebrae

Question 25

How many sacral nerves are there?

Answer 25

Same # as vertebrae

Question 26

How many caudal vertebrae are there?

Answer 26

Same # as vertebrae

Question 27

Where are neuronal cell bodies found in the spinal cord?

Answer 27

Grey matter - Inside of spinal cord.

Question 28

What are ganglia?

Answer 28

Structures outside of the spinal cord that contain neuronal cell bodies.

Question 29

Central grey matter changes based on....

Answer 29

Location in the spinal cord, larger if there are more neuronal cell bodies.

Question 30

What do the two branches of a spinal nerve innervate?

Answer 30

Dorsal rami - epaxial muscles. Ventral rami - hypaxial muscles and other structures.

Question 31

Which ramus of a spinal nerve is bigger?

Answer 31

Ventral ramus - innervates more.

Question 32

Where is the spinal nerve formed? What happens immediately after its formation.

Answer 32

Formed after ganglia, splits into two rami.

Question 33

The dorsal root contains...

Answer 33

Afferent neurons

Question 34

The ventral root contains...

Answer 34

efferent neurons.

Question 35

What is the direction of axons in the dorsal root?

Answer 35

Axons enter spinal cord.

Question 36

Where are the dendrites of the ventral root?

Answer 36

In the ventral horn.

Question 37

Do dorsal root or ventral root neurons have long dendrites?

Answer 37

Dorsal root.

Question 38

Where are the cell bodies of ventral root neurons.

Answer 38

Ventral horn

Question 39

Why are spinal nerves called mixed nerves?

Answer 39

There are 4 different pathways in the nerve (somatic afferent, somatic efferent, visceral afferent, visceral efferent).

Question 40

What are funiculi?

Answer 40

Regions of the white matter. Composed of ascending and descending nerve fibers that are grouped to form tracts.

Question 41

Dorsal funiculus is mainly composed of...

Answer 41

ascending tracts (towards the brain)

Question 42

Lateral funiculus contains...

Answer 42

Ascending (laterally) and ascending/descending (medially) tracts

Question 43

Ventral funiculus contains...

Answer 43

Both ascending and descending tracts

Question 44

Spinal nerves exit through...

Answer 44

intervertebral foramen.

Question 45

Spinal nerves innervate _____ while plexus nerves innervate _____.

Answer 45

Spinal = trunk elements. Plexus = limbs.

Question 46

The intrinsic limb muscles are innervated by...

Answer 46

the ventral ramus of spinal nerves.

Question 47

The arterial supply of the spinal column includes...

Answer 47

A ventral spinal artery and 2 dorsolateral arteries.

Question 48

The venous supply of the spinal cord involves...

Answer 48

a plexus.

Question 49

Inside the spinal cord, the venous system is called _____. As it exits, it is called _____.

Answer 49

Inside = plexus. Outside = intervertebral vein.