Unit 1: Lecture 9

Question 1

The spinal cord is a collection of…

Answer 1

• neuron cell bodies
• axons
• glial cells

Question 2

Segments mark point of…

Answer 2

exit for the spinal nerves

Question 3

How many spinal segments?

Answer 3

31

Question 4

Split up the 31 spinal segments:

Answer 4

Cervical - 8
Thoracic - 12
Lumbar - 5
Sacral - 5
Coccyx - 1

Question 5

How many pairs of spinal nerves?

Answer 5

31

Question 6

Spinal nerve is comprised of…

Answer 6

a DORSAL root and a VENTRAL root

Question 7

What nerves are formed immediately after the spinal nerve is formed?

Answer 7

Peripheral nerves

Question 8

Groupings of peripheral nerves are called…

Answer 8

Plexi

Question 9

Four different plexi that are formed directly from spinal nerves:

Answer 9

1. Cervical plexus (C1 - C4)
2. Brachial plexus (C5 - T1)
3. Lumbrosacral plexus (L1 - S4)
4. Coccygeal plexus (S4, S5, and 1st Coccygeal)

Question 10

How long is adult spinal cord?

Answer 10

58-60 cm
23-24 in
~ 2 ft

Question 11

Where does spinal cord begin and end?

Answer 11

Begins at foramen magnum and ends are conus medullaris

Question 12

Where is conus medullaris found?

Answer 12

At the L1-L2 intervertebral disc

Question 13

While the spinal cord doesn’t run the length of the vertebral column, the _________ ends at S2 and contains __________

Answer 13

Dura mater; cerebrospinal fluid

Question 14

Cervical enlargement

Answer 14

• C5 - T1

- Brachial plexus found here

Question 15

Lumbosacral enlargement

Answer 15

• L1 - S4
• Lumbrosacral plexus found here
• Cauda equine formed from rootlets of lumbrosacral plexus

Question 16

Filum terminale

Answer 16

Ligamentous structure that anchors inferior tip of spinal cord to the coccyx

Question 17

Filum terminal composed of…

Answer 17

glial cells and pia mater

Question 18

Meninges (deep to superficial)

Answer 18

Pia mater
- Denticulate ligaments (21 pairs)
Arachnoid layer
- Subarachnoid Space (between arachnoid and pia)
Dura mater
- Epidural space (between Dura and vertebral canal)

Question 19

White matter

Answer 19

• Myelinated axons

- makes up EXTERNAL portion of spinal cord

Question 20

Gray matter

Answer 20

• composed of neuron cell bodies

- forms “butterfly”

Question 21

Sulci/fissures

Answer 21

Splits in the spinal cord (dorsal median sulcus & ventral median fissure)

Question 22

Dorsal root ganglia are located in the…

Answer 22

intervertebral foramina of the vertebral column

Question 23

Posterior spinal arteries

Answer 23

Paired, derived from vertebral arteries, running posteriorly.

Supply 1/3 of spinal cord

Question 24

Anterior spinal artery

Answer 24

Singular, derived from vertebral arteries, runs anteriorly (anterior median fissure)

Larger than either of the posterior spinal arteries

Supplies lower 2/3

Question 25

Feeder arteries

Answer 25

Segmental spinal arteries on either side of spinal cord.

Each divides into an anterior & posterior radicular artery, which joins the anterior and posterior spinal artery, respectively.

Question 26

Great Anterior Medullary Artery of Adamkiewicz

Answer 26

Unilateral artery, generally entering the spinal cord from the left side in the lower thoracic region

Question 27

Dermatome

Answer 27

Area of skin supplied by a single spinal cord segment