Spinal Cord and its Blood Supply

Question 1

What is the conus medullaris?

Answer 1

The lower end of spinal cord (spine tapers into cone)

Question 2

What are denticulate ligaments?

Answer 2

Wing-like leaves of pia extending laterally between dorsal and ventral roots

Question 3

How many bilaterally paired spinal nerves are there?

Answer 3

31

Question 4

What fibres do posterior nerve roots carry?

Answer 4

sensory fibres

Question 5

Where are the cell bodies of posterior nerve roots located?

Answer 5

The posterior root ganglia

Question 6

What fibres do the anterior nerve roots carry?

Answer 6

motor fibres

Question 7

Where are the cell bodies of the anterior nerve roots located?

Answer 7

anterior horn of grey matter

Question 8

Where do the anterior and posterior nerve roots unite?

Answer 8

In the intervertebral foramina (cervical and sacral segments are exception)

Question 9

What does gray matter consist of?

Answer 9

Neuronal cell bodies

Question 10

What is Rexeds laminae?

Answer 10

The ten divisions of gray matter

Question 11

Which laminae are located in the posterior horn?

Answer 11

laminae I-V

Question 12

What do medial fibre types consist of?

Answer 12

Mechanoreceptors

Question 13

What do lateral fibre types consist of?

Answer 13

Nociceptors

Question 14

Which laminae are confined to the anterior horn?

Answer 14

Laminae VIII and IX

Question 15

What does lamina IX contain?

Answer 15

a and y motorneurons that innervate skeletal muscle

Question 16

What does the lateral horn contain?

Answer 16

intermediate gray matter of laminae VII

Question 17

What is significant about lamina VII

Answer 17

Its is the site for the lateral horn at thoracic/lumbar/sacral levels where sympathetic and parasympathetic cell bodies are located
Also contains Nucleus Dorsalis

Question 18

Where is lamina X located?

Answer 18

It encircles central canal

Question 19

What arteries supply the spinal cord?

Answer 19

The anterior and posterior spinal arteries

Question 20

How is single vertebral artery formed?

Answer 20

Unification of anterior spinal branches and vertebral arteries on each side

Question 21

Where do the right and left posterior vertebral arteries arise?

Answer 21

from the posterior inferior cerebellar arteries or directly from vertebral arteries

Question 22

What level is the cervical enlargement at?

Answer 22

C4-T1

Question 23

Why is there a cervical enlargement?

Answer 23

For the brachial plexus

Question 24

What level is the lumbar enlargement at?

Answer 24

T9-L1

Question 25

What are the filum terminale?

Answer 25

extensions of pia matter from conus medullaris

Question 26

What do spinal nerves originate as?

Answer 26

Rootlets attached to sulci of anterior and posterior root zones

Question 27

Where do 1st and 2nd cervical nerve roots unite?

Answer 27

Lateral to intervertebral foramina, in contact with vertebral arteries

Question 28

Where do sacral nerve roots unite?

Answer 28

inside vertebral canal

Question 29

Which spinal segments possess lateral horns of grey matter?

Answer 29

thoracic, upper lumbar and sacral segments

Question 30

What is lamina II?

Answer 30

Substansia gelatinosa- C fibres terminate here

Question 31

What is lamina I?

Answer 31

zona marginalis

Question 32

Which laminae do A delta fibres terminate in?

Answer 32

Laminae III-V- Nucleus Proprius

Question 33

Where doe gating of pain conduction occur?

Answer 33

Substansia Gelatinosa

Question 34

What is nucleus dorsalis?

Answer 34

Origin of spinocerebellar tracts

Question 35

What do radicular arteries end as?

Answer 35

Pial arteries