Spinal Cord and Meninges

Question 1

Where do spinal nerves pass out of the Vertebral Canal?

Answer 1

Intervertebral Foramina (formed by Superior and Inferior Vertebral Notches on Adjacent Vertebrae)

Question 2

How many cervical vertebrae/spinal nerves

Answer 2

7 Cervical Vertebrae

8 Pairs Spinal Nerves

Question 3

How many thoracic vertebrae/spinal nerves

Answer 3

12 Thoracic Vertebrae

12 Pairs Thoracic Spinal Nerves

Question 4

How many Lumbar vertebrae/spinal nerves

Answer 4

5 Lumbar Vertebrae

5 Pairs Lumbar Spinal Nerves

Question 5

How many Sacral vertebrae/spinal nerves

Answer 5

5 Sacral Vertebrae

5 Pairs Sacral Spinal Nerves

Question 6

How many Coccygeal vertebrae/spinal nerves

Answer 6

1 Coccygeal bone (multiple fused)

1 Nerve

Question 7

Where do C1-C7 spinal nerves pass out?

Answer 7

Above their corresponding vertebrae

Question 8

Where does C8 spinal nerve pass out?

Answer 8

Below C7 Vertebrae

Question 9

Where do T1 and below Spinal nerves pass out?

Answer 9

Below their corresponding vertebrae

Question 10

What is the Cervical Enlargement

Answer 10

Enlargement of the VGH as motor fibres to Brachial Plexus arise

Question 11

What is the Lumbar/Sacral Enlargement

Answer 11

Enlarged VGH as motor fibres to the Lumbosacral plexus arise

Question 12

Conus Medullaris

Answer 12

Tapered end of the SC within the SC

Question 13

Level of Conus Medullaris in adults

Answer 13

L1-L2

Due to SC regression during growth

Question 14

Level of Conus Medullaris in neonates

Answer 14

L3-L4

Question 15

Filum Terminale

Answer 15

Modification of Pia Mater from Conus Medullaris to Co1

Gives Longitudinal support to SC

Question 16

Approximate length of Filum Terminale

Answer 16

20cm

Question 17

Lumbar Cistern

Answer 17

Enlargement of Subarachnoid Space beneath level of the CM

Question 18

Contents of the Lumbar Cistern

Answer 18

CSF
Filum Terminale
Cauda Equina

Question 19

Clinical significance of Lumbar Cistern

Answer 19

Site of Lumbar Puncture (L4-L5) as less chance of damaging nerves

Surface landmark: Posterior Iliac Crest

Question 20

Cauda Equina

Answer 20

Bundle of nerves associated with vertebrae below level of CM. Nerves descend in bundle to appropriate IVF

Question 21

Sx of Cauda Equina Syndrome

Answer 21

Micturition Difficulties
Loss of Anal Sphincter Tone (Incontinence)
Saddle Anaesthesia
Lower Back/Leg Pain

Question 22

Blood Supply to the Spinal Cord

Answer 22

2 Posterior Spinal As
1 Anterior Spinal As
8-10 Segmental Medullary As/Radicular As (arising from Posterior Intercostal As)

Question 23

Venous Drainage of SC

Answer 23

Anterior/Posterior Spinal Veins

Drain into Internal Vertebral Plexus in Epidural Fat

Drains into large systemic veins and Azygous system

Question 24

At which levels is the Lateral Grey Horn present, and why?

Answer 24

T1-L2
S2-S4

Sympathetic chain/splanchnic nerves arise at these levels

Question 25

Dura mater in the SC?

Answer 25

Only one layer (meningeal)

Periosteal layer reflects and adheres to external bone of skull

Question 26

Denticulate Ligaments

Answer 26

Modifications of Pia mater that project to lateral walls of Vertebral Canal

Stabilise the SC

Question 27

Types of fibres in Dorsal Root

Answer 27

Sensory (somatic and visceral)

Cell bodies in DRG

Question 28

Types of fibres in Ventral Root

Answer 28

Somatic Motor
Visceral Motor

(separate to one another. Cell body in VGH)

Question 29

Superior and Inferior limits of Epidural/Extradural Space?

Answer 29

Foramen Magnum

Sacrococcygeal Membrane @ tip of sacrum

Question 30

Superior and Inferior limits of Subarachnoid Space?

Answer 30

Cerebral Cortex

S2