Spinal Cord and Spinal Nerves

Question 1

How many vertebrae are in each compartment of the vertebral column?

Answer 1

• 7 Cervical
• 12 Thoracic
• 5 Lumbar
• 5 Sacral
• 1 Coccygeal

Question 2

How many spinal cord segments are there?

Answer 2

• 31
• 8 Cervical
• 12 thoracic
• 5 Lumbar
• 5 Sacral
• 1 Coccygeal

Question 3

Where does the C1 nerve emerge?

Answer 3

between base of skull and C1 vertebra

Question 4

Where do nerves C2-C7 emerge?

Answer 4

Superior to their numbered pedicles

Question 5

Where does C8 emerge from?

Answer 5

Inferior to pedicle of Cervical vertebra 7

Question 6

Where to nerve T1-Co1 emerge?

Answer 6

Inferior to their numbered pedicles

Question 7

What are the names of the 2 enlargements of the spinal cord?

Answer 7

• Cervical enlargement (for brachial plexus)

- Lumbar enlargement (Sciatic nerve)

Question 8

What are the 2 structures formed by extensions of the pia matter?

Answer 8

• Denticulate ligaments

- Filum Terminale

Question 9

What is the Dura and bone separated by?

Answer 9

Fat filled epidural space

Question 10

How does the dura surrounding the cord differ from that surrounding the brain?

Answer 10

One one layer thick (meningeal) as periosteal layer surrounding brain becomes periosteum of the skull

Question 11

How are the dura and arachnoid matter separated?

Answer 11

Subdural space (potential space)

Question 12

What is the termination of the spinal cord known as?

Answer 12

Conus Medullaris

Question 13

What makes up the Cauda Equina?

Answer 13

Dorsal & ventral roots of lower lumbar, sacral & coccygeal segmental spinal nerves

Question 14

How does the spinal cord change in length with age?

Answer 14

• Foetus= Spinal cord & dura terminate at end of vertebral column
• Birth= Filum terminale extends to Co1, spinal cord terminates at L3
• Adult=Spinal cord terminates at L1, Dural sac subarachnoid space termination S2

Question 15

Describe the arterial supply of the spinal cord

Answer 15

-Arterial blood via unpaired anterior & paired posterior spinal arteries

Question 16

What do spinal arteries arise from?

Answer 16

Vertebral arteries

Question 17

What are the vertebral arteries supported by in the spinal cord?

Answer 17

Segmental medullary & radicular arteries along the length of the cord

Question 18

Where do the spinal branches arise in different levels of the body?

Answer 18

• Vertebral= neck
• Posterior intercostal= thorax
• Lumbar= abdomen
• Lateral sacral= pelvis

Question 19

What type of nerve fibres are carried in the dorsal grey horn of the spinal cord?

Answer 19

-Somatic & visceral sensory

Question 20

What is contained within the dorsal root of the spinal cord?

Answer 20

• Dorsal root ganglion

- Somatic & visceral sensory fibres

Question 21

What type of nerve fibres are carried in the ventral grey horn of the spinal cord?

Answer 21

• Somatic motor

- Visceral motor

Question 22

What nerve fibres are contained within the spinal nerve?

Answer 22

Mixed: Somatic & visceral motor and Somatic & visceral sensory

Question 23

What does each spinal nerve take as it leaves the vertebral canal? What does this become?

Answer 23

• Meningeal coverings

- Form the Epineurium (protective outer sheath of connective tissue)

Question 24

What is the variation in white matter?

Answer 24

-White matter inc as ascend cord

Question 25

Where does the ventral grey horn enlarge?

Answer 25

Where motor fibres to limbs arise (cervical & lumbar enlargements)

Question 26

What are the 2 columns of each side of the midline of the cord? Where are they located?

Answer 26

- Gracile fascicle medially - Cuneate fascicle laterally - Above segment T6

Question 27

Where are the following located and what are there functions: - Dorsal column - Lateral corticospinal tract - Ventral corticospinal tract - Spinothalamic tract

Answer 27

- DC: right, ipsilateral joint position sense & vibration sense - LCT: Voluntary movement on right (located on right of spinal cord) - VCT: Voluntary movement on right (located on left of spinal cord) - ST: Contralateral pain, light touch & temp (located on left of spinal cord)

Question 28

What is the functional difference between dorsal &ventral nerve roots?

Answer 28

``` Dorsal = Sensory Ventral = Motor ```

Question 29

What conditions would you obtain a sample of CSF for?

Answer 29

- Meningitis - Subarachnoid haemorrhage - Guillain-Barré Syndrome

Question 30

Starting from the skin list the layers pierced when doing a lumbar puncture

Answer 30

- Skin - Fat - Supraspinous ligament - Interspinous ligament - Dura mater - Arachnoid mater

Question 31

Which spinal cord segment has the most white matter? Why?

Answer 31

- Cervical segment | - All fibres from the whole body travel in the cervical spinal cord

Question 32

What information is carried in the sections of the dorsal white matter?

Answer 32

- (medial) fasciculus gracilis= fibres from lower limb | - (lateral) fasciculus cuneatus= fibres from upper limb

Question 33

What are the inferior & superior boundaries of the epidural space?

Answer 33

Superiorly=Foramen Magnum | Inferiorly= Tip of sacrum at sacrococcygeal membrane

Question 34

What are the clinical presentations of a nerve compression between L5 & the sacrum?

Answer 34

- Sciatica | - Weakness in dorsiflexion= foot drop