Internal structure of spinal cord

Question 1

At what level does the spinal cord terminate

Answer 1

Between levels L1-L3

Spinal cord is not same length as vertebral column

Question 2

What is the filum terminale made of

Answer 2

Pial tissue–> it is a continuation of pia mater

Question 3

Describe the cauda equina

Answer 3

a collection of fibres that need to exit beloe the level of conus medullaris (SC termination)

Question 4

How many cervical, thoracic, lumbar, sacral and coccygeal nerves?

Answer 4

8 cervical
12 thoracic
5 lumbar
5 sacral
1 coccygeal

Question 5

What is the pyramidal decussation

Answer 5

Pyramids are part of medulla oblongata–> located on ventral surface of medulla
The decussation is the 85% of fibres of corticospinal tract that cross at the pyramids to the contralateral lateral corticospinal tract in white commisure
hence crossing of fibres at pyramids forms/is pyramidal decussation

Question 6

Where does the medulla transition into the SC

Answer 6

Foramen magnum

Question 7

Within what space does the SC lie

Answer 7

In subarachnoid space

Question 8

Approx diameter of SC

Answer 8

1cm diameter

Question 9

What are denticulate ligaments

Answer 9

Bands of pial tissue that extend out and attach to the spinal dura mater and arachnoid

Question 10

How many denticulate ligaments are there in the SC

Answer 10

Approx 21 pairs

Question 11

Function of denticulate ligaments

Answer 11

help anchor the SC to every intervertebral foramina

Question 12

Apart from filum and denticulate ligaments, what else anchors SC

Answer 12

Spinal nerve roots provide strongest anchorage and fixation of SC to VC