Spinal cord

Question 1

What is the spinal cord?

Answer 1

Extension of the CNS into the axial skeleton. Allows communication between the brain and body and local control of muscles.

Question 2

What are the functions of the spinal cord?

Answer 2

Transmit information, contain cell bodies of motor neurones, local processing of afferent and efferent information

Question 3

Define ‘meninges’

Answer 3

3 sheets of CT which envelope the brain and spinal cord. Pia mater, dura mater and arachnoid mater

Question 4

What are the functions of the meninges?

Answer 4

Physical support of the CNS, contain CSF, involved in CSF production/absorption

Question 5

Describe the histology of the dura

Answer 5

Dense collagen bundles, some fibroblasts, occasional blood vessels and sensory nerves

Question 6

Describe the histology of the arachnoid

Answer 6

Overlapping fibroblasts with a mesh of collagen fibres. Trabeculae connect to pia via collagen strands

Question 7

Describe the histology of the pia

Answer 7

Overlapping flattened fibroblasts, loose collagen network overlying the CNS

Question 8

Describe the gross structure of the meninges

Answer 8

Pia is closely applied to brain surface and spinal cord. It dips into nervous tissue with blood vessels to form the potential Virchow-Robin space which is continuous with the subarachnoid space. Fluid filled leptomeninges act as a shock absorbing cushion to protect the brain.

Question 9

What other structures do the meninges attach to?

Answer 9

Skull - dura contributes to inner periosteum (fuses meninges to calvarium) Dura is a free tube in the spinal column

Question 10

Where is the spinal cord tethered?

Answer 10

At both ends at the brain stem and filum terminal Along the length by nerve roots Supported by denticulate ligaments and CSF

Question 11

Where does the spinal cord terminate?

Answer 11

At the cauda equina

Question 12

What is the location of the cranial intumescence?

Answer 12

C6-T2. Supplies brachial plexus and thoracic limbs

Question 13

What is the location of the caudal intumescence?

Answer 13

L4-Cc5. Supplies lumbosacral plexus, pelvic limbs, sphincters and tail

Question 14

Describe arterial blood supply to the spinal cord

Answer 14

Question 15

What are the 3 vascular zones?

Answer 15

1. Inner vascular zone - vertical arteries only
2. Middle vascular zone - vertical and radial arteries
3. Outer vascular zone - radial arteries only

Question 16

Describe the venous drainage

Answer 16