Spinal cord anatomy

Question 1

What is the conus medullaris?

Answer 1

The tapered end of the spinal cord (L1/2)

Question 2

What is the filun terminale?

Answer 2

Delicate strands of fibrous tissue preceding down from the apex of conus medullaris

Question 3

What is the cauda equina?

Answer 3

Lumbosacral nerve roots surrounding the filum terminale to for a cluster

Question 4

What are the layers of the meninges?

Answer 4

From out to in:
Dura mater
Arachnoid
Pia mater

Between arachnoid and pia mater is the subarachnoid space where cerebrospinal fluid circulates

Question 5

What are the different classifications of reflexes?

Answer 5

Monosynaptic/Polysynaptic
Ipsilateral/Contralateral
Intrasegmental/Intersegmental

Question 6

Describe a flexor withdrawal reflex

Answer 6

Stimuli applied to skin, stimulating free nerve endings. Fibres make polysynaptic connections with excitatory interneurons, resulting in ipsilateral flexor muscles contracting and extensors relaxing allows limb to move away

Question 7

Describe a crossed extensor reflex

Answer 7

Stimuli activated pain fibres. Afferent fibres send collaterals through anterior commissure to alpha motor neurones innervating contralateral flexors and extensors causing contraction of contralateral extensors and relaxation of flexors, permitting the withdrawal of ipsilateral limb