Spinal Cord Function and Dysfunction Flashcards
What are the two enlargements in the spinal cord and what is their significance?
Cervical enlargement (C5-T2) – has extra motor neurons that go to the muscles of the upper limb Lumbosacral enlargement (L1-S2) – has extra motor neurons that go to the muscles of the lower limb
What are the little protrusion of pia mater around the spinal cord called?
Denticulate ligaments
Which space is present in the spinal meninges but not in the cranial meninges?
Epidural space – this can be used for injecting anaesthetics
What are the three most important tracts in spinal cord injury? State their roles.
Lateral corticospinal tract – fine motor movements
Dorsal columns – touch, pressure, vibration, proprioception
Spinothalamic tract – pain and temperature
What are the two stages of lateral corticospinal tract damage?
SPINAL SHOCK – you get loss of reflexes below the level of the lesion leading to flaccid paralysis. The limbs become floppy and there is little muscle tone
RETURN OF REFLEXES – you get hyperreflexia and spasticity. The patient experiences spontaneous muscle contraction and there is very high muscle tone – rigid paralysis
Where do the upper motor neurons within the lateral corticospinal tract decussate?
Pyramidal decussation in the medulla
If you have a unilateral lesion of the lateral corticospinal tract in the mid-thoracic region, where will the deficit be?
Ipsilateral – on the same side as the lesion because the fibres decussate at the pyramidal decussation in the medulla
Where do the sensory fibres of the dorsal columns decussate?
Sensory decussation in the medulla
How are pain neurons arranged differently to other sensory and motor neurons?
The first order neurons synapse in the dorsal horn and then the second order neuron crosses to the contralateral side immediately (at the level of the synapse with the first order neurone)
The second order neurons then ascend on the contralateral side
Where does spinal chord end
L1 at conus medullaris
What does spinal chord continue as past conus medullaris
Cauda equina
3 horns of spinal chord
Dorsal
Intermediate
Ventral
Effect of lesion above medulla
Contralateral motor and sensory deficits
Right hemisection damage of spinal chord
Right sided paralysis
Left sided loss of pain and temperature
Right sided loss of touch
What anchors spinal chord to coccyx
Filum terminale
