Ascending And Descending Tracts Of Spinal Cord

Question 1

Where only can you find the lateral horn?

Answer 1

Thoracic region

Question 2

What is in the lateral horn?

Answer 2

Preganglionic sympathetic neurons

Question 3

Which type of movement passes through dorsal medial meniscus?

Answer 3

Fine touch vibration

Proprioception

Question 4

1st order neurons- dcml?

Answer 4

Enter dorsal column same side within the fasciculata gracilis cuneatus

Fibres ascend uncrossed

Synapse on medulla

Question 5

What information does fasciculus cuneatus have?

Answer 5

Upper limb

Question 6

Dcml 2 neurons?

Answer 6

Cross in medulla and ascend to thalamus
Forming medial lemniscus

Then project from thalamus to somatosensory cortex

Question 7

Damage to dorsal column- lesion on one side of spinal cord?

Answer 7

E.g multiple sclerosis

Loss of tactile and proprioception on same side

Symptoms such as sensory ataxia- loss of coordination

Question 8

Clinical test for damage to dorsal column?

Answer 8

Romberg’ sign- severe swaying on standing with eyes closed feet together

Question 9

Spinothalamic tract is for?

Answer 9

Pain
Temperature
And course touch

Question 10

1st order neuron of spinothalamic?

Answer 10

Enter dorsal horm and form tract of lissauer.

Collateral branches given off at tip of dorsal horn, run up or down 1-2 spinal segments

Synapse in dorsal horn with second

Question 11

Spinothalamic second?

Answer 11

Cross in dorsal horn at each level

Ascend in aterolateral column to thalamus

Fibres from lower limb- lateral
Fibres from upper limb- medial

Then project from thalamus to somatosensory cortex

Question 12

Damage to anterolateral column?

Answer 12

Lesion on one side will result in loss of pain temp and course touch of opposite side

Question 13

Outer tract injury such as cord compression due to herniated disc?

Answer 13

Loss of lower limb pain

Question 14

Inner tract injury i.e grey matter tumour can result in?

Answer 14

Loss of upper limb pain

Question 15

Unconscious muscle proprioception is done by?

Answer 15

Spinocerebellar tracts for smooth motor coordination

Question 16

Which are the spinocerebellar tracts for trunk and lower limb?

Answer 16

Ventral and dorsal

Question 17

Which are the spinocerebellar tracts for upper limb?

Answer 17

Rostrum and cuneocerebellar

Question 18

Spinocerebellar tracts terminate in cerebellum at?

Answer 18

Same side

Question 19

Spinocerebellar tracts first order neurons?

Answer 19

Synapse in dorsal horn

Then ascend the lateral column to cerebellum, very fast axons

Question 20

Lesion on one side of spinal cord for dorsal spinocerebellar will result in?

Answer 20

Uncoordinated lower limb muscular activity on same side

Question 21

Pyramidal tract have 2 neurons?

Answer 21

Upper motor- from cerebral cortex to ventral horn

Lower motor- ventral horn to skeletal muscle

Question 22

Upper motor neuron journey?

Answer 22

Primary motor cortex to internal capsule to cerebral peduncle to pons to pyramid of medulla to lateral/anterior corticospinal tract

Question 23

Corticospinal tract fibres decimate at medulla so?

Answer 23

80% cross midline to form lateral

20% on same side - anterior corticospinal

Question 24

Lower motor organisation in ventral horn?

Answer 24

Medial -trunk
Anterolateral- proximal limb
Posterolateral - distal limb

Question 25

What causes motor neuron disease?

Answer 25

Disruption of corticospinal tract

Question 26

Upper motor neuron disease causes?

Answer 26

Spastic paralysis (increased muscle tone)

Overactive tendon reflexes

No signicant muscle atrophy

E,g following stoke

Question 27

If the upper motor neuron injury is above pyramids?

Answer 27

Then on opposite side

If below pyramids then same side

Question 28

If lower motor neuron injury in ventral horn or periphery then?

Answer 28

Flaccid paralysis
No tendon reflexes
Muscle atrophy

E.g spinal muscular atrophy
Guilin barre syndrome

Question 29

Amyotrophic lateral sclerosis?

Answer 29

Affects lower and upper motor neurons

Progressive muscle weakness and atrophy but mind intact

Symptoms in limbs or bulbar signs

Short life span for 5 days

Question 30

How many people affected by amyotrophic lateral sclerosis?

Answer 30

4-5 per 100,000

Question 31

Which are the extra pyramidal tracts?

Answer 31

Rubrospinal- red nucleus midbrain
Reticulospinal- reticular formation-pons
Vestibulospinal- vestibular nuclei in medulla

Question 32

Why are extrapyramidal tracts needed?

Answer 32

Maintaining posture and regulating involuntary movements

Question 33

Lesions to extrapyramidal tract cause?

Answer 33

Movement disorders ie. dyskinesia- involuntary muscle movement
Dystonia- involuntary muscle contractions