Session 3 - Spinal Afferent fibres

Question 1

Name five tracts of the spinal cord

Answer 1

Dorsal Column
Lateral spinothalamic 
Anterior spinothalamic
Anterior spinocerebellar
Posterior spinocerebellar

Question 2

What is the function of the dorsal column

Answer 2

Fine touch, vibration

Question 3

How many order neurones are there in the dorsal column tract?

Answer 3

Three

Question 4

What do first order neurones of the dorsal column have their cell body in?

Answer 4

Dorsal root ganglion

Question 5

Where do 2nd order neurone cell bodies of the dorsal column reside?

Answer 5

Cuneate (upper limb)/Gracile nucleus (lower limb)

Question 6

Where are the cell bodies of the third order neurones of the dorsal column?

Answer 6

Thalamus

Question 7

Where does the dorsal column decussate?

Answer 7

Medula

Question 8

Where does the dorsal column decussate?

Answer 8

Somatosensory cortex

Question 9

What is the function of the lateral spinothalamic tract?

Answer 9

Pain

Temperature

Question 10

Where is cell body of 1st order neurone of lateral spinothalamic tract

Answer 10

dorsal root ganglion

Question 11

Where is cell body of 2nd order neurone in lateral spinothalamic tract

Answer 11

Dorsal horn

Question 12

Where is cell body of third order neurone cell body of lateral spinothalamic tract

Answer 12

Thalamus

Question 13

Where does decussation of lateral spinothalamic tract take place

Answer 13

spinal cord

Question 14

Where does termination of lateral spinothalamic tract take place

Answer 14

Somatosensory cortex

Question 15

What is function of anterior spinothalamic tract?

Answer 15

Crude touch

Pressure

Question 16

1st order neurone cell body anterior spinothalamic tract?

Answer 16

Dorsal root ganglion

Question 17

2nd order neurone cell body anterior spinothalamic tract?

Answer 17

Dorsal horn

Question 18

3rd order neurone cell body anterior spinothalamic tract?

Answer 18

thalamus

Question 19

Decussation of anterior spinothalamic tract?

Answer 19

Spinal cord

Question 20

Termination of anterior spinothalamic tract?

Answer 20

Somatosensory cortex

Question 21

What is function of anterior spinocerebellar tract?

Answer 21

Unconscious proprioception

Question 22

1st order neuron cell body anterior spinocerebellar tract?

Answer 22

Dorsal root ganglion

Question 23

2nd order neuron cell body anterior spinocerebellar tract?

Answer 23

spinal grey matter

Question 24

3rd order neurone cell body of anterior spinocerebellar tract?

Answer 24

None

Question 25

Where is decussation of anterior spinocerebellar tract?

Answer 25

Spinal cord (re-crosses at superior cerebellar peduncle)

Question 26

Where is termination of anterior spinocerebellar tract??

Answer 26

Cerebellum

Question 27

Function of posterior spinocerebellar tract#;

Answer 27

Unconscious proprioception

Question 28

1st order neurone cell body anterior spinocerebellar tract?

Answer 28

Dorsal root ganglion

Question 29

2nd order neurone cell body

Answer 29

Cuneate nucleus

Question 30

Termination of anterior spinocerebellar tract?

Answer 30

Cerebellum

Question 31

What does vit b12 deficiency cause?

Answer 31

o Subacute Combined degeneration of dorsal column
Comes about secondary to alcohol addiction

Will have a o Stick and Stamp pattern of gait due to Sensory Ataxia – Loss of sensory input necessary for motor feedback

Question 32

What is syringomyelia?

Answer 32

o Repeated trauma to the neck (e.g. rugby) causes formation of Elongated Cavity or Syrinx around the Central Canal of the spinal cord.
o As it expands it compresses fibres, such as those of the spinothalamic tract which cross segmentally in the midline of the cord.

Question 33

What is Brown-Sequard Syndrome

Answer 33

o Lesion causing hemisection of the spinal cord
o All ascending pathways on one side of the cord are lost
o Fine touch and vibration lost below level of the lesion on the ipsilateral side
 Dorsal Columns travel up cord on ipsilateral side and decussate in the Ventral Medulla
o Pain, Temperature, Crude Touch lost below level of the lesion on the contralateral side
 Spinothalamic Tract decussates in the spinal cord, thus the lesion will effect fibres originating from the contralateral side