Somatosensory Pathways

Question 1

Which four sensory modalities does the Anterolateral Sytem relay?

Answer 1

Pain
Temperature
Non-discriminative touch
Pressure

Question 2

Which three sensory modalities do the Dorsal Columns relay?

Answer 2

Tactile sense
Vibratory sense
Positional sense

Question 3

Which sensory modalities do the somatosensory pathways to the cerebellum relay?

Answer 3

Proprioception

Question 4

Name the five Anterolateral systems?

Answer 4

Spinohypothalamic tract
Spinotectal tract 
Spinomesencephalic tract
Spinoreticular tract
Spinothalamic tract

Question 5

Name the two Dorsal columns?

Answer 5

Fasiculus Cuniatus - lateral

Fasiculus Gracilis - medial

Question 6

Name the three Somatosensory pathways to the cerebellum?

Answer 6

Rostral spinocerebellar tract
Posterior spinocerebellar tract - Ipsi-lateral
Anterior spinocerebellar tract - Contra-lateral

Question 7

Within the dorsal horn of the spinal cord, which laminae does Pain and Temperature synapse into?

Answer 7

Laminae I/II

Question 8

Within the dorsal horn of the spinal cord, which laminae does proprioception synapse into?

Answer 8

Laminae V

Question 9

Within the dorsal horn of the spinal cord, which laminae does mechanoreception synapse into?

Answer 9

Laminae III/IV

Question 10

Which tract does ‘conscious proprioception and fine touch’ ascend within and how does it travel?

Answer 10

Dorsal column - Ipsilateral

Question 11

Which tract does ‘pain and temperature’ ascend within and how does it travel?

Answer 11

Lateral spinothalamic tract - contralateral

Question 12

Which tract does ‘pressure and crude touch’ ascend within and how does it travel?

Answer 12

Anterior spinothalamic - contralateral

Question 13

How does the cerebellum receive Ipsilateral proprioception?

Answer 13

Fibres travelling ipsilaterally travel up the Posterior spinocerebellar tract
Fibres travelling contralaterally travel up the Anterior spinocerbellar tract and enter the cerebellum via the superior cerebellar peduncle.

Question 14

Which tract is affected by sensory ataxia?

Answer 14

Dorsal columns

Question 15

In sensory ataxia, the loss of concious proprioception leads to what symptoms?

Answer 15

Broad gait + stomping

Positive Rhomberg’s sign

Question 16

In sensory ataxia, the loss of fine touch leads to what symptoms?

Answer 16

loss of two-point discrimination

Question 17

Where does fine touch from the face go to?

Answer 17

Chief sensory nucleus of V passing contralateral beyond this point

Question 18

Where does pain and temperature from the head and neck go to?

Answer 18

Spinal nucleus of V (continuous with dorsal horn laminae I/II), it passes contralaterally beyond this point

Question 19

After fine touch fibres have crossed over inside the lower medulla, which fibre tract takes them to the thalamus?

Answer 19

Medial lemniscus

Question 20

How does the posterior spinocerebellar tract enter the cerebellum?

Answer 20

Via the inferior cerebellar peduncle

Question 21

Pain and temperature fibres from the thalamus go to which three places?

Answer 21

Insula
Primary somatosensory cortex (post-central gyrus)
Cingulate gyrus (limbic system)