Neuroanatomy - Ascending (sensory) Pathways

Question 1

Name the ascending pathways and their location in the spinal cord

Answer 1

Dorsal:
- Medial lemniscus
- Spinocerebellar
- Spino-olivary

Anterolateral:
- spinothalamic
- spinoreticular

Question 2

Describe the path of the medial lemniscus pathway

Answer 2

• dorsal
• gracile fasciculus originates in LL
• cuneate fasciculus originates in UL
• decussates in medulla
• terminates in somatosensory cortex (parietal)

Question 3

Describe the function of the medial lemniscus pathway

Answer 3

Conducts info of proprioceptive limb position, discriminative touch, pressure, vibration

Question 4

Describe the path of the spinocerebellar pathway

Answer 4

• dorsal
• no tertiary neurone
• terminates in cerebellum

Question 5

Describe the function of the spinocerebellar pathway

Answer 5

• conducts proprioceptive info to cerebellum
• posture and balance

Question 6

Describe the path of the spino-olivary pathway

Answer 6

• dorsal
• 3rd order neurone from olivary gland (medulla) to terminate in cerebellum
• ipsilateral because decussates twice

Question 7

Describe the function of the spino-olivary pathway

Answer 7

• conducts proprioceptive info to cerebellum
• posture and balance

Question 8

Describe the path of the spinothalamic pathway

Answer 8

• anterolateral
• anterior and lateral pathways
• decussates in spinal cord
• terminates in primary motor cortex (frontal)

Question 9

Describe the function of the spinothalamic pathway

Answer 9

• anterior: conducts crude touch & pressure info (mechanoreceptors)
• lateral: conducts nociception & temperature (nociceptors and thermoreceptors)

Question 10

Describe the path of the spinoreticular pathway

Answer 10

• anterolateral
• traverses reticular system in brain stem
• decussates in spinal cord
• terminates in somatosensory cortex (parietal)

Question 11

Describe the function of the spinoreticular pathway

Answer 11

• conducts non-specific pain/nociception info