Block 5

Question 1

Dorsal Column Medial Lemniscus tract: Pathway and Function

Answer 1

Pathway;

• N1/N2 synapse in spinal cord
• N2 decussate in medulla
• N2 medial lemniscus pathway to thalamus
• N2/N3 synapse in thalamus
• N3 to cortex

Function;
(conscious)
- fine touch
- proprioception

Question 2

Spinothalamic tract: Pathway and Function

Answer 2

Pathway;

• N1/N2 synapse in spinal cord
• N2 decussates almost immediately (within 2 segments)
• N2 to thalamus
• N2/N3 synapse in thalamus
• N3 to cortex

Function;
(conscious)
- crude touch
- pain
- temperature

Question 3

Spinocerebellar tract: Pathway and Function

Answer 3

Pathway;

• N1/N2 synapse in spinal cord
• N2 to cerebellum (ipsilaterally)

Function;
- endogenous subconscious sensory information

Question 4

Spinotectal tract: Pathway and Function

Answer 4

Pathway;
- to superior colliculi

Function;
- reflex turning of head and eyes to cutaneous stimulation

Question 5

Spinoreticular tract: Pathway and Function

Answer 5

Pathway;
- to RAS

Function;
- arouses consciousness in response to cutaneous stimulation

Question 6

Spino-olivary tract: Pathway and Function

Answer 6

Pathway;
- accessory olivary nuclei to cerebrum

Function;
- coordination of movement and balance

Question 7

Lateral Corticospinal tract: Pathway and Function

Answer 7

Pathway;
- cortex > corticospinal and corticobulbar tracts > internal capsule > cerebral penduncles > medullary pyramids > decussate > contralateral anterior horn motor neurons

Function;

• voluntary skilled motor activity
• independent flexion of distal joints

Question 8

Rubrospinal tract: Pathway and Function

Answer 8

Pathway;
- red nucleus > decussation in mesencephalon > cervical cord segments

Function;
- control and coordination of movement (upper limb)

Question 9

Anterior Corticospinal tract: Pathway and Function

Answer 9

Pathway;
- cortex > corticospinal and corticobulbar tracts > internal capsule > cerebral penduncles > medullary pyramids > ipsilateral anterior horn motor neurons

Function;
- Movement of axial muscles

Question 10

Medial Vestibulospinal: Pathway and Function

Answer 10

Pathway;
- medial and inferior vestibular nuclei > cervical and upper thoracic spinal segments

Function;
- Positioning of head and neck

Question 11

Lateral Vestibulospinal: Pathway and Function

Answer 11

Pathway;
- lateral vestibular nucleus > all spinal cord segments

Function;

• balance
• responses to sudden postural changes

Question 12

Reticulospinal tract: Pathway and Function

Answer 12

Pathway;
- pontine and medullary reticular formation > all spinal cord segments

Function;
- automatic posture and gait movements

Question 13

Tectospinal tract: Pathway and Function

Answer 13

Pathway;

• superior colliculus of tectum > cervical spine
• decussates in midbrain

Function;

• orienting and flinching movements, ballistic reach and navigational movements
• coordinates head and eye movements