Ascending and descending tracts

Question 1

Describe the order of neurons in the DCML

Answer 1

1st order - Receptor to Spinal cord to Caudal Medulla and synapse
2nd order - Synapses then Decussates in the medulla up to thalamus, synapse
3rd order - Thalamus to motor cortex

Question 2

Describe the order of neurons in the ALS

Answer 2

1st order - Receptor to Spinal cord then synapse
2nd order - Synapses then Decussates in the spinal cord, travels up to thalamus, synapse
- Spinoreticular in pons
- Spinomesencephalic in midbrain
- Spinothalamic up to thalamus
3rd order - Thalamus to motor cortex

Question 3

What is the position of upper and lower body tracts tracts in the Spinal Cord

Answer 3

DCML - ULLU

ALS - LUUL

Question 4

What is the position of upper and lower body tracts tracts in the Caudal and rostral medulla

Answer 4

DCML - UU -> Ventral -> LL

ALS -LUUL

Question 5

What is the position of upper and lower body tracts tracts in the pons and midbrain

Answer 5

DCML - LUUL

ALS - LUUL

Question 6

What is the position of upper and lower body tracts tracts in the cortex

Answer 6

DCML - ULLU

ALS - ULLU

Question 7

What happens to a the ascending tracts if there is a lesion at the Caudal medulla

Answer 7

DCML - Bilateral sensory loss

ALS - Contralateral loss

Question 8

What happens to a the ascending tracts if there is a lesion in the spinal cord

Answer 8

DCML - Ipsilateral sensory loss below the lesion

ALS - Hemi cord lesion - ipsilateral at level, contralateral below

Question 9

What happens to a the ascending tracts if there is a lesion in the
Rostral medulla, Pons, Midbrain, Cortex

Answer 9

DCML - Contralateral loss

ALS - Contralateral loss

Question 10

What information do the ascending tracts carry

Answer 10

DCML - Proprioception, Vibration, fine touch

ALS - Crude touch, pain, temperature

Question 11

Describe the Lateral corticospinal tract

Answer 11

Start: Motor Cortex
Decussate: Caudal Medulla, pyramidal decussation
End: Entire cord
Function: Voluntary limb movement

Question 12

Describe the Rubospinal tract

Answer 12

Start: Red nucleus of midbrain
Decussate: Immediately in ventral tegmental decussation of midbrain
End: Cervical spinal cord
Function: Fine control of upper limb

Question 13

Describe the Anterior corticospinal tract

Answer 13

Start: Motor cortex
Decussate: Bifurcates at the level in spinal cord
End: Mid thoracic cord
Function: Voluntary movement of bilateral axial and girdle muscles

Question 14

Describe the LVST

Answer 14

Start: Pons
Decussate: Descends ipsilaterally
End: Entire cord
Function: Balance

Question 15

Describe the MVST

Answer 15

Start: Medial Medulla
Decussate: One down and bifurcates immediately in medulla
End: Cervical spinal cord
Function: Involuntary head and neck control

Question 16

Describe the Tectospinal tract

Answer 16

Start: tectum of midbrain
Decussate: Immediately in dorsal tegmental decussation in midbrain
End: Cervical spinal cord
Function: Voluntary head and neck movement

Question 17

Describe the PRST

Answer 17

Start: Pons
Decussate: Descends ipsilaterally
End: Entire Cord
Function: Posture and gait

Question 18

Describe the MRST

Answer 18

Start: Medulla
Decussate: Descend ipsilaterally
End: Entire Cord
Function: Posture and gait

Question 19

Which tracts are medial

Answer 19

AVTR

Anterior corticospinal
Vestibulospinal
Tectospinal
Reticulospinal