Descending and Ascending Pathways

Question 1

Lateral vestibulospinal tract

Answer 1

Descending
Medial motor system
Position head and neck; balance; extension legs
Lateral vestibular nucleus (pons) => medial intermediate zone and medial motor nuclei

Question 2

Rubrospinal tract

Answer 2

Descending
Lateral motor system
Functions uncertain in humans; flexion arms
Red nucleus (midbrain) => ventral tegmental decussatio (midbrain) => lateral intermediate zone and lateral motor nuclei

Question 3

Pontine reticulospinal tract

Answer 3

Descending
Medial motor system
Automatic posture and gait-related movements; extension arms/legs
Pontine reticular formation => medial intermediate zone and medial motor nuclei

Question 4

Posterior column-medial lemniscal pathway

Answer 4

Ascending
Sensory: vibration, joint position, fine touch
Primary sensory neuron => spinal cord => crosses over at the lower medulla => thalamus => primary somatosensory cortex

Question 5

Lateral corticospinal tract

Answer 5

Descending
Lateral motor system
Fine movements of contralateral limbs; flexion legs
Cortex => pyramidal decussatio => lateral intermediate zone and lateral motor nuclei

Question 6

Tectospinal tract

Answer 6

Descending
Medial motor system
Functions uncertain in humans
Superior colliculus (midbrain) => medial intermediate zone and medial motor nuclei

Question 7

Anterior corticospinal tract

Answer 7

Descending
Medial motor system
Bilateral axial and girdle muscles (trunk, head and shoulders)
Cortex => medial intermediate zone and medial motor nuclei

Question 8

Anterolateral pathways

Answer 8

Ascending
Sensory: pain, temperature, crude touch
Primary sensory neuron => crosses over at the anterior commissure (spinal cord) => thalamus => primary somatosensory cortex

Question 9

Medial vestibulospinal tract

Answer 9

Descending
Medial motor system
Positioning head and neck; balance; extension arms
Medial vestibular nucleus (rostral medulla) => medial intermediate zone and medial motor nuclei

Question 10

Medullary reticulospinal tract

Answer 10

Descending
Medial motor system
Automatic posture and gait-related movements; flexion arms/legs
Medullary reticular formation => medial intermediate zone and medial motor nuclei