Neuroscience Week 3: Ascending Spinal Tracts

Question 1

Key Ascending Spinal Cord Pathways

Answer 1

• Posterior column
• anterolateral system (spinothalamic tract)
• Spinocerebellar

Question 2

Posterior Column fiber size

Answer 2

Large sensory fibers

Question 3

Posterior Column Function

Answer 3

Proprioceptive sensation

• Vibration
• Two-point discrimination
• joint position information

Question 4

Posterior Column Course

Answer 4

Ipsilateral

Question 5

Posterior Column Divisions

Answer 5

At T6 Cuneate - (Arms)

Gracile - (Legs)

Question 6

Anterolateral system (spinothalamic tract) Fiber size

Answer 6

small fibers

Question 7

Anterolateral system (spinothalamic tract) Function

Answer 7

• Pain
• temperature
• itch

Question 8

Anterolateral system (spinothalamic tract) Course

Answer 8

• doesn’t just synapse in the thalamus but the hypothalamus and brainstem which is why it is referred to the anterolateral system
• contralateral ascension of the spinal cord

Question 9

Anterolateral system inner and outer

Answer 9

Inner - Arms

Outer - Legs

Question 10

Cervical Syringomyelia

Answer 10

Syrinx affects inner arm fibers first before leg fibers

Question 11

Anterolateral system lateral and anterior

Answer 11

Lateral - pain/temperature

Anterior - Tactile/pressure

Question 12

Spinocerebellar Tract Fiber Size

Answer 12

Large sensory fibers

Question 13

Spinocerebellar Tract Function

Answer 13

joint proprioception to cerebellum for coordination

Question 14

Spinocerebellar Tract Course

Question 15

What type of neurons are spinal sensory nerves?

Answer 15

Pseudounipolar because it passes peripherally to join the motor root and centrally to join the spinal cord

Question 16

Spinocerebellar tracts

Answer 16

Large sensory fibers

Question 17

Spinocerebellar tracts Function

Answer 17

Joint proprioception for coordination

Question 18

Cell bodies for spinal sensory fibers lie in

Answer 18

Dorsal root ganglia

Question 19

spinal sensory axons are?

Answer 19

Pseudounipolar

Question 20

Lissauer Tract

Answer 20

The entry zone for the anterolateral system fibers

Question 21

Ventral Commissure

Answer 21

site where anterolateral system fibers decussate within the spinal cord

Question 22

Posterior median septum

Answer 22

separates the bilateral sides of the posterior column

Question 23

Posterior Intermediate Septum

Answer 23

separates ipsilateral fasciculi