L9C: Ascending Pathways - Spinothalamic System

Question 1

What is the Spinothalamic System?

Answer 1

Relays information for conscious perception of pain, temperature and less discriminative tactile sensation (light touch, pressure)

Question 2

Where do first-order neurons of the spinothalamic system enter the spinal cord?

Answer 2

Through the dorsal roots of spinal nerves.

Question 3

Where do first-order neurons synapse?

Answer 3

In the dorsal gray horn of the SC.

Question 4

Where do second-order neurons cross to the opposite side?

Answer 4

They decussate in the ventral white commissure of the spinal cord.

Question 5

After crossing, where do second-order neurons ascend?

forming what?

Answer 5

In the ventrolateral white matter of the spinal cord, forming the spinothalamic tract.

Question 6

What is the destination of the second-order neurons?

Answer 6

The thalamus

Question 7

Where do third-order neurons go after the thalamus?

Answer 7

They project to the somatosensory cortex in the brain.

Question 8

What type of sensory information does the spinothalamic system carry?

Answer 8

Pain, temperature, and crude touch sensations.

Question 9

Where does decussation occur in this system compared to the medial lemniscus system?

Answer 9

It occurs in the spinal cord (ventral white commissure), not in the medulla.

Question 10

Medial Lemniscus System

Answer 10

Spinothalamic System