Alternative Pathways of Pain and Temperature

Question 1

True or false: All fibers ascend in the anterolateral system originate and terminate in the lateral spinothalamic tract?

Answer 1

False, Some fibers that ascend in the anterolateral system originate and terminate differently than fibers of the lateral spinothalamic tract (ie: not all spinothalamic tract fibers terminate in the VPL nucleus of the thalamus

Question 2

What is the alternative pathway of the anterolateral system known as?

Answer 2

Medial (projecting) spinothalamic tract

Question 3

What does the medial spinothalamic tract include?

Answer 3

1) Fibers that terminate in other nuclei of the thalamus

2) Spinoreticular fibers that terminate in the brainstem reticular formation

Question 4

What do the fibers that terminate in other nuclei of the thalamus do for alternative pain and temperature pathways?

Answer 4

These nuclei connect to many areas of the cerebral cortex

Question 5

What is the brainstem reticular formation?

Answer 5

A diffuse network of nuclei in the brainstem that have direct and indirect connections with virtually all levels of the central nervous system including many areas of the cerebral cortex.

Question 6

What type of activities does the reticular formation influence?

Answer 6

Sleep cycles, pain/sensory perception, pain, movement, visceral activity, consciousness, etc.

Question 7

What do the alternative projections of the medial spinothalamic tract ultimately provide sensation for and through which areas of the brain?

Answer 7

Alternative projections of the medial spinothalamic tract ultimately prove for sensations of pain to influence many areas of the cerebral cortex including areas that influence emotions and behavior (limbic areas), sensory perception and levels of consciousness

Question 8

What type of pain is the medial spinothalamic tract convey?

Answer 8

Slow stage of the pain experience including diffuse poorly localized pain and emotional and autonomic changes

Question 9

True or false: Spinothalamic and spinreticular fibers only ascend the cord in the dorsolateral part of the spinal cord white matter?

Answer 9

False, most of the spinothalamic and spinoreticular fibers ascend the cord in the dorsolateral part of the spinal cord white matter but some fibers ascend the ipsilateral side of the spinal cord

Question 10

What is significant to know about the tractotomy?

Answer 10

Typically disrupts the spinothalamic tract but it is important to know that some pain fibers travel on the ipsilateral side of the cord and can cause pain to reoccur