Spinal Nervous System

Question 1

Where does the dorsal column medial lemniscus pathway decussate?

Answer 1

dorsal aspect of medulla oblongata

Question 2

Where does the anterior spinothalamic pathway decussate?

Answer 2

level of spinal cord

Question 3

what is the pathway for the dorsal column medial lemniscus pathway?

Answer 3

dorsal root, spinal cord, medulla decussation, pons, thalamus, somatosensory cortex

Question 4

what is the pathway for anterior spinothalamic pathway?

Answer 4

dorsal root, spinal cord decussation, medulla, pons, thalamus, somatosensory cortex

Question 5

Describe the two pyramidal tracts

Answer 5

both involved in voluntary movement
lateral corticospinal;
-decussate at pyramids
-80% fibres in tract
anterior corticospinal;
-decussate at vertebral level
-20% of fibres

Question 6

List the extrapyramidal tracts and what they are involved in

Answer 6

rubrospinal, reticulospinal (one on each tracts (most lateral), olivospinal, vestibulospinal tracts (most anterior)
coordination of molvement, posture, and muscletone
involuntary

Question 7

if anterolateral column is compromised what function(s) are lost? explain reason with decussation

Answer 7

pain + temp + crude touch

crosses @ level of vertebrae if spinal cord is severed at any level will be compromised

Question 8

if dorsal column is compromised what function(s) are lost? explain reason with decussation

Answer 8

proprioception + fine touch + vibration

crosses @ medulla if spinal cord severed below medulla it will be fine

Question 9

Describe ipsilateral and contralateral loss of function if one side of the spinal cord is severed? what is this called?

Answer 9

browns sequard syndrome
ipsilateral (same side) = loss of proprioception fine touch and vibration
contralateral = loss of pain and temperature sensation

Question 10

rubrospinal tract origin and function

Answer 10

originates red nucleus
- upper limb control (mainly cervical)

Question 11

reticulospinal tract origin and function

Answer 11

originates pons and medulla reticular formation
- automatic movements and posture

Question 12

vestibulospinal tract origin and function

Answer 12

originates vestibular nuclei
- lower limb muscle tone for posture and balance

Question 13

tectospinal tract origin and function

Answer 13

originates midbrain colliculi
- automatic postural movements of head in response to visual and auditory stimuli.