Lecture 03 - Sensory systems of the brain

Question 1

name the 2 somatosensory pathways from the skin to cerebral cortex

Answer 1

1. Discriminative - medial lemniscal system or dorsal column

2. Non-discriminative - spinothalamic tract

Question 2

What are the 2 parts of the dorsal column/funiculi?

Answer 2

Gracile (inner) and cuneate (outer)

Question 3

where are the toes vs neck located in the dorsal column?

Answer 3

toes = on the baseline of the gracile (medial)
neck = outer line of the cuneate

Question 4

what are the areas of white matter in the spinal cord?

Answer 4

ventrile columns
lateral columns (motor info)
Dorsal column

Question 5

Where does info swap from L –> R in the pain and temp pathway?

Answer 5

Ant. commisor

Question 6

what is a convergence?

Answer 6

100’s of neurons that synapse onto one fibre

Question 7

Where does crossing over of info occur in the discriminative pathway?

Answer 7

Int. arcuate fibres

Question 8

Is the medial lemniscus a white or grey matter tract?

Answer 8

white

Question 9

where does the last neuron terminate in both pathways?

Answer 9

ventro-posterior nucleus in the thalamus

Question 10

where does the impulse travel after terminating in the ventro-posterior nucleus?

Answer 10

via the internal capsule to the primary sensory cortex (postcentral gyrus)

Question 11

where does the 1st order neuron terminate in the non-discriminative pathway?

Answer 11

dorsal horn of the spinal cord

Question 12

where does the 1st order neuron terminate in the discriminative pathway?

Answer 12

cuneate or graciles nucleus