Somatosensory 3

Question 1

What is the dorsal column pathway also called?

Answer 1

Medial Lemniscal Pathway

Question 2

The dorsal column pathway is responsible for

Answer 2

light touch and vibrations

Question 3

Where are the 3 neurons located in the dorsal column pathway, starting from the lower end of the body?

Answer 3

1. Dorsal root ganglia
2. Gracile nucleus
3. Ventral posterior lateral (VPL)

Question 4

Where are the 3 neurons located in the dorsal column pathway, starting from the upper end of the body?

Answer 4

1. Dorsal root ganglia
2. Cuneate nucleus
3. Ventral posterior lateral (VPL)

Question 5

The dorsal column pathway, for the lower part of the body, starts in the ___ spinal cord

Answer 5

Thoracic

Question 6

The dorsal column pathway, for the upper part of the body, starts in the ___ spinal cord

Answer 6

Cervical

Question 7

In the dorsal column pathway, where does information go after it leaves the VPL?

Answer 7

Primary somatic sensory cortex located within the post central gyrus in the parietal lobe

Question 8

What is the highest level of the cortex?

Answer 8

Parietal lobe

Question 9

How many lobes are there in the brain?

Answer 9

5
temporal, parietal, occipital, frontal, insula

Question 10

Where’s the gracilis located in the spinal cord?

Answer 10

medial T7 and below
Information goes from medial to lateral

Question 11

Where’s the cuneatus located in the spinal cord?

Answer 11

lateral T6 and above (C1)
Located more lateral to gracilis

Question 12

Once the neurons synapse in the gracile and cuneatus nucleus, what happens?

Answer 12

They cross over and decussate and go to the 3rd order neuron (VPL)

Question 13

What is this region?

Answer 13

Thalamus

Question 14

What is the 3 neuron pathway in the Trigenimothalamic pathway?

Answer 14

1. Trigeminal ganglial
2. Principle nucleus of trigeminal complex
3. Ventral posterior medial (VPM)

Question 15

Once information reaches the VPM in the Trigenimothalamic pathway, where does it go?

Answer 15

Post central gyrus in the parietal lobe

Question 16

Does information go through the spinal cord in the trigenimothalamic pathway?

Answer 16

No b/c it already passed it since this pathway is for head and neck

Question 17

The trigeminothalamic pathway is responsible for

Answer 17

light touch, proprioception and vibration

Question 18

The smaller the receptive field, the ___ innervation, the ___ neurons in the area, which ___ sensitivity

Answer 18

More
More
Increased

Question 19

Examples of highly sensitive, more innervated areas

Answer 19

Mouth, Hands, Face

Question 20

Describe plasticity. What’s an example with fingers and what happens to the dorsal surface?

Answer 20

The way the brain is able to make changes/adapt
- It maximizes your ability to do things

After amputation of a finger, those areas are unresponsive to stimuli, so the dorsal surface expands into the region that’s no longer responsive so the other areas of the finger become more sensitive b/c there’s more area allotted to them

Question 21

Does plasticity account for areas of overstimulation, amputation, or both?

Answer 21

Both

Question 22

What happens in areas of overstimulation?

Answer 22

Stimulation increases in the areas you mostly use (for ex certain fingers) and you loos stimulation in areas that you don’t use as often