3 - Somatosensory system 2 Flashcards Preview

Semester 5 - Neuro > 3 - Somatosensory system 2 > Flashcards

Flashcards in 3 - Somatosensory system 2 Deck (18):
1

Which arteries supply the dorsal column?

Posterior spinal arteries (x2)

2

Which artery supplies the majority of the spinal cord (except dorsal column) ?

Anterior spinal artery

3

What are the 2 main ascending sensory tracts of the somatosensory system?

1) Dorsal Column Medial Lemniscus pathway (DCML)
2) Spinothalamic pathway

4

Which somatic senses are transported via the DCML pathway?

- Light touch
- Vibration
- Proprioception
- 2-point discrimination

5

Which somatic senses are transported via the spinothalamic pathway?

- Pain
- Crude touch
- Temperature

6

Describe the path of the 1st order neurones of the DCML pathway:

From origin to medulla
up spinal cord ipsilateral to the side of origin

7

Describe the path of the 2nd order neurones of the DCML pathway:

From medulla to thalamus
Decussate at medulla

8

Describe the path of the 3rd order neurones of the DCML pathway:

From thalamus to post-central gyrus
via internal capsule

9

Where do the neurones of the DCML pathway decussate?

Medulla

10

If a 1st order neurone entered the DCML pathway from the hand, where would it lie in the spinal cord compared to a neurone from the foot?

More laterally
Cervical neurones lie most laterally, sacral lie most medially

11

Describe the path of the 1st order neurones of the spinothalamic pathway:

From origin, enters spinal cord and synapses a few levels above

12

Describe the path of the 2nd order neurones of the spinothalamic pathway:

From distal spinal cord, decussates immediately, ascends CONTRALATERAL to site of origin, to thalamus

13

Describe the path of the 3rd order neurones of the spinothalamic pathway:

From thalamus to post-central gyrus
via internal capsule

14

If a 1st order neurone entered the spinothalamic pathway from the hand, where would it lie in the spinal cord compared to a neurone from the foot?

More medially
Cervical neurones lie most medially, sacral lie most laterally

15

Which fibres carry pain?

C fibres

16

Which fibres carry mechanoreceptor impulses?

A fibres

17

If you bang your knee, why does rubbing it make it less painful?

Descending control of pain:
Rubbing
= activation of mechanoreceptors
= activated A fibres
= excite inhibitory enkephalinergic interneurones in spinal cord
= bind to u-opioid receptor
= inhibit spinothalamic tract

18

Name some causes of insensitivity to pain:

- Congenital insensitivity to pain
- Trauma
- Diabetes
- Chronic kidney disease
- Chronic liver disease
- Excessive alcohol intake
- Cancers
- Hypothyroidism
- Acromegaly
- Guillian-Barre syndrome
- Inf: Shingles, HIV, Lyme disease
- AI: RA, SLE
- Drugs: Chemotherapy, HIV tx