2pt Tactile & Propioception - S

Question 1

What does crude tactile information encompass? Which tract does crude tactile information ascend in? Does it persist after lesions of the posterior columns? What R’s are involved? Where along this path would a lesion produce sx (and what sx)?

Answer 1

Passive touch (grabbing a door handle)
VSTT (ventral spinothalamic tract)
Yes, as it does not travel here
Bare n endings, Merkel’s tactile disks

At the spinal lemniscus in the medulla, it would produce contralateral hemianalgesia and thermal hemianestesia

Question 2

What encompasses active touch? What’s special about this sensory system? What lesion would interrupt this pathway? What R’s convey initial information?

Answer 2

Refined and precise touch info, vibratory into

It’s the fastest direct line sensory system in the body

A lesion of the posterior columns

Bare n endings and Pacinian corpuscles (pressure)

Question 3

Name the spinocerebellar pathways (unconscious cerebellar modalities) that fall under precise and gross propioception. Where do these tracts end in the brain?

Answer 3

Precise: dorsal spinocerebellar tract (DSCT)(LEs), cuneocerebellar tract (UEs)

Gross: ventral spinocerebellar (VSCT)(LEs), rostral spinocerebellar tract (UEs)

Cerebellar cortex of vermis

Question 4

Draw the crude tactile pathway.

Answer 4

See notes

Question 5

Draw the precise propioception/2pt pathway.

Answer 5

See notes

Question 6

What is the importance of tactile and proprioception?

Answer 6

Both provide necessary, extremely accurate sensory input that helps the motor system position the body in space and in relation to other objects in an effective manner