Physiology Of Neuronal Tracts

Question 1

Fine touch, pressure are carried on which ascending tract

Answer 1

Dorsal coloumn

Question 2

Crude touch is carried on which ascending tract

Answer 2

Ventral spinothalamic tract

Question 3

Pain and temperature are Carried on which ascending tract

Answer 3

Lateral spinothalamic tract

Question 4

Where does dorsal coloumn cross to thw other side?

Answer 4

Medulla

Question 5

Where does spinothalamic tract (lateral and ventral) cross to the other side?

Answer 5

In the spina Cord

Question 6

Where does lateral corticospinal. Tract decussate?

Answer 6

Medulla

Question 7

Where does ventral corticospinal tract decussate?

Answer 7

In spinal cord

Question 8

What is the pathway of corticospinal tract

Answer 8

cortex > anterior 2/3 of posterior limb & genu of internal
capsule > Brain stem > upper medulla> forming pyramid
in lower medulla.

Question 9

• All cranial nerve nuclei receive bilateral fibers, except:

Answer 9

lower part of facial nerve nucleus & the part of hypoglossal nerve nucleus
supplying genoglossus muscle ( protrudes tongue anteriorly and deviate it to
the opposite side) which receive contralateral fibers only

Question 10

In brown sequard syndrome, what are the functions lost at the level of the lesion?

Answer 10

 Loss of all sensations in
corresponding dermatomes on the
same side.
 Motor affection =flaccid paralysis
(LMNL) and loss of all reflexes
mediated via the affected segments

Question 11

In brown sequard syndrome, what are the functions lost below the level of the lesion?

Answer 11

-Loss of fine touch, vibration and
pressure sensations and sense of
position ipsilaterally due to
interruption of the dorsal column
( crude touch decreased but not
lost)

-loss of pain and temperature
sensations contralaterally

= paralysis ipsilaterally (LL only or UL+LL depending on the level)