Somatosensory Tract

Question 1

All the somatosensory tracts

Answer 1

General sensory pathway
Dorsal column - medial lemniscus pathway
Spinothalamic tracts
Spinocerebellar pathways
Ascending trigeminothalamic tracts

Question 2

Input of dorsal column

Answer 2

Pacini and Meissner corpuscles
Muscle spindles
Golgi tendons organ

Question 3

DORSAL CLOMUN NEURON INITIAL LOCATION

1. First order neuron
2. Second order neuron
3. Third order neuron

Answer 3

1. Dorsal root ganglion
2. Gracile and cuneate nuclei of medulla
3. VPL nucleus in thalamus

Question 4

DORSAL COLUMN

1. First order neuron
2. Second order neuron
3. Third order neuron

Answer 4

1. Give rise to fasciculus grasilis from lower extremities & fasciculus cuneatus from upper extremities
2. Give rise to internal arcuate fibres decussate in midline and form medial lemniscus
3. Project via internal capsule (post. limb) to primary somatosensory cortex

Question 5

Lesion in drosal column

Answer 5

Loss of ability to identify object by active touch of the hand without visual imput (astereogenesis)

Question 6

Dorsal column lesion

Answer 6

Ipsilateral loss of position and vibrator senses below level of lesion

Question 8

SPINOTHALAMIC TRACT

1. Ventral receive input from _______________ and carries ___________ sensation
2. Lateral receive input from ____________ and carries ___________ sensation

Answer 8

1. Free nerve endings and Merkle tactile disk, light and touch
2. Free nerve endings and thermal receptors, pain and temperature

Question 9

SPINOTHALAMIC TRACTS

1. First order neuron projects via ____________ to second order neuron.
2. In dorsal horn, second order neuron ____________________
3. Third order neuron project via _________________ to primary somatosensory cortex.

Answer 9

1. Dorsoateral tract of Lissaurer
2. Decussate in ventral white commissure
3. Posterior limb of internal capsule

Question 10

Unilateral lesion in spinal cord of lateral spinothalamic tracts results in?

Answer 10

Contralateral loss of pain and temperature sensation

Question 11

Function of ascending trigeminothalamic tracts.

Destination

If lesion occured?

Answer 11

Carry GSA (general somatic afferent) from face.

Primary somatosensory cortex (face area)

Loss of face sensation

Question 12

SPINOCEREBELLAR PATHWAY

1. Dorsal and ventral tracts carry input from________________.
2. Cuneocerebellar carry input from ___________.

Answer 12

1. Lower extremities and lower trunk.

2. Upper extremities and upper trunk.