Week 4 Vocab

Question 1

Posterior column medial lemniscal system

Answer 1

a long sensory tract of the nervous system functioning to carry information about vibration, joint position, and fine touch

Question 2

Anterolateral systems

Answer 2

a long sensory pathway containing several tracts of the nervous system functioning to carry information about pain, temperature, and crude touch

Question 3

Somatosensory

Answer 3

refers to bodily sensation of touch, pain, temperature, vibration, and proprioception

Question 4

Dorsal root ganglia

Answer 4

location for sensory neuron cell bodies

Question 5

Dermatome

Answer 5

a peripheral region innervated by sensory fibers from a single nerve root

Question 6

Fasciculus gracilis

Answer 6

-the medial portion of the posterior column of the spinal cord.

Question 7

Fasciculus cuneatus

Answer 7

-the lateral portion of the posterior column of the spinal cord

Question 8

Ventral posterior lateral nucleus

Answer 8

-part of the lateral nuclear group of the thalami where both second order neurons synapse for the two long sensory tracts

Question 9

Spinothalamic tract-

Answer 9

part of the ALS pathway and the tract that mediates discriminative aspects of pain and temperature; like the PCML, this tract comes from the periphery, travels to the VPL of the thalamus and synapses on the primary somatosensory cortex

Question 10

Spinomesencephalic tract

Answer 10

-part of the ALS pathway and the tract that assists with pain modulation, this tract projects to the midbrain periaqueductal gray matter and the superior colliculi

Question 11

Spinoreticular tract

Answer 11

-part of the ALS pathway and the tract that is responsible for the emotional arousal of the pain sensation; this tract terminates on the medullary-pontine formation

Question 12

Primary somatosensory cortex.

Answer 12

-post central gyrus, Brodmann’s areas 3, 1, and 2

Question 13

Paresthesias

Answer 13

-abnormal positive sensory phenomena

Question 14

Transverse cord lesion

Answer 14

-a lesion to the spinal cord resulting in all sensory and motor pathways being partially or completely interrupted

Question 15

Central cord syndrome

Answer 15

-in small lesions there is damage to the spinothalamic fibers crossing the ventral/anterior commissure and causes bilateral region of sensory loss to pain and temperature; with larger central cord lesions the anterior horn cells are damage, and this produces lower motor neuron deficits at the level of the lesion; if the corticospinal tracts are affected, this will cause UMN signs and posterior columns can also be involved

Question 15

Hemicord lesions

Answer 15

-also known as Brown-Sequard Syndrome-damage to the spinal cord such that the corticospinal tract is deficient and causes ipsilateral UMN type weakness, the PCML tract is deficient and causes ipsilateral loss of vibration and joint position sense, and the ALS pathway is deficient and causes contralateral loss of pain and temperature sensation

Question 16

Posterior cord syndrome

Answer 16

-lesions to the posterior columns cause loss of vibration and position sense below the level of the lesion

Question 17

Anterior cord syndrome

Answer 17

-lesions to the anterolateral pathways causes loss of pain and temperature sensation below the level of the lesion, and damage to the anterior horn cells produces lower motor neuron weakness at the level of the lesion; with larger lesions the lateral corticospinal tracts may be involved causing UMN