Spinal Cord White Matter: pgs 26-27

Question 1

What are the pyramidal descending UMN system motor tracts that are pyramidal?

Answer 1

Lateral corticospinal tract

Ventral corticospinal tract

Question 2

What are the pyramidal descending UMN system motor tracts that are extrapyramidal?

Answer 2

Rubrospinal tract
Lateral vestibulospinal tract
Medial vestibulospinal tract
Reticulospinal UMN tracts

Question 3

What are the ascending sensory tracts?

Answer 3

Lateral spinothalamic tracts
Fasciculus gracilis
Fasciculus cuneatus
Dorsal Spinocerebellar tract

Question 4

What is the function of the Reticulospinal UMN tract?

Answer 4

Fibers from the primitive reticular formation of the brainstem that descend and synapse on or near LMNs in the spinal cord

Question 5

What is the function of the Lateral corticospinal tract?

Answer 5

Fibers from cell bodies in the cerebral cortex that descend, cross, and synapse on and control activity of LMN in the spinal cord. Specialized for movement of the distal extremities

Question 6

What is the function of the medial vestibulospinal tract??

Answer 6

Fibers from the cell bodies in the vestibular nucleus in the medulla that descend and synapse on or near LMNs to control activity of LMNs on both sides of the spinal cord. Its involved in movements that help regain balance when falling.

Question 7

What is the function of the ventral corticospinal tract?

Answer 7

Fbers from cell bodiesi n the cerebral cortex that descend and synapse on and control activity of LMNs in the spinal cord. They have a minor role in the movements of the trunk

Question 8

What is the function of the lateral vistibulospinal tract?

Answer 8

Fibers from the cell bodies in the vestibular nucleus primarily in medulla that descends and controls activity of LMNs in the spinal cord. It plays a role in maintaining upright posture.

Question 9

What is the function of the rubrospinal tract?

Answer 9

Fibers from cell bodies in the red nucleus of the midbrain that cross and descend to synapse on LMNs in the spinal cord. Minor role in control of extremities

Question 10

What is the function of the lateral spinothalamic tract?

Answer 10

Fibers from cell bodies in the spinal cord gray (nucleus proprius) that cross to the other side of the SC, and ascend, transmitting pain and temperature sensation to the thalamus. Part of anterolateral system which includes other parallel tracts

Question 11

What is the function of fasciculus gracilis?

Answer 11

Fibers from cell bodies in the DRG that ascend and transmit two point tactile discrimination, conscious proprioception and vibration sense from the lower half of the body (T7 and below) to nucleus gracilis in the medulla. Part of the dorsal white columns

Question 12

What is the function of fasciculus cuneatus?

Answer 12

Fibers from cell bodies in the DRG that ascend and transmit two point tactile discrimination, conscious proprioception and vibration sense from the upper body (T6 and above) to nucleaus cuneatus in the medulla. Part of the dorsal white columns.

Question 13

What is the function of the dorsal spinocerebellar tract?

Answer 13

Fibers from cell bodies in nucleus dorsalis in the spinal cord that transmit nonconscious proprioception to the cerebellum (one of several cerebellar tracts)

Question 14

Functional groupings of fibers within the columns are called _______ or _________.

Answer 14

Tracts or fasciculi

Question 15

Axons cross (decussate) from one side of the spinal cord to the other by the tiny bridge, the _______________________________.

Answer 15

Anterior white commissure