Anatomy and Physiology XV

Question 1

Where do vertebral disc herniations typically occur?

Answer 1

Posterolaterally at L4-L5 or L5-S1 (p.427)

Question 2

To what vertebral level does the spinal cord extend in adults?

Answer 2

To the lower border of L1-L2 vertebrae (p.427)

Question 3

To what vertebral level does the subarachnoid space containing the CSF extend in adults?

Answer 3

Lower border of S2 vertebra (p.427)

Question 4

Where is a lumbar puncture usually performed?

Answer 4

Between L3-L4 or L4-L5 (p.427)

Question 5

What is the vertebral level of the cauda equina?

Answer 5

L4-L5 (p.427)

Question 6

What type of information is transmitted via the dorsal columns of the spinal cord (DCML pathway)?

Answer 6

Pressure, vibration, fine touch, proprioception (p.427)

Question 7

Name the two regions of the dorsal column tract?

Answer 7

Fasiculus cuneatus, faciculus gracilis (p.427)

Question 8

What is the difference in information transmitted via the fasiculus cuneatus vs. fasiculus gracilis?

Answer 8

Gracilis- more medial; lower body and legs; Cuneatus- more lateral; upper body and arms (p.427)

Question 9

Describe the layout of information in the lateral corticospinal tract.

Answer 9

Upper body/ arms is more medial; lower body/ legs is more lateral (p.427)

Question 10

What type of information is transmitted via the lateral corticospinal tracts?

Answer 10

Descending voluntary motor information (p.427)

Question 11

In what vertebral levels are the intermediate horn sympathetics located?

Answer 11

T1-L2/3 (p.427)

Question 12

What type of information is transmitted via the anterior spinothalamic tract?

Answer 12

Crude touch, pressure (p.427)

Question 13

Describe the layout of information in the anterior spinothalamic tract.

Answer 13

Cervical information is more medial to sacral information (p.427)

Question 14

Describe the location and path of the first order neuron in the dorsal column medial leminiscus pathway.

Answer 14

Sensory nerve ending –> cell body in dorsal root ganglion –> enters spinal cord, ascends ipsilaterally in dorsal column (p.428)

Question 15

Compare the types of information carried in the lateral spinothalamic tract to that carried in the anterior spinothalamic tract.

Answer 15

Lateral: pain, temperature; anterior: crude touch, pressure (p.428)

Question 16

Describe the location and path of the first order neuron in the spinothalamic tract pathway.

Answer 16

Sensory nerve endings (Adelta and C fibers) (with cell bodies in the dorsal root ganglion) –> Enters spinal cord (p.428)

Question 17

What is the difference in information passage between the lateral corticospinal tract and the DCML/spinothalamic tracts?

Answer 17

DCML/ Spinothalamic –> ascending information flow; Lateral corticospinal tract –> descending information flow (p.428)

Question 18

Describe the location and path of the first order neuron information flow in the lateral corticospinal tract.

Answer 18

UMN has a cell body in the primary motor cortex –> decends ipsilaterally through internal capsule until decussating at the caudal medulla (pyramidal decussation) –> descends contralaterally (p.428)

Question 19

Where is the first synapse in the DCML spinal pathway?

Answer 19

Ipsilateral nucleus cuneatus or gracilis (of the medulla) (p.428)

Question 20

Where is the first synapse in the Spinothalamic tract?

Answer 20

In the ipsilateral gray matter of the spinal cord (p.428)

Question 21

Where is the first synapse in the Lateral corticospinal tract?

Answer 21

In the cell body of the anterior horn of the spinal cord (p.428)

Question 22

Describe the location and path of the second order neuron in the DCML pathway.

Answer 22

Decussates in the medulla and ascends contralaterally in the medial lemniscus (p.428)

Question 23

Describe the location and path of the second order neuron in the spinothalamic tract pathway.

Answer 23

Decussates at the anterior white commissure and ascends contralaterally (p.428)

Question 24

Describe the location and path of the second order neuron in the lateral corticospinal tract pathway.

Answer 24

LMN leaves the spinal cord (p.428)

Question 25

Where is the second synapse in the DCML spinal pathway?

Answer 25

VPL of the thalamus (p.428)