Kaplan Videos

Question 1

Spinal tap location

Answer 1

between L3-L4 and L4-L5 because the conus medullaris (end of spinal cord) ends at L2 in adults

Question 2

Nine layers pierced by lumbar puncture needle

Answer 2

Skin, superficial fascia, deep fascia, supraspinous ligament, interlaminar space, ligamentum flavum, epidural space, dura, (“pop”), ARACHNOID MATER (last tissue pierced), subarachnoid space with CSF

Question 3

Motor origin

Answer 3

Ventral horn

Question 4

Sensory Origin

Answer 4

Dorsal horn

Question 5

Fibers in Dorsal Horn medial division, proprioception

Answer 5

1a, 1b fibers

Question 6

Fibers in Dorsal Horn medial division, touch

Answer 6

2, A-beta fibers

Question 7

Fibers in Dorsal Horn lateral division, sharp pain and cold

Answer 7

3, A-delta fibers

Question 8

Fibers in Dorsal Horn lateral division, dull pain and warmth

Answer 8

4, C fibers

Question 9

Motoneurons in Ventral Horn and what they innervate

Answer 9

Alpha MN innervate skeletal muscle NMJ.
Delta MN innervate skeletal muscle spindles.
(medial MN’s in ventral horn innervate proximal muscles. lateral MN’s innervate distal muscels).

Question 10

If UMN CST lesion is between the cerebral cortex and medulla above the pyramidal decussation, where will the spastic paresis be present?

If the lesion is below the medulla, where will the spastic paralysis be present?

If the lesion is a LMN lesion, where will the deficit be?

Answer 10

Spastic weakness below and CONTRALATERAL to the lesion.

Spastic weakness below and IPSILATERAL to the lesion.

FLACCID weakness ipsilateral to the skeletal muscle their axons innervate.

Question 11

Sensory system that controls: conscious proprioception, fine touch, vibration, pressure, 2-pt discrimination.

Answer 11

Dorsal column Pathway- Medal Lemniscal System

Question 12

Sensory system that controls: conscious proprioception, fine touch, vibration, pressure, 2-pt discrimination.

• Lesion: loss of senses __(above/below)__ lesion
• Site of lesion: _(affected/unaffected)__ side of body
• Location of decussation: (lesion above this is CL symptoms; below is ipsilateral symptoms)

Answer 12

Dorsal column Pathway - Medal Lemniscal System

• Lesion: loss of senses __ABOVE__ lesion
• Site of lesion: _AFFECTED__ side of body
• Location of decussation: (lesion above this is CL symptoms; below is ipsilateral symptoms)

Question 13

How to tell where the lesion of the dorsal column lies: Romberg test.

Answer 13

Decreased balance + eyes OPEN = cerebellar lesion.

Decreased balance + eyes CLOSED = DC-ML lesion (bc vision compensates for interrupted proprioceptive input from DC).

Question 14

Sensory system that controls: Anesthesia (loss of Pain and Temperature sensation)

Answer 14

Spinothalamic Pathway - Anterolateral System

Question 15

Sensory system that controls: Anesthesia (loss of Pain and Temperature sensation)

• Lesion: loss of senses __(above/below)__ lesion
• Site of lesion: _(affected/unaffected)__ side of body
• Location of decussation: (lesion above this is CL symptoms; below is ipsilateral symptoms)

Answer 15

• Lesion: loss of senses __1-2 segments BELOW and beyond__ the lesion
• Site of lesion: _AFFECTED__ side of body
• Location of decussation: in the Spinal cord, so always CL symptoms below the lesion. Tract intact rostral to the lesion

Question 16

Thalamic nucleus that Dorsal column Pathway - Medal Lemniscal System and Spinothalamic Pathway - Anterolateral System.

Answer 16

VPL

Question 17

Where does Spinothalamic Pathway - Anterolateral System travel?

Answer 17

Neuron 1: travels from receptor to DRG.
Neuron 2: DRG, enters SC, travels 1-2 segments up/down in Lissauer’s tract. Decussates in SC and continues up through Medulla to VPL in thalamus.
Neuron 3: VPL in Thalamus to post central gyrus

Question 18

What tract mainly carries unconscious proprioceptive input form muscle spindles and GTOs to cerebellum?

Answer 18

Spinocerebellar tract

a) the dorsal spinocerebellar tract
b) the cuneocerebellar tract

Question 19

the subsets of spinocerebellar tract

Answer 19

a) the dorsal spinocerebellar tract - from lower limb to externeal cuneate nucleus in BS
b) the cuneocerebellar tract - from upper limb to Clarke’s nucleus in SC

both pass through inferior cerebellar peduncle and then end, ipsilateral ascent the entire time

Question 20

reflex contraction of skeletal muscle - name the two neurons involved in efferent and afferent signals.

Answer 20

1a dorsal root

LMN (aka alpha motor neurons)

Question 21

UMN have what net effect on muscle stretch reflex?

Answer 21

inhibitory

Question 22

Dorsal roots for prop/touch

For Pain/temp

Answer 22

Proprioception/touch: 1a, 1b, A-beta

Pain and temp: A-delta and C

Question 23

Infant with gait ataxia, dysarthria, hand clumsiness, loss of position sense, imparied vibratory sensation, and loss of tendon reflexes.

Answer 23

Friedreich’s ataxia. Frataxin gene, chromosome 9

Question 24

Bilateral paralysis with suppressed reflexes

Poliomyelitis, Werdnig-Hoffman Disease, ALS, or ASA occlusion?

Answer 24

Poliomyelitis, Werdnig-Hoffman Disease (LMN lesion only; VH)

Question 25

Bilateral spastic weakness in LL, bilateral flaccid weakess in UL. Poliomyelitis, Werdnig-Hoffman Disease, ALS, or ASA occlusion?

Answer 25

ALS (UMN and LMN deficits - no sensory or bowel/bladder deficits

Question 26

Bilateral spastic weakness and bilateral loss of pain and temp. Poliomyelitis, Werdnig-Hoffman Disease, ALS, or ASA occlusion?

Answer 26

ASA occlusion (spares DC and Lissauer tract - STT)

Question 27

Bilateral flaccid weakness, hypotonia and tongue fasciculations Poliomyelitis, Werdnig-Hoffman Disease, ALS, or ASA occlusion?

Answer 27

Werdnig-Hoffman Disease (LMN lesion only; VH)

Question 28

Altered vibratory sense in LL, urine retention, pain, Romberg Tabes Dorsalis, Brown Sequard Syndrome, Syringomyelia, Subacute Combined Degeneration (Vit B12)

Answer 28

Tabes Dorsalis (tertiary syphilis to demyelination of DC)

Question 29

Bilateral loss of vibratory sense, bilateral spastic weakness. Tabes Dorsalis, Brown Sequard Syndrome, Syringomyelia, Subacute Combined Degeneration (Vit B12)

Answer 29

subacute combined degeneration (SCT, Lateral CST, DC)

Question 30

Bilateral loss of pain and temp initially, bilateral flaccid paralysis. Tabes Dorsalis, Brown Sequard Syndrome, Syringomyelia, Subacute Combined Degeneration (Vit B12)

Answer 30

syringomyelia (STT damaged (2nd order neurons) by syrinx expansion/anterior white commissure damage)

Question 31

Ipsilateral loss of vibratory sense, ipsilateral spastic weakness, contralateral loss of pain and temp Tabes Dorsalis, Brown Sequard Syndrome, Syringomyelia, Subacute Combined Degeneration (Vit B12)

Answer 31

Brown Sequard Syndrome