M2-C2-Review For Somatic Sensory Systems Ii

Front 1

List the four fibers of the Spinothalamic tract.

Back 1

1. Spinohypothalamic fibers
2. Spinoreticular fibers
3. Spinothalamic fibers
4. Spinotectal (or Spinomesencephalic) fibers

Front 2

Where does the spinotectal (or spinomesencephalic) fibers go?

Back 2

Superior Colliculus

and

Periaqueductal Gray (PAG)

Front 3

What are the sensations conveyed by the spinothalamic tract.

Back 3

1. Crude touch
2. Pain
3. Temperature
4. Sexual/Pressure (conducted bilaterally from pelvic region and includes bowel/bladder)

Front 4

In the STT, what are the three nuclei regions where the axon collaterals, entering the dorsal horn, synapse with the projection neurons?

Back 4

1. Posteromarginal Nucleus
2. Nucleus Propius
3. Substantia Gelatinosa

Front 5

In the STT, for each segment, the projection axons decussate where? and form into what?

Back 5

Ventral White Commissure

(Contralateral) Spinothalamic Tract

Front 6

The neospinothalamic tract projects to what two nuclei in the thalamus?

Back 6

1. VPL (ventral posterolateral)

2. PO (Posterior Nucleur Complex)

Front 7

What does the VPL axons of the neospinothalamic tract pass through? and where does it end up?

Back 7

Posterior limb of the Internal Capsule

Area SI and SII

Front 8

Where does the PO axons of the neospinothalamic tract go to?

Back 8

Area SII and adjacent insular areas.

Front 9

What are the specific functions of the neospinothalamic tract?

Back 9

Crude touch

Fast Pain

Front 10

In terms of fast, well-localized pain, what is the function of VPL and PO of the neospinothalamic tract?

Back 10

VPL (with Area SI) - localizes the fast pain

PO (with Areas SII) perceives it

Front 11

The paleospinothalamic tract projects to what four nuclei in the thalamus?

Back 11

1. Nonspecific (intralaminar) thalamic nuclei
2. Brainstem Reticular Formation
3. Tectum & Periaqueductal Gray (PAG)
4. Hypothalamus

Front 12

What does the Ascending Reticular Activating System (ARAS) modulate?

Back 12

Consciousness that mediates the affective nature of somatic pain

& slow pain

Front 13

The RF (reticular formation) receives sensory input from what?

Back 13

All Cranial Nerves

Spinothalamic Tract

Front 14

What is the seat of consciousness?

Back 14

Cerebral cortex

Front 15

For the ARAS, input to the RF goes where, then to where?

Back 15

Intralaminar Nuclei

Cerebral cortex

Front 16

Lesions to the midbrain level causes what?

Back 16

Coma

Front 17

Lesions to the midpontines causes what?

Back 17

Persistent wakefulness

Front 18

Projections to the Tectum are involved in what physiological function?

Back 18

Head and eye reflex

Front 19

Projections to the PAG are involved in what physiological function?

Back 19

Antinociceptive (pain inhibition)

Front 20

The nerve fibers in the PAG project to where? then where does that project to?

Back 20

1. Serotonergic (Raphe nuclei) and Noradrenergic nuclei of brainstem.

2. Dorsal horn (and mediates pain inhibition.

Front 21

Excitation of what interneurons will inhibit pain transmission?

Back 21

Enkephalinergic interneurons.

Front 22

STT axons project directly to and synapse in what regions?

Back 22

1. RF
2. Midbrain
3. Thalamus
4. Hypothalamus

Front 23

Traumatic legions of peripheral nerves destroy what?

Back 23

Both motor and sensory fibers of all types.

Front 24

Lesions of dorsal roots destroy only what?

Back 24

Sensory fibers

Front 25

Extramedullary lesions of the dorsal roots are likely to produce what?

Back 25

Pain with dermatomal distribution (radicular pain)

Front 26

Peripheral neuropathy often results in what?

Back 26

sensory losses with a glove and stocking distribution

Front 27

Lesions of the DCML above the sensory decussation causes what?

Back 27

Contralateral loss of epicritic sensation.

Front 28

Lesions of the DCML below the sensory decussation causes what?

Back 28

Ipsilateral loss of epicritic sensation.

Front 29

What happens to the protopathic senses in DCML lesions.

Back 29

They remain on the contralateral side.

Front 30

Lesions of DCML affecting the lower body (f. gracilis) causes what? x3

Back 30

Loss of epicritic sensation

Sensory ataxia & wide-based gait

Romberg's sign

Front 31

Severe bilateral epicritic deficit suggests what? x3

Back 31

1. Lesion in the dorsal funiculus

2. Lesion in the paracentral lobules

3. Tabes dorsalis - tertiary syphillis infection with degeneration of lumbosacral dorsal root ganglia.

Front 32

Lesions of DCML affecting the upper body (f. cuneatus) causes what? x4

Back 32

1. Loss of epicritic sensations
2. Ataxia
3. Asterognosis
4. Agraphesthesia

Front 33

Lesions of STT causes what symptoms?

Back 33

Analgesia
Athermia.

Front 34

Lesions of the STT manifest symptoms on which side of the body?

Back 34

Always contralateral

Front 35

Besides a lesion of the STT, athermia and analgesia may indicate what symptom.

Back 35

Anterior Cord Syndrome

Affects regions of anterior spinal artery

Front 36

Lesion of the ventral white commissure results in what syndrome? What are the symptoms?

Back 36

Central Cord Syndrome

Bilateral loss of pain and temp. slightly below the segmental level of the lesion.

Front 37

What are the symptoms of Brown-Sequard Syndrome? x3

Back 37

1. Ipsilateral loss of all sensation at the level of legion

2. Ipsilateral epicritic deficit below level of lesion

3. Contralateral protopathic deficit.

Front 38

Thalamic syndrome symptoms.

Back 38

1. Hemianasthesia
2. Sensory Ataxia
3. Thalamic Pain - slow burning pain elicited by touch (Dejerine-Roussy syndrome)

all contralateral

Front 39

Unilateral lesion of both tracts in pons or above causes what?

Back 39

Hemianesthesia

Front 40

Lesion in the Cerebral cortex leads to what symptom?

Back 40

Hemianasthesia with emphasis on loss of epicritic sensation.

Front 41

Segmental sensory loss with Pain and Parasthesia indicates a lesion where?

Back 41

Spinal nerve or DRG lesion

Front 42

Loss of ipsilatreral epicritic sensation, loss of contralateral protopathic, and motor loss indicates what?

Back 42

Spinal cord hemisection

Front 43

Loss of epicritic sensation with no protopathic deficit indicates what?

Back 43

Legion of DC or ML

Front 44

Bilateral epicritic defecit in legs indicate what? x3

Back 44

Legion of:

Fasciculus gracilis
Paracentral lobules
Tabes dorsalis

Front 45

Bilateral epicritic deficit in arms indicate what?

Back 45

Medial lemniscus legion

Front 46

Hemianasthesia indicates what? x5

Back 46

1. Lesion of Medial lemniscus
2. Lesion of STT
3. Lesion of posterior limb of internal capsule
4. Lesion of Postcentral gyrus
5. Lesion of Ventral Posterior nucleus

Front 47

Bilateral loss of pain and temperature with an upper and lower level indicate what?

Back 47

Lesion of ventral white commissure

Front 48

Bilateral loss of pain and temperature with an upper level as well as paresthesia/paralysis and bowel/bowel incontingencies indicate what?

Back 48

Anterior spinal cord syndrome