Organization of the spinal cord and the brainstem

Question 1

Brainstem:

Answer 1

Pons
Medulla
Midbrain

Question 2

T/F: Right thalamus will receive sensory information from the right side of the body?

Answer 2

False. The right thalamus will receive sensory information from the left side of the body

Question 3

Principle of 2nd order axons:

Answer 3

Axons of 2nd order neurons in sensory pathways crossover contralaterally

Question 4

How does somantosensory initially travel?

Answer 4

From the peripheral nerve fibers to the spinal cord then finally arriving at the CNS

Question 5

Sensory function Proprioception:

Answer 5

Receptor type: Muscle spindle

Question 6

Sensory function: Touch

Answer 6

Receptor type: Merkel, meissner, pacinian, and ruffini cells

Question 7

Sensory function: Pain, temperature

Answer 7

Receptor type: free nerve ending

Question 8

Where is the medial leminiscus located?

Answer 8

Inside the middle portion of the medulla

Question 9

Where is the Gracile nucleus located?

Answer 9

Inside the frontal portion of the medulla

Question 10

Where is the Cuneate nucleus located?

Answer 10

Inside the temporal portion of the medulla

Question 11

Spinal nerve:

Answer 11

Dorasal root (sensory)
Ventral root (motor)

Question 12

Spinal cord:

Answer 12

31 pairs of spinal nerves:
C=8
T=12
L=5
S=5
C=1

Question 13

Where does the spinal cord end?

Answer 13

Causally end between L1 and L2

Question 14

What spinal nerves are good for obtaining CSF and epidural injections?

Answer 14

Cauda Equina L2-S4. Only spinal nerves and no spinal cord tissue

Question 15

Anterolateral system (ALS):

Answer 15

Pain, temperature, and itch pathway

Question 16

Damage to the Lateral corticospinal tract:

Answer 16

Spastic paralysis, babinski sign, loss of motor movement

Question 17

Dorsal columns:

Answer 17

Touch and proprioception

Question 18

What are the lateral motor columns?

Answer 18

C5-T1
L1-S3

Question 19

Lateral motor column C5-T1:

Answer 19

Innervates muscles of the upper extremity

Question 20

Lateral motor column L1-S3:

Answer 20

Innervates muscles of the lower extremity

Question 21

Dorsal nucleus of Clarke:

Answer 21

Spinal level C8-L3
Nucleus of origin of the dorsal spinocerebellar

Question 22

Medial motor columns:

Answer 22

All levels; lower motor neurons innervating axial musculature

Question 23

Lateral motor columns:

Answer 23

C5-T1; lower motor neurons innervating muscles of the upper extremity

Question 24

Lesions in the rostral medulla, pons, midbrain, internal capsule (posterior limb) and cortex:

Answer 24

Will produce symptoms contralaterally

Question 25

Corticospinal tract:

Answer 25

-Originates from the primary cortex (precentral gyrus) (upper motor neurons) -Crosses at the level of caudal medulla - Lesions in the spinal cord causes ipsilateral (same side) symptoms: Spastic paralysis, Babinski sign

Question 26

Fas Cuneatus:

Answer 26

T6 and above; upper extremities

Question 27

Fas Gracilis:

Answer 27

Lower extremities

Question 28

Two point discrimination:

Answer 28

The ability of the brain to discern between two closely located touch like stimuli; the smaller the difference the larger the number of receptors

Question 29

T/F: Right thalamus receives sensory information from the left side of the body

Answer 29

True.

Question 30

Dorsal column medial lemniscal (DCML):

Answer 30

Touch pathway (non-painful)

Question 31

Where are the first neurons that synapse for DCML located?

Answer 31

First order neurons will synapse in the relay nuclei and have their cell bodies located in the dorsal root ganglion

Question 32

Where does decussation (cross over) occur in DCML?

Answer 32

2nd order neuron inside the caudal medulla

Question 33

2nd order neuron for DCML:

Answer 33

2nd order neuron will synapse in the VPL, will have their cell bodies located in the cuneatus and gracilis nuclei

Question 34

Lesions above the sensory decussation (above the 2nd order neuron) for DCML:

Answer 34

Loss of tactile (touch) non-painful sensations- contralateral

Question 35

Lesions at or below the spinal cord (above the 2nd order neuron) for DCML:

Answer 35

Loss of tactile (touch) sensations; non-painful; ipsilateral

Question 36

3rd order neurons for DCML:

Answer 36

Will synapse in the primary somatosensory cortex, and have their cell bodies in the VPL nucleus of the thalamus. Will terminate @ the cortex

Question 37

Where is decussation (crossing over) located for pain and temperature?

Answer 37

Contained within the spinal cord (ALS specific)

Question 38

What are some functions of the DCML system?

Answer 38

Morphosynthesis Graphesthesia Two-point discrimination Texture discrimination Vibration Proprioception

Question 39

Is DCML an ascending or descending pathway ?

Answer 39

Ascending pathway

Question 40

First order neurons for ALS:

Answer 40

1st order neurons that synapse in lamina I, II, or V will have their cell bodies in the dorsal root ganglion

Question 41

Second order neurons for ALS:

Answer 41

2nd order neurons that synapse in the VPL have their cell bodies in lamina I, II, or V

Question 42

Third order neurons for ALS:

Answer 42

3rd order neurons that synapse in somatosensory cortex, cell bodies in the VPL of the thalamus (termination)

Question 43

Where does decussation occur for ALS?

Answer 43

At the spinal cord

Question 44

Lesions for ALS:

Answer 44

At or below the spinal cord; ipsilateral Above the spinal cord; Contralateral loss of pain and temperature below the lesion after a few (2 or 3) spinal segments

Question 45

Horner's Syndrome:

Answer 45

-Miosis: Decreased pupillary size -Ptosis:Drooping of the upper eyelid -Anhidrosis: Decreased sweating of the ipsilateral face and neck -Loss of sympathetic innervation

Question 46

C fibers termination:

Answer 46

II, I

Question 47

A delta fibers termination:

Answer 47

I , V

Question 48

Spinothalamic tract neurons located in:

Answer 48

Lamina I, V

Question 49

Lamina neurons II:

Answer 49

Interneurons (excitatory or inhibitory) modulate transmission

Question 50

Where does the sensory information from the thalamus (pain, touch, and temp leave from

Answer 50

Leaves via thalamo-cortical projections; located in the posterior limb of the internal capsule

Question 51

Brown sequard syndrome:

Answer 51

-DCML lesion; touch and proproioception ipsilateral -ALS lesion; pain and temp contralateral -Corticalspinal tract lesion; Babinski sign and Spastic paralysis ipsilaterally. Loss of volitional control of movement ipsilaterally