Neuro L5

Question 1

Nucleus gracilus and nucleus cuneatus are collectively known as

Answer 1

Posterior column nuclei

Question 2

Somatosensory receptors detect these types of changes

Answer 2

mechanical
chemical
thermal

Question 3

All somatosensory receptors are this type of neuron

Answer 3

pseudounipolar

Question 4

All somatosensory receptors have

Answer 4

1: Cell body in DRG or CN ganglion
2: A central CNS process
3: Peripheral process ending in skin, muscle, or joint

Question 5

Cutaneous nerve endings are broadly divided into

Answer 5

Encapsulated

Nonencapsulated

Question 6

Temperature sensitivity is due to

Answer 6

channels that open within a specific range of temperatures

Question 7

Delta pain
Description
Myelination

Answer 7

Sharp, well localized, short duration

Carried by rapidly conducting myelinated fibers

Question 8

Slow pain
Description
Myelination

Answer 8

Poorly localized, aching

carried by unmyelinated fibers

Question 9

Three general types of ascending and descending pathways

Answer 9

1: Long ascending going to thalamus, cerebellum or various BS nuclei
2: Long descending going from cerebral cortex or BS nuclei to spinal cord gray
3: Short propriospinal fibers interconnecting spinal cord levels (coordinate flexor reflexes)

Question 10

Descending tracts are primarily located in

Answer 10

Anterior funiculi

Lateral funiculi

Question 11

Ascending tracts are primarily located in

Answer 11

Anterior funiculi
Lateral funiculi
Posterior funiculi

Question 12

Propriospinal tract

Description/location

Answer 12

propriospinal fibers surround spinal cord gray matter

Question 13

Discriminative touch is part of the _____ pathway located in ________

Answer 13

medial lemniscal pathway in the posterior column

Question 14

Discriminative touch pathway synapses in ______then ____ to form _______ then to ____ then terminates in _____

Answer 14

synapses in medulla then decussates to form medial lemniscus then to Ventral posterolater nucleus of lateral thalamus
Terminates in postcentral gyrus

Question 15

Posterior column is mostly

Answer 15

ascending large myelinated primary afferents from mechanoreceptors

Question 16

Spinal afferents have their cell bodies where

Answer 16

ipsilateral DRGs

Question 17

DRG rootlets enter cord fibers, divide into

Answer 17

Medial

Lateral

Question 18

Medial division
Myelination
diameter
path

Answer 18

Heavily myelinated
large diameter
enter posterior column and ascend to brainstem

Question 19

Lateral division
Myelination
diamter

Answer 19

finely myelinated and unmyelinated

small diameter

Question 20

Rostral to this vertebral level, few fibers are added to fasiculus _____ and fasiculus ____ starts to form

Answer 20

Rostral to T6
fasiculus gracilis
fasiculus cuneatus starts to form

Question 21

Fibers entering the posterior column are added ______ so sacral is most _____ and cervical is most______

Answer 21

added laterally
sacral is most medial
cervical is most lateral

Question 22

Second order fibers of Medial lemniscus pathway

path

Answer 22

cross midline in caudal medulla and form medial lemniscus

Question 23

Third order fibers path
Originate in
Go thru
Go to

Answer 23

Originate in thalamus (VPL)
asend thru internal capsule
synapse in primary somatosensory cortex in post central gyrus

Question 24

Posterior column-medial lemniscus system info is important for

Answer 24

conscious appreciation of 
touch
pressure
vibration
joint position/movement

Question 25

Injury of posterior column medial lemniscus system leads to

Answer 25

Ataxia (from proprioception) | impaired complex tactile discrimination

Question 26

Ability to discriminate complex shape of an object

Answer 26

sterognosis

Question 27

Spinothalamic tract/anterolateral pathway conveys ______ info

Answer 27

pain and temperature

Question 28

Spinothalamic tract/anterolateral pathway ends in

Answer 28

VPL of thalamus | or Reticular formation or limbic system to mediate pain responses (spinomesencephalic fibers go to PAG)

Question 29

Pain, temperature, and some mechanoreceptor fibers enter cord via project to Many synapse in

Answer 29

lateral division of dorsal root project to posterior horn many synapse in substantia gelatinosa

Question 30

In the anterolateral pathway, new fibers join at

Answer 30

anteromedial edge

Question 31

Somatotopic organization of anterolateral pathway

Answer 31

Caudal body parts: posterolateral | Rostral body parts: anteromedial

Question 32

Cortical areas involved in anterolateral pathway

Answer 32

widespread (postcentral gyrus, insula, others) reflects complex conscious awareness of pain

Question 33

Types of fibers in anterolateral pathway

Answer 33

Spinothalamic Spinoreticular Spinomesencephalic (spine, midbrain) Spinohypothalamic

Question 34

Spinoreticular fibers important for

Answer 34

changes in level of attention of pain response

Question 35

Spinomesencephalic fibers important for

Answer 35

pain control mechanisms

Question 36

Spinohypothalamic fibers important for

Answer 36

mediate autonomic response to pain

Question 37

damage to anterolateral pathway causes

Answer 37

Loss of pain and temperature sensations Loss of itch and tickle sensations Bowel, bladder pressure, sex sensations are saved because bilateral Tactile deficit is NOT noted because most are in posterior columns

Question 38

Primary somatosensory

Answer 38

postcentral gyrus

Question 39

Cordotomy

Answer 39

destroy spinothalamic tract to produce contralateral analgesia Cut lateral funiculus from dentiate ligament to ventral root Cut rostral to highest level of pain

Question 40

Three well characterized spinocerebellar tracts

Answer 40

Posterior spinocerebellar tract Anterior spinocerebellar tract Cuneocerebellar tract

Question 41

Posterior spinocerebellar tract conveys this info

Answer 41

ipsilateral proprioceptive leg

Question 42

Posterior spinocerebellar tract ascends this way thru ____

Answer 42

ipsilaterally through lateral funiculus

Question 43

Posterior spinocerebellar tract synapses in

Answer 43

clarkes nucleus

Question 44

Axons in the cuneocerebellar tract come from____, enter ______, synapse in____

Answer 44

cuneate nucleus enter inferior cerebellar peduncle synapse in vermis and cerebellar hemispheres

Question 45

Anterior spinocerebellar tract origin

Answer 45

Lateral surface of anterior horn at lumbar levels

Question 46

Anterior spinocerebellar tract is primarily concerned with _____

Answer 46

attempted movement of the leg (more complex than PSCT)

Question 47

Anterior spinocerebellar tract path

Answer 47

crosses midline twice so ultimately ipsilateral