Blumenfeld Neuroanatomy 07: Somatosensory Pathways

Front 1

2 main somatosensory pathways

Back 1

dorsal column
anterolateral

Front 2

fine touch is carried by ___ pathway

Back 2

DC

Front 3

anterolateral pathway conducts ___ (3) modalities

Back 3

pain
temperature
crude touch

Front 4

in addition to fine touch, DCs carry ___ (2)

Back 4

vibration
proprioception

Front 5

1st order DC fibers from level ___ and up synapse in ___
below that, 1st order DC fibers synapse in ___

Back 5

T6
nucleus cuneatus
nucleus gracilis

Front 6

decussation of DC pathway is via ___ from ___

at level of ___, these become ___

Back 6

arcuate fibers
nucleus cuneatus + gracilis
rostral medulla
medial lemniscus

Front 7

at level of rostral medulla, medial lemniscus is oriented ___ly
at level of pons it is oriented ___ly
at level of midbrain it is oriented ___ly

Back 7

feet ventral, arms dorsal (parallel to dorsoventral axis)
feet lateral, arms medial (45 degrees to dorsoventral axis)
feet lateral, arms medial (45 degrees to dorsoventral axis)

Front 8

2nd order neurons of DC pathway synapse in ___

Back 8

VPLN of thalamus

Front 9

3rd order neurons of DC pathway run from ___ to ___ via ___ in the ___

Back 9

VPLN of thalamus
1' somatosensory cortex
thalamic somatosensory radiations
posterior limb of internal capsule

Front 10

3 lateral ascending SC pathways

Back 10

anterolateral system
dorsal spinocerebellar tract
ventral spinocerebellar tract

Front 11

3 tracts of anterolateral system

Back 11

ST
spinoreticular
spinomesencephalic

Front 12

because of ___, lesion in anterolateral system causes hypoesthesia at/above/below the level of the lesion

Back 12

fibers of anterior white commisure ascend 2 or 3 levels before entering contralateral anterolateral system
below

Front 13

2nd order neurons of ST tract synapse in ___

Back 13

VPLN of thalamus

Front 14

3rd order neurons of ST tract are located in ___
they synapse in ___ after going through ___ in ___

Back 14

VPLN of thalamus
1' somatosensory cortex
thalamic somatosensory radiations
posterior limb of internal capsule

Front 15

in addition to VPLN, ST tract projects to ___ (2) in thalamus

Back 15

intralaminar nuclei
mediodorsal nucleus

Front 16

unlike VPLN, intralaminar nuclei project to ___ of cortex

Back 16

all

Front 17

intralaminar and ___ ST projections, together with ___, are responsible for ___

Back 17

dorsomedial nucleus
spinoreticular tract
emotional + qualitative aspect of pain

Front 18

spinomesencephalic tract projcets to ___ in ___
this provides ___

Back 18

PAG
midbrain
pain modulation

Front 19

3 parts of thalamus

Back 19

anterior nuclear group
medial nuclear group
lateral nuclear group

Front 20

the 3 groups of the thalamus are separated by the ___

Back 20

internal medullary lamina

Front 21

___ of thalamus are functionally related to intralaminar nuclei
___ is a sheet on lateral aspect of thalamus

Back 21

midline thalamic nuclei
thalamic reticular nucleus

Front 22

3 kinds of thalamic nuclei
most thalamic nuclei are the ___ kind

Back 22

relay
intralaminar
reticular
relay

Front 23

3 relay nuclei which are not located in the lateral group

Back 23

anterior
mediodorsal
midline

Front 24

output from BG and cerebellum is relayed at ___ nucleus,
which projects to ___ (3)

Back 24

ventrolateral
motor cortex
premotor cortex
supplementary motor area

Front 25

output from mammilary body and hippocampal formation is relayed at ___ nucleus,
which projects to ___

Back 25

anterior
cingulate gyrus

Front 26

___ is a posterior relay nucleus which projects widely
___ is a medial one

Back 26

pulvinar
mediodorsal

Front 27

pulvinar receives input from ___ and projects to ___ (3)

Back 27

superior colliculus
parietal cortex
temporal cortex
occipital cortex

Front 28

mediodorsal nucleus receives ___ input from ___ and projects to ___

Back 28

cognitive
limbic system
frontal association cortex

Front 29

intralaminar nuclei receive input and send output to ___
they also do ___

Back 29

BG
ascending reticular activating system

Front 30

2 kinds of intralaminar nuclei

Back 30

rostral
caudal

Front 31

BG input to intralaminar nuclei is from ___

Back 31

globus pallidus

Front 32

___ is the only thalamic nucleus which does not project to cortex

Back 32

thalamic reticular nucleus

Front 33

thalamic reticular nucleus receives input from ___ (3) and projects to ___

Back 33

thalamus
RAS
basal forebrain
thalamus

Front 34

thalamic reticular nucleus is composed almost exclusively of ___

Back 34

GABAergic neurons

Front 35

complete hemisensory deficit can be caused by lesion in ___ (2)

Back 35

whole contralateral 1' somatosensory cortex
VPLN + VPMN of contralateral thalamus

Front 36

hemisensory deficit in face with contralateral hemisensory deficit in
arm + trunk + leg
can be caused by lesion in ___
modality affected in face is ___
modality affected in arm + trunk + leg is ___

Back 36

lateral pons ipsilateral to facial deficit
lateral medulla ipsilateral to facial deficit
trigeminothalamic
ST

Front 37

hemisensory deficit in arm + trunk + leg
can be caused by lesion in ___
modality affected is ___
structure affected is ___

Back 37

medial medulla
DC
medial lemniscus

Front 38

5 SC syndromes

Back 38

transverse cord
hemicord
central cord
posterior cord
anterior cord

Front 39

hemicord lesions cause ___

Back 39

Brown-Sequard syndrome

Front 40

Brown-Sequard syndrome has ___ ipsilateral to lesion at ___ level,
and ___ contralateral at ___ level

Back 40

DC hemisensory deficit
LMN deficit at level of lesion
level of lesion
ST
2--3 levels below lesion

Front 41

central cord lesion causes ___ if small and ___ (4) if large

Back 41

suspended bilateral ST sensory loss
bilateral ST sensory deficit
bilateral DC sensory deficit
bilateral CS deficit
sacral sparing

Front 42

sensation from rectum, bladder, urethra, and genitalia enters SC at levels ___
sensation is transmitted via ___ tract(s)

Back 42

S2--S4
anterolateral
DC

Front 43

voluntary control of pelvic floor muscles is via ___ cells at level ___

Back 43

anterior horn cells
S2--S4

Front 44

voluntary control of urethral + anal sphincters is via ___ cells at level ___

Back 44

sphincteromotor nucleus of Onuf
S2--S4

Front 45

pelvic PARA output is via ___ at level ___
pelvic SYM output is via ___ at level ___

Back 45

sacral PARA nuclei
S2--S4
IML columns
T11--L1

Front 46

for lesions to cause bladder/bowel/sexual symptoms, they must be ___

Back 46

b/l

Front 47

in detrusor reflex, relaxation of ___ causes ___,
which causes ___

Back 47

external urethral sphincter
relaxation of bladder neck
detrusor contractoin

Front 48

relaxation of bladder neck occurs via ___
activation of detrusor occurs via ___

Back 48

inhibition of SYM
activation of PARA

Front 49

in the urethral reflex,
cessation of urine flow causes ___,
which causes ___

Back 49

urethral sphincter contraction
detrusor relaxation

Front 50

lesions in frontal micturition-inhibition centers cause ___ with normal ___

Back 50

loss of voluntary control of urination
bladder function

Front 51

SC lesions below ___ and above ___ cause ___ at first, then ___

Back 51

pontine micturition center
S2
atonic bladder
spastic bladder

Front 52

atonic bladder causes ___ incontinence
spastic bladder causes ___ incontinence

Back 52

overflow
urge

Front 53

spastic bladder may include ___

Back 53

detrusor-sphincter dyssynergia

Front 54

peripheral bladder neuropathy or ___ lesion may cause ___ bladder
this may cause either ___ or ___ incontinence

Back 54

S2--S4 cord lesion
atonic
overflow
stress

Front 55

neurogenic bladder means ___

Back 55

bladder dysfunction caused by any central or peripheral nerve lesion

Front 56

internal anal sphincter is made of ___ and is innervated by ___ nerves

Back 56

smooth muscle
sacral PARA

Front 57

external anal sphincter is made of ___ and is innervated by ___ nerves from ___

Back 57

striated muscle
pelvic
Onuf's nucleus

Front 58

pelvic floor muscles are innervated by ___ nerves

Back 58

sacral anterior horn

Front 59

sensory input from rectum enters SC at ___

Back 59

S2--S4

Front 60

sensory input from genitalis enters SC at ___

Back 60

S2--S4

Front 61

thalamus is perfused by ___ (3)
occlusion of one of these typically causes ___

Back 61

lenticulostriate branches of MCA
thalamoperforator branches of PCA
anterior choroidal branch of ICA
lacunar infarct

Front 62

4 classes of primary sensory neuron, in decreasing order of axon diamter

of these, ___ are myelinated

Back 62

A-alpha

A-beta

A-delta

C

A alpha, beta, delta

Front 63

___ fibers project to DC

___ fibers project to ALS

Back 63

A-alpha, A-beta

A-delta, C

Front 64

2 receptors connected to A-alpha fibers

Back 64

muscle spindle

golgi tendon organ

Front 65

6 receptors connected to A-beta fibers

Back 65

muscle spindle

Meissner's corpuscle

Merkel receptor

Pacinian corpuscle

Ruffini ending

Hair receptor

Front 66

receptors connected to A-delta and C fibers

Back 66

none (bare ending)

Front 67

A-beta fibers synapse in lamina ___ aka ___

Back 67

IV

nucleus proprius

Front 68

A-delta fibers synapse in laminae ___

Back 68

I

II (a little)

V

Front 69

lamina I is aka ___

Back 69

marginal zone

Front 70

C fibers synapse in lamina ___

Back 70

II

Front 71

pain modulation fibers from PAG synapse in ___

Back 71

rostral ventral medulla

Front 72

2 RVM pain-modulatory pathways

Back 72

raphe nucleus magnus 5-HT

substance P

Front 73

substance P from RVM modulates pain by ___ing

Back 73

activating locus ceruleus, causing NE release at dorsal horn