Post on 16-Nov-2014
1
ATLAS NEUROANATOMYSomatosensory System
•Dorsal Column-Medial Lemniscal System
Spinal Cord
Forebrain
Brainstem
Dr. Donald Wong
•Anterolateral System
•Trigeminal System
2
Dorsal Column-Medial Lemniscal System
Haines Atlas (7th) 8-4
•Discriminative (fine) Touch
•Position sense
•Vibratory sense
•2-point discrim.
•Stereognosis
Midbrain
Pons
Medulla
SpC
3
Haines Atlas (7th) 6-1
???
??? DC-ML
4
Haines Atlas (7th) 6-1
Dorsal Column: fasciculus gracilis
Sacral level DC-ML
5Haines Atlas (7th) 6-3
???
???
???
???
???
???
DC-ML
?
?
6Haines Atlas (7th) 6-3
Fasc. gracilis
Fasc. cuneatus
T4 level
T6 and above
Dorsal Columns
Dorsal root (medial): large dia.
DC-ML
uT
L
7
Haines Atlas (7th) 6-5
???
??
??
??
??
???
DC-ML
???
8
Haines Atlas (7th) 6-5
C1 level
FG
FC
FG
FC
CST fibers decussating
DC-ML
Post. Intermediate sulcus
9Haines Atlas (7th) 6-8
???
DC-ML
???
???
???
???
???
???
10Haines Atlas (7th) 6-8
Pyramidal decussation
DC-ML
Caudal Medulla: DCN / x- Pyr
GrNu
CuNu
CuFs
GrFs
DCN
11
Haines Atlas (7th) 6-9
???
???
??.
??.
???
DC-ML
???
12
Haines Atlas (7th) 6-9
Caudal/Mid Medulla: DCN
G. N. & fasc.
C.N.
C.N.
Medial lemniscus
DC-ML
Internal arcuate fibers
13Haines Atlas (7th) 6-11
??
??
??
???
??
??
???
????
DC-ML
14Haines Atlas (7th) 6-11
MLF
TST
ML
Rostral Medulla: XII n. nucleus/ Inf. Olive
arm
leg
ML somatotopy: “Man standing on top of pyramid”
XIIXII
DC-ML
15Haines Atlas (7th) 6-17
Lower pons: level of facial colliculus, VII n./nucleus
??
??
DC-ML
**
*
???
???
???
??
16Haines Atlas (7th) 6-17
Lower pons: level of facial colliculus, VII n./nucleus
arm
leg
DC-ML
**
*
Tegmentum
Base
MCP
ML
17
Haines Atlas (7th) 6-20
???
???
???
??
???
???
DC-ML
*
*
18
Haines Atlas (7th) 6-20
Rostral pons/Caudal midbrain: level of V n./ IV n. exits
V nerve
IV nerve
ML
arm
leg
DC-ML
*
*
19
Haines Atlas (7th) 6-22
???
???
??
???
??? ???
DC-ML
* *
*
???
???
???
???
20
Haines Atlas (7th) 6-22
Caudal midbrain: Level of Inf. Colliculus
Rostral pons
ML
arm
leg X SCP
DC-ML
* *
*
Crus Cerebri
Crus Cerebri
Pons
Midbrain
21Haines Atlas (7th) 6-25
??
???
DC-ML
*
*
*
*
*
*
22Haines Atlas (7th) 6-25
ML
Rostral midbrain: III-n. nucleus, SC, R.N.
DC-ML
*
*
*
*
*
*
23
Haines Atlas (7th) 6-26
MLarm
leg
Midbrain/diencephalic junction: level of pretectal area/PC
DC-ML
* *PC
*
24
Haines Atlas (7th) 6-30 Thal
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??.
???.
???
?????
??????
???
???
???
DC-ML
??
25
Haines Atlas (7th) 6-30 Thal
III
Ant.
Post.
Pulvinar
CMVPL
VPMIntCap-post
Pineal
Forebrain (oblique axial): VP/ Pulvinar, CM, Pineal
SS Rad.
DC-ML
MD
26Haines Atlas (7th) 6-33
???
Oblique coronal
DC-ML
????
???
??
??? ???
?? ??
27Haines Atlas (7th) 6-33
Int. Caps.: posterior limb
Oblique coronal
DC-ML
Somatosensory radiations
Level of Ant Thalamic Nucleus & SubThalamus
SubThal
Subst Nigra
Subst Nigra
Ant Ant
28
Dorsal Column-Medial Lemniscal System
ArmLeg
Somatotopic representation in SI
•Leg - medial (ACA)
•Arm- lateral (MCA)
Haines Atlas (7th) 8-4
•Accurate stimulus localization possible if projs. mapped somatotopically (homunculus) in cerebral cortex
Int. Caps.
29
Anterolateral System
ALS
•Pain/Temperature
•Light (crude) touch
•ALS pathways: Spinothalamic, Spinoreticular, Spino-tectal (mesencephalic)
•At least 20 neurons
•Lower brainstem: ALS
•Upper midbrain: mainly Spinothalamic Tract (spinal lemniscus)
Haines Atlas (7th) 8-6
Spinal lemniscus
ALS
ALS
VPL
30
Large-dia. myelinated fibers: medial entry
Dorsolateral tract of
Lissauer
Haines Atlas (7th) 6-2
P/T fibers: lateral entry
Substantia galatinosa: lamina II
ALS: tract fibers- arise from superficial & deep DH layers
ALS: Spinothalamic, Spinoreticular, Spinotectal
ALS
AWC
Lumbosacral Enlargement (L4)
31Haines Atlas (7th) 6-4
arm
leg
C7: Cervical enlargement
ALS
ALSALS
32
Haines Atlas (7th) 6-9
Caudal/mid Medulla: DCN
G. N. & fasc.
C.N.
C.N.
Medial lemniscus
ALS
ALS
33
Haines Atlas (7th) 6-12
ALS
Rostral Medulla
Cochlear nucleus
ALS
*
34Haines Atlas (7th) 6-17
Lower pons: level of facial colliculus, VII n./nucleus
ML
ALS
VII (motor) nucleus
ALS
35
Haines Atlas (7th) 6-19
ML
ALS
Midpons: V nerve entry (chief sensory/motor V)
ALS
S M
V nerve
Base
Tegmentum
36
Haines Atlas (7th) 6-23
ML
ALS: spinal lemniscus
ALS
Lower midbrain: Trochlear (4th) nucleus/ x- SCP
4th 4th
x- SCPSubs. Nigra
37Haines Atlas (7th) 6-25
ML
Rostral midbrain: III-n. nucleus, SC, R.N.
spinal lemniscus
ALS
38
Haines Atlas (7th) 6-30
III
Ant.
Post.
pulvinar
CMVPL
VPMIntCap-post
Pineal
Forebrain (oblique axial): VP/ Pulvinar, CM, Pineal
& Subthalamus
ALS
39Haines Atlas (7th) 6-31
MDLat.
Int. Caps.: posterior limb
ALS
Somatosensory radiations
LD
Forebrain coronal thru LD/ Subthalamus
40
Anterolateral System
Somatotopic representation in SI
•Leg- medial
•Arm- lateral
Arm Leg
ALSHaines Atlas (7th) 8-6
41
VTTT
Trigeminal System
3 brainstem sensory nuclei:
•Chief sensory
•Spinal trigeminal nucleus
•Mesencephalic nucleus V
•Fine touch, vibration
•Pain/temp. (V, VII, IX, X)
•Proprioceptive
•VTTT: x trig. pathway•ALL P/T AND
•DTTT: un-x trig. Pathway •Fine touch only
DTTT
TrigHaines Atlas (7th) 8-9
•Midpons- V-nerve entry
•Midpons thru medulla
•MOST fine touch, vibration
VII
IX
X
V
•Starts above midpons
•Fully formed in midbrain
42
Haines Atlas (7th) 6-8
Spinal Trig. Nucleus/tract of V
Pyramidal decussation
Trig
Caudal Medulla: DCN/pyramidal decus.
DCN DCN
43
Haines Atlas (7th) 6-11
MLF
TST
ML
Rostral Medulla: XII n. nucleus/ Inf. Olive
XIIXII
Sp Trg Tr & Nu V
Sp Trg Nu & Tr V
VTTTVTTT is lateral to Medial Lemniscus in medulla (no DTTT)
44Haines Atlas (7th) 6-16
Lower pons: facial colliculus
Spinal Trig. Nucleus/tract of V-
lateral to VII n.
Trig
* *
45Haines Atlas (7th) 6-19
S M
Chief sensory V
Mesencephalic V
Trig
VTTT
VTTT dorsal to ML
No DTTT
ML
46
DTTT
VTTT
Haines Atlas (7th) 6-20
Rostral pons/Caudal midbrain: level of V n./ IV n. exits
V nerve
IV nerve
ML
Trig
ALS
47
Haines Atlas (7th) 6-22
Caudal midbrain: Level of Inf. Colliculus
Rostral pons
ML
X SCP
VTTT
DTTT
Spinothalamic Tract
Trig
48
Haines Atlas (7th) 6-26
MLSpinothalamic
tract
DTTT
VTTT
Trig
ML
Midbrain/diencephalic junction: level of pretectal area/PC/pineal
49
Haines Atlas (7th) 6-30
III
Ant.
Post.
pulvinar
CMVPL
VPMIntCap-post
Pineal
Forebrain (oblique axial): VP/ Pulvinar, CM, Pineal
Trig
50
Haines Atlas 5-32
Int. Caps.: posterior limb
Trig
Somatosensory radiations
Forebrain coronal thru Ant Thal Nu / MB
51
Trigeminal System
•Lateral: near Sylvian fissure
Haines Atlas (7th ) 8- 9 Trig
Representation of face in SI
•Post to Broca area (left)