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I APPENDIX
f : N - i I, }4 T I A
I N T R O D U C TION
ANATOMYOF THE BRAIN
SURFACE
THE LATERALSURFACEOFTHE BRAIN
/o) CrossFeotures
(b) SelectedGyri,Sulci,ond Fissures
(c) CerebrolLobesond the Insulo
Areosof Cortex
(d) Mojor Sensory,Motor,ond Associotion
THE MEDIAL SURFACEOF THE BRAIN
(o) BroinStem Structures
An Illustrated
Guide to Human
Neuroematomy
FT
&
(b) ForebroinStructures
(c) Ventricles
THEVENTRALSURFACEOF THE BRAIN
THE DORSAL SURFACEOFTHE BRAIN
(o) Cerebrum
(b) CerebrumRernoved
(c) Cerebrumond CerebellumRemoved
ANATOMYOFTHE BRAIN
CROSS.SECTIONAL
AT THALAMUS-TELENCEPHALON
CROSS
SECTION| : FOREBRAIN
JUNCTION
(o) GrossFeotures
(b) Selected
Cellond FiberGroups
AT MID-THALAMUS
CROSS
SECTION2: FOREBRAIN
(o) GrossFeotures
(b) Selected
Cellond FiberGroups
ATTHALAMUS-MIDBRAIN
SECTION3: FOREBRAIN
CROSS
JUNCTION
(o) GrossFeotures
(b) Se/eaedCellond FiberGrouPs
MIDBRAIN
SECTION4: ROSTRAL
CROSS
CROSS
SECTION5: CAUDALMIDBRAIN
CROSS
SECTION6: PONSAND CEREBELLUM
MEDULLA
CROSS
SECTION7: ROSTRAL
SECTION8: MID-MEDULLA
CROSS
CORDJUNCTION
CROSS
SECTION9: MEDULLA-SPINAL
TH ES P I N A COR
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D
THE DORSALSURFACE
OFTHE SPINALCORDAND SPINALNERVES
SURFACE
THEVENTRAL-LATERAL
ANATOMY
CROSS-SECTIONAL
SYSTEM
THEAUTONOMICNERVOUS
THE CRANIALNERVES
THE BLOODSUPPLY
OF THE BRAIN
VENTRALVIEW
LATERALVIEW
(BRA|NSTEMREMOVED)
MEDTALVTEW
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206
C HAPTE R 7
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APPENDIX:AN
ILLUSTRATED
GUIDETOHUMANNEUROANATOMY
W IN TRODUCTION
As we will see in the remainder of the book, a fruitful way to explore the
nervous system is to divide it up into functional systems. Thus, the otfactlry systemconsistsof those parts of the brain that are devoted to the sense
of smell, the visual systemincludes those parts that are devoted to vision,
a n d s o o n . w h i l e t h i s f u n c t i o n a l a p p r o a c h t o i n v e s t i g a t i n gn e r v o u s s y s tem structure has many merits, it can make the "big picture,,-how all
these systemsfit rogether inside the box we call the brain-difficult ro see.
T h e g o a l o f t h i s I l l u s t r a t e d G u i d e i s t o h e l p y o u l e a r n , i n a d v a n c e ,a t r o u t
s o m e o f t h e a n a t o m y t h a t w i l l b e d i s c u s s e di n t h e s u b s e q u e n t c h a p t e r s .
H e r e w e c o n c e n t r a t eo n n a m i n g t h e s t r u c t u r e sa n d s e e i n g h o w t h e y a r e
r e l a t e d p h y s i c a l l y ; t h e i r f u n c t i o n a l s i g n i f i c a n c ei s d i s c u s s e di n t h e r e mainderof the book
The Guide is clrganizedinto six main parts. The first part covers the surface anatomy of the brain-the structures that can been seen by inspection
of the whole brain, as well as those parts that are visible when the two
c e r e b r a lh e m i s p h e r e sa r e s e p a r a t e db y a c u t i n t h e m i d s a g i t t a lp l a n e . N e x t ,
w e e x p l o r e t h e c r o s s - s e c t i o n aaln a t o m y o f t h e b r a i n , u s i n g a s e r i e so f s l a b s
t h a t c o n t a i n s t r u c t u r e so f i n t e r e s t .T h e b r i e f t h i r d a n d f o u r t h p a r t s c o v e r t h e
s p i n a l c o r d a n d t h e a u t o n o m i c n e r v o u s s y s t e m .T h e f i f t h p a r t o f t h e G u i d e
i l l u s t r a t e st h e c r a n i a l n e r v e s a n d s u m m a r i z e st h e i r d i v e r s e f u n c t i o n s . T h e
l a s t p a r t i l l u s t r a t e st h e b l o o d s u p p l y o f t h e b r a i n .
T h e n e r v o u s s y s t e mh a s a n a s t o n i s h i n gn u m b e r o f b i t s a n d p i e c e s .I n t h i s
G u i d e , w e f o c u s o n t h o s e s t r u c t u r e st h a t w i l l a p p e a rl a t e r i n t h e b o o k w h e n
we discussthe various functional systems.Nonetheless,even this abbreviated atlas of neuroanatomy yields a formidable list of new vocabulary.
Therefore, to help you learn the terminology, an extensive self-quiz review
is provided at the end, in the form of a perforated workbook with labeling
exercises.
'W
SURFACEANATOMY OF THE BRAIN
Imagine that you hold in your hands a human brain that has been diss e c t e df r o m t h e s k u l l . I t i s w e r a n d s p o n g y a n d w e i g h s a b o u t 1 . 4 k g
( 3 l b ) . L o o k i n g d o w n o n t h e b r a i n ' s d o r s a l s u r f a c er e v e a l st h e c o n v o l u t e d
surface of the cerebrum. Flipping the brain over shows the complex vent r a l s u r f a c et h a t n o r m a l l y r e s t so n t h e f l o o r o f t h e s k u l l . H o l d i n g t h e b r a i n
up and looking at its side-the lateral view-shows the ,,ram.shorn,, shape
of the cerebrum coming off the stalk of the brain stem. The brain stem is
shown more clearly if we slice the brain right down the middle and view
i t s m e d i a l s u r f a c e .I n t h e p a r t o f t h e G u i d e t h a t f o l l o w s , w e w i l l n a m e t h e
important structures that are revealed by such an inspection of the brain.
N o t i c e t h e m a g n i f i c a r i o no f t h e d r a w i n g s : l x i s l i f e - s i z e ,2 X i s t w i c e l i f e s i z e ,0 . 6 X i s 6 0 " / . o f l i f e - s i z e .a n d s o o n .
205
Lateral view
Medialview
208
c HApTER
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AppENDTX:AN
TLLUsTMTED
GUTDEToHUMANNEURoANAToMy
The Lateral Surface of the Brain
(a) Gross Features. This is a life-size drawing of the
brain. Gross inspection reveals the three major parts: the
large cerebrum, the brain stem that forms its stalk, and
the rippled cerebellum. The diminutive olfacrory bulb of
the cerebrum can also be seen in this lateral view.
Cerebrum
Olfactorybulb
Cerebellum
:
i,-
"
(b) Selected Gyri, Sulci, and Fissures. The cerebrum is
noteworthy for its convoluted surface. The bumps are
called gyri, and the grooves are called sulci or, if they are
especially deep, fissures. The precise pattern of gyri and
sulci can vary considerably from individual to individual,
but many features are common to all human brains. Some
of the important landmarks are labeled here. The post-
SURFACEANATOMY
OFTHEBRAIN
central gyrus lies immediately posterior to the cenlral sr.rlcus, and the precentral gyrus lies immediately anterior to
the central sulcus. The neurons of the postcentral gyrus
are involved in somatic sensation (touch; Chapter 12),
and those of the precentral gyrus control voluntary movement (Chapter l4). Neurons in the superior lemporal
gyrlrs are involved in audition (hearing; Chapter ll).
Centralsulcus
Lateral(Sylvian)
fissure
(c) Cerebral Lobes and the Insula. By convention,
the cerebrum is subdivided into lobes named after the
bones of the skull that lie over them. The central sulcus
d i v i d e st h e l r o n t a l l o b e f r o m t h e p a r i e t a l l o b e . T h e t e m pural lobc lies immediately ventral to the deep lateral
( S y l v i a n ) f i s s u r e .T h e o c c i p i t a ll o b e l i e s a t t h e v e r y b a c k
of the cerebrum, bordering both parietal and temporal
lobes. A buried piece of the cerebral cortex, called the
" i s l a n d " ) , i s r e v e a l e di f t h e m a r g i n s o f
insula (Latin for
the lateral fissure are gently pulled apart (inset). The
insula borders and separatesthe temporal and frontal
lobes.
Frontallobe
Occipitallobe
: .
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A p p E N D T X : ATNL L U S T R A T E D G U T D E T o H UNM
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(d) Major Sensory, Ivlotor, and Association Areas of
Cortex. The cerebral cortex is organized like a patchwork quilt. The various areas, first identified by Brodmann, differ from one another in terms of microscopic
structure and function. Visual areas L7, 18, and l9
(Chapter l0) are in the occipital lobe, somatic sensory
areas l, l, and 2 (Chapter 12) are in the parietal lobe,
and auditory areas4l and 42 (Chapter lI) are in the
temporal lobe. On the inferior surface of the parietal
lobe (the operculum) and buried in the insula is gustatory area 43, devoted to the sense of taste (Chapter 8).
In addition to the analysis of sensory information. the
cerebral cortex plays an important role in the control of
voluntary movement. The major motor control areasprimary motor cortex (area 4). the supplementary motor
area, and the premotor area-lie in the frontal lobe, anterior to the central sulcus (Chapter I4). In the human
brain, large expanses of cortex cannot be simply assigned
to sensory or motor functions. These constitute the association areas of cortex. Some of the more important
areasare the prefrontal cortex (Chapters 2l and 24), the
p o s t e r i o rp a r i e t a l c o r t e x ( C h a p t e r s1 2 , 2 1 , a n d 2 4 ) , a n d
t h e i n f e r o t e m p o r a lc o r t e x ( C h a p t e r 2 4 ) .
Brodmann's
mao
Primarymotorcortex
(area4)
Somatosensory
cortex
Supplementary
motorarea
(areas3, 1,2)
(area6)
Posteriorparietalcortex
(areas5, 7)
Premotor
area
(area6)
Visualcortex
( a r e a 1s 7 , 1 8 1, 9 )
Prefrontalcortex
Inferotemporal
cortex
(areas20,21,37)
I Motorareas
ffi Sensoryareas
areas
! Association
Auditory
cortex
(areas
41,42)
Gustatory
(area43)
:
r.l
ffil
ji
..:] SURFACEANATOMY
OFTHEBRAIN
The Medial Surface of the Brain
(a) Brain Stem Structures. Splitting the brain down
the middle exposesthe medial surface of the cerebrum,
shown in this life-size illustration. This view also shows
the midsagittal cut surface of the brain stem, consisting
o f t h e d i e n c e p h a l o n( t h a l a n r r r as n d h 1 ' l l o t l r a l a r r r r rtsh)e.
r t t i c l t r r a i r( t e c l r r r na n d l c g n r e n t r r r r r )t h
, e l l o r r s ,a n d t h e
n r c t l r r l l a .( S o m e a n a t c l m i s t sd e f i n e t h e b r a i n s t e m a s c o n s i s t i n go n l y o f t h e m i d b r a i n , p o n s , a n d m e d u l l a . )
Thalamus
Y (
Pinealbody
b*^
Hypothalamus
Cerebellum
212
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AppENDtX:ANILLUSTMTED
GUIDEToHUMANNEURoANAToMy
(b) Forebrain Structures. Shown here are the important forebrain structures that can be observed by
viewing the medial surface of the brain. Notice the
c u t s u r f a c eo f t h e c o r p u s c a l l o s u m , a h u g e b u n d l e o f
axons that connects the two sides of the cerebrum.
The unique contributions of the two cerebral hemis p h e r e st o h u m a n b r a i n f u n c t i o n c a n b e s t u d i e d i n
patients in which the callosum has been sectioned
(Chapter 20). The lornix is another prominent fiber
bundle that connects the hippocampus on each side
with the hypothalamus. (Fornix is Latin for "arch.")
Some of the axons in the fornix regulate memory
s t o r a g e( C h a p t e r 2 4 ) .
In the lower illustration, the brain has been tilted
s l i g h t l y t c l s h o w t h e p o s i t i o n so f t h e a n r l , g d a l aa n d h i p p o c a n r p u s .T h e s e a r e " p h a n t o m v i e w s " o f t h e s e s t r u c tures, becausethey cannot be observed directly frclm the
surface. Both lie deep to the overlyinll correx. We will
see them again in cross section later in the Guide. The
amygdala (Latin for "almond") is important for regulati n g e m o t i o n a l s t a t e s( C h a p t e r l 8 ) , a n d t h e h i p p o c a m p u s
is important for memory (Chapters 24 and 25\.
'(
Cingulategyrus
,,,ffi
f^*,
t*'\
Corpuscallosum
(cut edge)
/'rp-
'v
Olfactorybulb/
2*
Calcarinefissure
Opticchiasm
(0.7x)
; \ -
(0.7x)
Amygdala
(beneathoverlyingcortex)
Hippocampus
(beneathoverlyingcortex)
Brainstem and cerebellum
removedand brain
rotatedslightly
V SURFACEANATOMY
OFTHEBRAIN
(c) Ventricles. The lateral walls of the unpaired parts of
the ventricular system-the third ventricle, the cerebral
aqueduct, the fourth ventricle, and the spinal canalcan be observed in the medial view of the brain. These
are handy landmarks, because the thalamus and hypothalamus lie next to the third ventricle; the midbrain lies
next to the aqueduct; the pons, cerebellum, and medulla
lie next to the fourth ventricle; and the spinal cord forms
the walls of the spinal canal.
The lateral ventricles are paired structures that sprout
like antlers from the third ventricle. A phantom view
of the right lateral ventricle, which lies underneath the
overlying cortex, is shown in the lower illustration.
The two cerebral hemispheres surround the two lateral
ventricles. Notice how a coronal section of the brain at
the thalamus-midbrain junction will intersect the
"horns" of the lateral ventricle of each hemisphere
twice.
Third ventricle
Cerebralaoueduct
Fourthventricle
Spinalcanal
Lateral ventricle
(beneathoverlyingcortex)
2'3
(0.7x)
Brainstemandcerebellum
removedand brain
rotatedslightly
214
c H A pr E R 7
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AppENDtX:
AN TLLUSTRATED
GUIDEToHUMANNEURoANAToMv
The Ventral Surface of the Brain
The underside of the brain has a lot of distinct anatomical features.Notice the nerves emerging from the brain
stem; these are the cranial ucr\'('s,which are illustrated in
more detail later in the Guide. Also notice the X-shaped
oplic chiasnrjust anterior to the hypothalamus. The chiasm is the place where many axons from the eyes decussate (cross)from one side to another. The bundles of axons anterior to the chiasm, which emerge from the backs
of the eyes, are the oplic ncrvcs. The bundles lying pclsterior to the chiasm, that disappearinto the thalamus, are
c a l l e dt h e o p t i c t r a c l s( C h a p t e rl 0 ) . T h e p a i r e dr r r . r r r r r r r i l larl' boclies(Latin for "nipple") are a prominent feature of
the ventral surface of the brain. These nuclei of the hypothalamus are part of the circuitry that stores memory
(Chapter 241 and are a major target of the axons of the
f o r n i x ( s e e ni n t h e m e d i a l v i e w ) . N o t i c ea l s o t h e o l l r t t o r v
t r t r l b s( C h a p t e r8 ) a n d t h e r n i r l b r . t i nl,) ( ) n sa, n d r n t ' r l r r l l a .
Olfactorybulb
Opticchiasm
*!ffi.ar*\
-{
Optic tract
Optic nerve
Hypothalamus
Mammillary
body
Midbrain
Cranialnerves
SURFACE
ANATOMYOFTHEBRAIN
2t5
The Dorsal Surface of the Brain
(a) Cerebrurm. The dorsal vicw of the Llrainis don'rin a t e d b y t h e l a r g e c e r e b r u n r .N o t i c c t h e p a i r e c lc e r e b r a l
h e m i s p h e r e s .T h e s c a r e c o n n e c t e c lb y t h c a x o n s o f t h e
( ( ) r ' l ) L rl \. r l l o s u r l ( C h a p t e r2 0 ) , w h i c h c a n b c s c c n i f t h e
h e m i s p h e r e sa r t : r e t r a c t e c ls l i g h t l y . T h c r n c c l i a lv i e w o f
t h e b r a i n , i l l u s t r a t e dp r e v i o t r s l y ,s h o w c c lt l t e c a l k r s u r l i n
c r o s ss e c t i o l t .
Corpuscallosum
hemisphere
--t
Centralsulcus
Longitudinal
cerebral
fissure
R i g h th e m i s p h e r e
2,5
c H A pr E R 7
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AppENDtX:ANILLUSTRATED
GUIDEToHUMANNEURoANAToMy
(b) Cerebrum Removed. The cerebellum dominates
the dorsal view of the brain if the cerebrum is removed
and the brain is tilted slightly forward. The cerebellum,
an important motor control structure (Chapter I4), is divided into two hemispheres and a midline region called
the vermis (Latin for "worm").
Lefl cerebellar
hemisphere
Rightcerebellar
hemisphere
Spinalcord
(c) Cerebrum and Cerebellum Removed. The top surface of the brain stem is exposed when both the cerebrum
and the cerebellum are removed. The major divisions of
the brain stem are labeled on the left side, and some specific structures are labeled on the right side. The pineal
body, lying atop the thalamus, secretesmelatonin and is
involved in the regulation of sleep and sexual behavior
Thalamus
(Chaptersl7 and l9). The superior colliculusreceives
direct input from the eyes (Chapter l0) and is involved in
the control of eye movements (Chapter l4), while the irrferior colliculusis an important component of the auditory
system (Chapter Ill. (Colliculzsis Latin for "mound.") The
cerebellarpeduncles are the large bundles of axons that
connect the cerebellum and the brain stem (Chapter l4).
Pinealbody
Superiorcolliculus
Midbrain
Inferiorcolliculus
.t,
-'!
i{
Cerebellarpeduncle
(cut surface)
Fourthventricle(floor)
'rr.
\
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i,
v cRoss-sEcroNALANAToMy
oFTHEBRATN
V CROSS.SECTIONALANATOMY
O F T H E B R A IN
Understanding the brain requires that we peer inside it,
and this is accomplished by making cross sections. Cross
sections can be made physically with a knife or, in the
case of noninvasive imaging of the living brain, digitally
with an MRI or a CT scan. For learning the internal organization of the brain, the best approach is to make
cross sections that are perpendicular to the axis defined
by the embryonic neural tube, called the neuraxis. Tll'e
neuraxis bends as the human fetus grows, particularly at
the junction of the midbrain and thalamus. Consequently, the best plane of section depends on exactly
where along the neuraxis we are looking.
In this part of the Guide, we take a look at drawings
of a series of cross-sectional slabs of the brain, showing
the internal structure of the forebrain (cross sections
l-3), the midbrain (crosssections4 and 5), the pons and
cerebellum (crosssection 6), and the medulla (crosssections 7-9). The drawings are schematic. meaning that
structures within the slab are sometimes projected onto
the slab's visible surface.
ForebrainSections
@
247
(
BrainStem Sections
2t8
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APPENDIX:AN
ILLUSTRATED
GUIDETOHUMANNEUROANATOMY
Cross Section l: Forebrain at
Thalam us-Telen cephalon Junction
( a ) G r o s s F e a t u r e s . T h e t e l e n c e p h a l o ns u r r o u n d s t h e
l a t e r a l v e n t r i c l e s ,a n d t h e l l t a l a n r r r ss u r r o u n d s t h e t h i r d
ventricle. In this section,the latcral vcntriclt's can be
s e e n s p r o u t i n g f r o m t h e s l i t l i k e t l r i r d v c n t r i c l t ' .T h e l r 1 ' p o t h a l a r r r L r fso, r m i n g t h e f l o o r o f t h e t h i r d v e n t r i c l e ,i s a
vital control center for many basic bodily functions
( C h a p t e r s1 5 - 1 7 1 .T h e i n s r r l a( C h a p t e r8 ) l i e s a t t h e b a s e
o f t h e l a t c r a l1 S i ' l v i a nl)i s s t r r r h
' , e r e s e p a r a t i n tgh e l r o n l a l
I o b c f r o m t h e l e r r r p o r a ll o b e . T h e h e t e r o g e n e o u sr e g i o n
l y i n g d e e p w i t h i n t h e t e l e n c e p h a l o n ,m e d i a l t o t h e i n s u l a a n d l a t e r a l t o t h e t h a l a m u s .i s c a l l e d t h e b a s a lI o r r ' b r ai n .
Lateralventricle
Thalamus
lnsula
Lateral(Sylvian)
f issure
Thirdventricle
Temporallobe
Hypothalamus
" CROSS-SECTIONALANATOMY
OFTHEBRAIN
219
(b) Selected Cell and Fiber Groups. Here we take a
more detailed look at the structures of the forebrain. The
i n t c m a l c a p s t r l ei s t h e l a r g e c o l l e c t i o no f a x o n s c o n n e c t i n g t h e c o r t i c a lr v h i l e n r a n er w i t h t h e t h a l a m u s , a n d t h e
c o r l ) u s c a l l < l s r u ni s t h e e n o r m o u s s l i n g o f a x o n s c o n necting the cerebral cortex of the two hemispheres.The
l o r n i x , s h o w n e a r l i e ri n t h e m e d i a l v i e w o f t h e b r a i n , i s
shown here in cross section where it loclps around the
stalk of the lateral ventricle. The neurclns of the closely
a s s o c i a t e ds ep l . r l a r c a ( f r o m s a e p t u m ,L a l i n f c l r " p a r t i t i o n " ) c o n t r i b u t ea x o n s t o t h e f o r n i x a n d a r e i n v o l v e d i n
memory storage(Chapter 24). Three important collect i o n s o f n e u r o n s i n t h e b a s a l t e l e n c e p h a l o na r e a l s o
s h o w n : t h e c a r r r l . r t en i r c l t ' r r s ,t h e l ) u l . r l n c r r ,a n d t h e
g l o b r r sp . r l l i d t r s .C o l l e c t i v e l y ,t h e s e s t r u c t u r e sa r e c a l i e d
t h e b a s a lg a n g l i aa n d a r e a n i m p o r t a n t p a r t o f t h e b r a i n
s y s t e m st h a t c o n t r o l m o v e m e n t ( C h a p t e r l 4 ) .
Fiber groups:
Putamen
Globuspallidus
C HAPTE R 7
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APPENDIX:
AN ILLUSTRATED
GUIDETOHUMANNEUROANATOMY
Cross Section 2: Forebrain at Mid-Thalamus
(a) Gross Features. As we move slightly caudal in the
n e u r a x i s , w e s e e t h e h e a r t - s h a p e dt h a l a r r r t r s( G r e e k f o r
"inner chamber") surrounding
the small llrird vcntricle
at the brain'score.Just ventral to the thalamus lies the
h 1 ' p o t h a l a r r r u sT.h e t e l e n c e p h a l o ni s o r g a n i z e d m u c h
Iike what we saw in cross section l. Becausewe are
slightly posterior, the lateral fissure here separatesthe
p a r i c t a ll o b c f r o m t h e t e n r p o r a lk l b c .
s
S
fr*F
,
/,
ldv
.\Cb
l
J
.
)
'
s
I
,f,-.
Lateralventricle
t
Thalamus
Lateral(Sylvian)
fissure
Thirdventricle
Temporallobe
Basalforebrain
Hypothalamus
(1x)
g CROSS.SECTIONALANATOMY
OFTHEBRAIN
(b) Selected Cell and Fiber Groups. Many important
cell and fiber groups appear at this level of the neuraxis.
One new structure apparent in the telencephalon is
t h e a r n y g c l a l a ,i n v o l v e d i n t h e r e g u l a t i o n o f e m o t i o n
(Chapter l8) and memory (Chapter 24). The thalamus
is divided into separatenuclei, two of which-the ventral posterior nucleus and the ventral lateral nucleus-
221
are labeled. The thalamus provides much of the input to
t h e c c r e b r a lc o r t c x , w i t h d i f f e r e n t t h a l a m i c n u c l e i p r o jecting axons to different areas of cortex. The ventral
p < l s t c r i o rn t r c l c u s ,a p a r t o f t h e s o m a t i c s e n s o r y s y s t e m
(Chapter l2), projectsto the cortex of the postcentral
g y r u s . T h e v c r r t r a l l a t c r a l n u c l c r r sa n d c l o s e l y r e l a t e d
ventral anterior nucleus (not shown) are parts of the
motor system (Chapter l4); they project to the motor
cortex of the precentral gyrus. Visible below the thalam u s a r e t h e s u l r t h a l a n r r rasn d t h e n t a n t n r i l l a r yl l o d i c so f
t h e h y p o t h a l a m u s . T h e s u b t h a l a m u si s a p a r t o f t h e
motor system (Chapter l4), while the mammillary bodies
receive information from the lornix and contribute to
t h e r e g u l a t i o n o f m e m o r y ( C h a p t e r 2 4 ) . B e c a u s et h i s
section also encroaches on the midbrain, a little of the
s t r l r s t a n l i .n. ri g r a ( " b l a c k s u b s t a n c e " )c a n b e s e e n n e a r t h e
b a s eo f t h e b r a i n s t e m . T h e s u b s t a n t i an i g r a i s a l s o a p a r t
o f t h e m o t o r s y s t e m ( C h a p t e r l 4 ) . P a r k i n s o n ' sd i s e a s e
r e s u l t sf r o m t h e d e g e n e r a t i o no f t h i s s t r u c t u r e .
Fornix
Corpuscallosum
Caudatenucleus
Putamen
Internalcapsule
Globuspallidus
Corticalwhite
matter
Amygdala
(1x)
Substantianigra
Subthalamus
Mammillary
body
C H A P T E R7
APPENDIX:
AN ILLUSTRATED
GUIDETOHUMANNEUROANATOMY
Cross Section 3: Forebrain at ThalamusMidbrain Junction
(a) Gross Features. The neuraxis bends sharply at the
junction of the thalamus and the midbrain. This cross
section is taken at a level where the teardrop-shaped
t l . r i r c lv e n t r i c l c c o m m u n i c a t e s w i t h t h e c t ' r r ' [ r r a la q r r r ' d t r c t .T h e b r a i n s u r r o u n d i n g t h e t h i r d v e n t r i c l e i s t l r a l a I t t u s ,a n d t h e b r a i n a r o u n d t h e c e r e b r a la q u e d u c ti s r r r i t l b r a i n . T h e l a t c r a lv e r r t r i c l c so f e a c h h e m i s p h e r ea p p e a r
t w i c e i n t h i s s e c t i o n .Y o u c a n s e e w h y b y r e v i e w i n g t h e
p h a n t o m v i e w o f t h e v e n t r i c l e ,s h o w n e a r l i e r .
?r,
Thirdventricle
Lateralventricle
W
Thalamus
\
Temporal
,"r"A
Midbrain
(1x)
Cerebralaqueduct
V CROSS.SECTIONALANATOMY
OFTHEBRAIN
223
(b) Selected Cell and Fiber Groups. Notice that this
sectioncontainstwo more important nuclei of the thalamus: the medial and lateral geniculatenuclei. (Geniculate is Latin for "knee.") The lateral geniculatenucleus
relaysinformation to the visual cortex (ChapterI0), and
the medial geniculatenucleus relays information to the
auditory cortex (Chapter lt). Also notice the location of
the hippocampus, a relatively simple form of cerebral
cortex bordering the lateral ventricle of the temporal
lobe. The hippocampus(Greek for "seahorse")plays an
important role in learning and memory (Chapters 24
and25).
Corpuscallosum
Cerebral
cortex
Lateralgeniculate
nucleus
W
Hippocampus
Medialgeniculate
nucleus
i
iiii
CHAPTER
7
.
APPENDIX:AN
ILLUSTMTED
GUIDETOHUMANNEUROANATOMY
Cross Section 4: Rostral Midbrain
We are now at the midbrain. The plane of section has
been angled relative to the forebrain sections, so that it
remains perpendicular to the neuraxis. The core of the
midbrain is the small cerebral aqueduct. Here, the roof
of the midbrain, also called the tectum (Latin for "roof"),
consists of the paired superior colliculi. As discussed
earlier, the superior colliculus is a part of the visual
system (Chapter i0) and the substantianigra is a part of
the motor system (Chapter t4). The red nucleus is also
a motor control structure (Chapter l4), while the periaqueductal gray is important in the control of somatic
pain sensations(Chapter l2).
Superiorcolliculus
Cerebralaqueduct
gray
Periaqueductal
Substantianigra
Rednucleus
Cross Section 5: Caudal Midbrain
The caudal midbrain appearsvery similar to the rostral
midbrain. At this level, however, the roof is formed by
the inferior colliculi(part of the auditory system;Chapter I I ) instead of by the superior colliculi. Review the
dorsal view of the brain stem to see how the superior
and inferior colliculi are situatedrelative to each other.
Inferiorcolliculus
Cerebralaoueduct
gray
Periaqueductal
;]\.
Substantia
nigra
(2x)
ti
v cRoss-sEcloNALANAToMy
oFTHEBn,lIN
225
Cross Section 6: Ponsand Cerebellum
This section shows the pons and cerebellum, parts of the
rostral hindbrain that border the fourth ventricle. As
mentioned earlier, the cerebellum is important in the
control of movement. Much of the input to the cerebellar cortex derives from the pontine nuclei, while the
output of the cerebellum is from neurons of the deep
cerebellar nuclei (Chapter 14). The reticular formation
(reticulumis Latin for "net") runs from the midbrain to
the medulla at the core of the brain stem,just under the
cerebralaqueduct and fourth ventricle. One function of
the reticular formation is to regulate sleep and wakefulness(Chapterl9). In addition,a function of the pontine reticular formation is to control body posture
(Chapterl4).
Fourthventricle
Cerebellar
cortex
Deepcerebellar
nuclei
Pontinenuclei
Cross Section 7: Rostral Medulla
As we move farther caudally along the neuraxis,the
brain surrounding the fourth ventricle becomesthe
medulla. The medulla is a complex region of the brain.
Here we focus only on those structureswhose functions
are discussedlater in the book. At the very floor of the
medulla lie the medullary pyramids,huge bundlesof axons descendingfrom the forebrain toward the spinal
cord. The pyramids contain the corticospinaltracts,
which are involved in the control of voluntary movement (Chapter14). Severalnuclei that are important for
hearing are also found in the rostral medulla: the dorsal
and ventralcochlearnucleiand the superiorolive (Chapter ll). Also shown are the inferior olive, important for
motor control (Chaptert4), and the raphe nucleus,important for the modulation of pain, mood, and wakefulness (Chapters12, 19, and 22\.
Dorsalcochlearnucleus
Ventralcochlear
nucleus
Raphenucleus
Superior
olive
Inferiorolive
Medullarypyramid
Fourthventricle
CHAPTER
7
.
A P P E N D I X : AIN
L L U S T M T EGDU I D E T OH U M A NN E U R O A N A T O M Y
CrossSection 8: Mid-Medulla
The mid-medulla contains some of the same structures
labeled in cross section 7. Notice also the medial lemniscus (Latin for "ribbon"). The medial lemniscus contains
axons bringing information about somatic sensation to
the thalamus (Chapter 12). The gustatory nucleus,
serving the sense of taste (Chapter 8), is part of a larger
nucleus of the solitary tract, which regulates aspectsof
v i s c e r a lf u n c t i o n ( C h a p t e r s l 5 a n d l 6 ) . T h e v e s l i b u l a r
nuclei serve the sense of balance (Chapter it).
Fourlhventricle
Vestibular
nucleus
Nucleusof the
solitarytract
(gustatory
nucleus)
Medullaryreticular------tl-"il
formation
Inferiorolive
Mediallemniscus
Cross Section 9: Medulla-SpinalCord
Junction
As the medulla disappears,so does the fourth ventricle,
now replacedby the beginning of the spinal canal. Notice
the dorsal column nuclei, which receive somatic sensory
information from the spinal cord (Chapter l2). Axons
arising from the neurons in each dorsal column nucleus
crossto the other side of the brain (decussate)and ascend
to the thalamus via the medial lemnisctrs.
Dorsalcolumnnuclei
Spinalcanal
Mediallemniscus
Medullarypyramid,/
V THE SPINAL CORD
The Dorsal Surface of the Spinal Cord
and Spinal Nerves
The spinal cord lies within the vertebral column. The
spinal nerves, a part of the somatic PNS, communicate
with the cord via notches between the vertebrae. The
vertebrae are described according to their location. In
the neck, they are called cervical vertebrae and are
numbered from Cl to C7. The vertebrae attached to ribs
are called thoracic vertebrae and are numbered from Tl
to T12. The five vertebrae of the lower back are called
**,:+;ir.rfiiiili_i**r
(2.5X)
lumbar, and those within the pelvic area are called
s a c r al .
The spinal nerves and the associatedsegments of the
spinal cord adopt the names of the vertebrae; eight cervical nerves are associatedwith seven cervical vertebrae.
Also. the spinal cord in the adult human ends at about
the level of the third lumbar vertebra. This disparity
arisesbecausethe spinal cord does not grow after birth,
whereas the spinal column does. The bundles of spinal
nerves streaming down within the lumbar and sacral
vertebral column are called the cauda equina (Latin for
"horse's
tail").
"
THESPINAL
CORD
lst cervicalnerve
1stcervicalvertebra(C1)
7th cervicalvertebra(C7)
8th cervicalnerve
1st thoracicvertebra(T1)
1st thoracicnerve
12ththoracicvertebra(Tl 2)
12ththoracicnerve
1st lumbarvertebra(L1)
1st lumbarnerve
Caudaequina
5thlumbarvertebra(L5)
sth lumbarnerve
(S1)
1stsacralvertebra
1stsacralnerve
227
228
c HApTER
7
.
AppENDtX:ANILLUsTMTED
GUIDEToHUMANNEURoANAToMy
The Ventral-Lateral Surface
of neuronal cell bodies. The gray matter is divided into
the dorsal, lateral, and ventral horns. Notice how the
organization of gray and white matter in the spinal cord
differs from that in the forebrain. In the forebrain, the
gray matter surrounds the white matter; in the spinal
cord, it is the other way around. The thick shell of white
matter, containing the long axons that run up and down
the cord, is divided into three columns: the dorsal
columns, the lateral columns, and the ventral columns.
This view shows how the spinal nerves attach to the
spinal cord and how the spinal meninges are organized.
As the nerve passesinto the vertebral notch (not shown),
it splits into two roots. The dorsal root carries sensory
axons whose cell bodies lie in the dorsal root ganglia.
The ventral root carries motor axons arising from the
gray matter of the ventral spinal cord. The butterflyshaped core of the spinal cord is gray matter consisting
Dorsalhorn
Dorsalcotumns
/
Lateralcolumn
/
Al
l
/ , / ll
Spinalcanal
DORSAL
I
)-=Ventralhorn
Lateralhorn
Ventral
column
Dorsalroot filaments
Dorsalroot
Dorsalrootganglion
Spinalpia mater
Spinalnerve
Subarachnoid
space
Soinalarachnoid
Ventralroot
Soinaldura mater
Ventralroot
filaments
(6x)
VENTRAL
V THESPINAL
CORD
C ross-Sectional Anatomy
Illustrated in this view are some of the important tracts
of axons running up and down the spinal cord. On the
left side, the major ascending sensory pathways are indicated. The entire dorsal column consistsof sensory axons ascending to the brain. This pathway is important
for the conscious appreciation of touch. The spinothalamic tract carries information about painful stimuli and
temperature. The somatic sensory system is the topic of
Chapter 12.
On the right side are some of the descending tracts im-
Ascending
SensoryPathways
portant for the control of movement (Chapter I4). The
names of the tracts accurately describe their origins and
terminations (e.9., the vestibulospinal tract originates in
the vestibular nuclei of the medulla and terminates in
the spinal cord). The descending tracts contribute to two
pathways: the lateral and ventromedial pathways. The
lateral pathway carries the commands for voluntary
movements, especially of the extremities. The ventromedial pathway participates primarily in the maintenance of posture and certain reflex movements.
Descending
MotorPathways
Dorsalcolumn
\
tract \
Corticosoinal
'
v Laleral
\ pathway
Rubrospinaltract
\
Soinothalamictract
Medullary
reticulospinal
tract
Tectospinal
tract
Pontine
reticulosoinal
tract
Ventromedial
pathway
Vestibulosoinal
tract
230
c HApTER
7
.
A p p E N D t X : A INL L U s T M T EG
D U I D E T oH U M A NN E U R o A N A T o M y
V THE AUTONOMIC NERVOUSSYSTEM
In addition to the somatic PNS, which is devoted largely
to the voluntary control of movement and conscious
skin sensations,there is the visceral PNS, devoted to the
regulation of the internal organs, glands, and vasculature. Because this regulation occurs automatically and is
not under direct conscious control, this system is called
the autonomic nervous system, or ANS. The two most
important divisions of the ANS are the sympathetic and
p ar a s y m p a t h e t i cd i v i s i o n s .
The illustration on the facing page shows the cavity of
the body as it appearswhen it has been sectioned sagittally at the level of the eye. Notice the verrebral column,
which is encasedin a thick wall of connective tissue.The
spinal nerves can be seen emerging from the column.
Notice that the sympathetic division of the ANS consists
of a chain of ganglia that runs along the side of the vertebral column. These syrnpathetic ganglia communicate
with the spinal nerves, with one another, and with a
large number of internal organs.
The parasympathetic division of the ANS is organized
quite differently. Much of the parasympathericinnervation of the viscera arises from the vagus nerve, one of
the cranial nerves emerging from the medulla. The other
m a j o r s o u r c eo f p a r a s y r n l ) a t h e t ifci b c r si s t h e s a c r a ls p i n a l
nerves.
The two divisions of the ANS exert opposite effects
on body physiology. For example, the sympathetic nervous system speedsheart rate, while the parasympathetic nervous system slows it down. In general, the
sympathetic division is activated to prepare the body
for stressful conditions, such as escaping danger,
whereas the parasympathetic division is most active
under vegetative conditions, such as digesting a large
meal. (The functional organization of the ANS is disc u s s e di n C h a n t e r 1 5 . )
;'i;11:Il 1'-111;'1
ir
'
- .';"
t, il
11.",,:lr.
:al :i.,.:r'tr' triii:;
;iiii'l rr'.r'-r
V THEAUTONOMICNERVOUS
SYSTEM
Vagusnerve
Spinalnerves
Vertebral
column
Ribs of the
rightside (cut)
Kidney
Small intestine
Sympatheticganglia
Urinarybladder
Prostategland
Sympatheticfibers
Parasympathetic
fibers
231
232
c HAprE R 7
.
AppENDtX:ANILLUsTRATED
GUIDEToHUMANNEURoANAToMv
g THE CRANIAL NERVES
T W e l v ep a i r s o f c r . t r r i a ln ( ' r v e se m e r g e f r o m t h e b a s e o f
the brain. The first two "nerves" are actually parts of the
CNS, serving olfaction and vision. The rest are like the
s p i n a l n e r v e s ,i n t h a t t h e y c o n t a i n a x o n s o f t h e p N S . A s
the illustration shows, however, a single nerve clften has
fibers performing many different functions. I(nowledge
o f t h e n e r v e sa n d t h e i r d i v e r s ef u n c t i o n s i s a v a l u a b l ea i d
i n t h e d i a g n o s i so f a n u m b e r c l f n e u r o l o g i c a ld i s o r d e r s I. t
i s i m p o r t a n t t o r e c o g n i z et h a t t h e c r a n i a l n e r v e s h a v e
a s s o c i a t e dc r a n i a l n e r v e n u c l e i i n t l - r em i d b r a i n , p o n s ,
a n d m e d u l l a . E x a m p l e sa r e t h e c o c h l e a r a n d v e s t i b u l a r
nuclei, which receive information from cranial nerve
VIII. Most of cranial nerve nuclei were not illllstrated
o r l a b e l e d i n t h e b r a i n s t e m c r o s s s e c t i o n s .h o w e v e r .
b e c a u s e t h e i r f u n c t i o n s a r e n o t d i s c u s s e de x n l i c i t l v i n
this book.
--{
l. Olfactory
I
lV Trochlear
V.Trigeminal
Vl. Abducens
Vll. Facial
VlIl. Auditory-vestibular
lX. Glossopharyngeal
X. Vagus
Xl. Spinalaccessory
Xll. Hypoglossal
w' THEcRANTALNERVES
233
N E R V EN U M B E RA N D N A M E
TYPESOF AXONS
IMPORTANTFUNCTIONS
L Olfactory
Specialsensory
Sensation
of smell
ll. Optic
Specialsensory
Sensation
of vision
lll. Oculomotor
Somaticmotor
Visceralmotor
Movementsof the eye and eyelid
control of pupil size
Parasympathetic
lV.Trochlear
Somaticmotor
Movementsof the eye
V.Trigeminal
Somaticsensory
Somaticmotor
Sensationof touch to the face
Movementof musclesof mastication(chewing)
Vl.Abducens
Somaticmotor
Movementsof the eye
Vll. Facial
Somaticsensory
Specialsensory
Movementof musclesof facialexpression
Sensationof taste in anterior two-thirds of
the tongue
Vl IL Auditory-vestibular
Specialsensory
Sensationof hearingand balance
lX. Glossopharyngeal
Somaticmotor
Movementof musclesin the throat
(oropharynx)
control of the salivaryglands
Parasympathetic
Sensationof taste in posterior one-third of
the tongue
Detection of blood pressurechangesin the
aorta
Visceralmotor
Specialsensory
Visceralsensory
X.Vagus
Visceralmotor
Visceralsensory
Somaticmotor
control of the heart,lungs,
Parasympathetic
and abdominalorgans
Sensationof pain associatedwith viscera
Movementof musclesin the throat
(oropharynx)
Xl. Spinalaccessory
Somaticmotor
Movementof musclesin the throat and neck
Xll. Hypoglossal
Somaticmotor
Movementof the tongue
234
c HApr E R 7
.
AppENDTX:AN
TLLUSTRATED
GUTDEToHUMANNEURoANAToMy
g THE BLOOD SUPPLY
OF THE BRAIN
VentralView
Two pairs of arteries supply blood to the brain: the vcrt c b r a l a r t c r i c sa n d t h e i n l c r r r a lc a r o t i t la r t c r i c s T
. he vertebral arteries converge near the base of the pons to
f o r m t h e u n p a i r e d l r a s i l a ri ] 1 1 c r ] 'A. t t h e l e v e l o f t h e
midbrain, the basilar artery splits into the right and left
s r r p t ' r ' i o rc ' c r r ' [ r e l l aar r l t ' r i c s a n d t h e p o s t e r i o r c e r e b r a l
a r t e r i e s .T h e p o s t t ' r i r l r c c r c [ r r a l a r t er i c s s e n d b r a n c h e s ,
c a l l e d l l o s t c r i o r r ' o r n n t r r n i c a t i n aq r l c r i c s , t h a t c o n n e c t
them to the internal carotids. The internal carotids
b r a n c h t o f o r m t h e r t r i d d l e r ' r ' r r ' [ r r a.lr r . l c r i c sa n d t h e
a n t er i o r c c r c [ r r a la r t c r i c ' s T
. h e a n t e r i o r c e r e b r a la r t e r i e s
o f e a c h s i d e a r e c o n n e c t e db y t h e a n t c r i o r ( o n l n t r i n l ( . . 1 ing arlc'r1'.Thus, there is a ring of connected arteries at
the base of the brain, formed by the posterior cerebral
and communicating arteries, the internal carotids, and
the anterior cerebral and communicating arteries. This
ring is called the circleof Willis.
Anteriorcerebralartery
/\
Posteriorcerebral
artery
Superiorcerebellar
arrery
Basilarartery
(1x)
Vertebralarteries
V THEBLOODSUPPLY
OFTHEBRAIN
235
LateralView
Terminalcortical
branchesof anterior
Most of the lateral surfaceof the cerebrum is supplied
by the middle cerebralartery. This artery also feedsthe
deen structuresof the basalforebrain.
artery
cerebral
cortical
Terminal
of oosterior
branches
artery
cerebral
Middlecerebral
artery
MedialView (Brain Stem Removed)
Most of the medial wall of the cerebralhemisphere is
suppliedby the anterior cerebralartery. The posterior
cerebralartery feedsthe medial wall of the occipitalIobe
and the inferior part of the temporal lobe.
Anterior
cerebral
Posteriol
236
CHAPTER
7
.
APPENDIX:AN
ILLUSTMTED
GUIDETOHUMANNEUROANATOMY
v S E LF- QU|Z
This review workbook is designed to help you learn the neuroanatomy that
has been presented. Here we have reproduced the images from the Guide;
instead of labels, however, numbered leader lines (arranged clockwise)
point to the structures of interest. Test your knowledge by filling in the appropriate names in the spacesprovided. To review what you have learned,
quiz yourself by putting your hand over the names. This technique greatly
facilitates the learning and retention of anatomical terms. Mastery of the
vocabulary of neuroanatomy will serve you well as you learn about the
functional organization of the brain in the remainder of the book.
THE LATERAL SURFACEOFTHE BRAIN
(a) GrossFeatures
'i,
2.
F
I
5
t
tf
q.
1
4.
P,l
t'
i
*l
l.
I
'{: .
T
il
ii
ii,'
(b) SelectedGyri, Sulci,and Fissures
s._
/'
,
[.,,
[r
Jl.l
6 _
7_
8.. _
8
{
S',
ri
lt;
[i
tF
[:1
gj
,f,"
$'r
t,
{.r
i.r
ti
til
|il
ffi.
f t
f,:,
i"
V SELF.QUIZ
237
THE LATERAL SURFACEOFTHE BRAIN
(c) CerebralLobesandthe Insula
t.
7.
3.
4.
5.
(d) Major Sensory,Motor, and AssociationAreas of Cortex
6 .
7.
8.
9.
t0.
ll.
t2.
t3.
t4.
15.
i.
238
c H Apr E R 7
.
AppENDTX:AN
TLLUsTMTED
GUTDEToHUMANNEURoANAToMy
T H E M E D I A L S U R F A C EO F T H E B R A I N
(a) BrainStemStructures
t.
2.
3.
4.
5.
6.
7.
8.
9.
(b) Forebrain
Srructures
t0.
il.
12.
t3.
t4.
t5.
16.
t7.
V SELF.QUIZ
THE MEDIAL SURFACEOFTHE BRAIN
(c)Ventricles
t.
2.
3.
4.
5.
6.
THEVENTRAL SURFACEOFTHE BRAIN
(a) GrossFeatures
7.
8.
9.
11
12
r 0.
lt.
13
14
15
t2.
r3.
t4.
t5.
CHAPTER
7
.
APPENDIX:AN
ILLUSTMTED
GUIDETOHUMANNEUROANATOMY
THE DORSAL SURFACEOFTHE BRAIN
(a) Cerebrum
t.
2.
3.
4.
).
(b) Cerebrum Removed
7.
8.
9.
t0.
il.
(c) Cerebrum and Cerebellum Removed
t2.
13
14
15
t3.
t4.
16
t5.
17
t6.
i: :i
t7.
' i
:,
!
{. j
.;I
i l
:-: I
,:i
FOREBRAINAT THALAMUS-TELENCEPHALONJUNCTION
(a) GrossFeatures
t,^
c-----------l-\--
,'
r /'"-+
*'
- --t
L
/
|
{
\ - \
^r"
J
!
\
(b) SelectedCell and Fiber Groups
t0.
il.
tc
t2.
16
t3.
17
t4.
t5.
t5.
t7.
t8.
SELF-QUIZ
241
242
c H A pr E R 7
.
AppENDTX:
AN TLLUSTRATED
GUTDEToHUMANNEURoANAToMy
FOREBRAINAT MID.THALAMUS
(a) GrossFeatures
,>.
/'
9
+l "\ +t
l
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6.
8.
9.
t0.
il.
(b) SelectedCell and Fiber Groups
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t4.
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t7.
t8.
t9
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a l
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23
t., il::;;-rrl;,:;'a
r:;i|\,'::i!
ij,i
V SELF.QUIZ
FOREBRATN
AT THALAMUS-MtDBRA|N TUNCT|ON
(a) GrossFeatures
l.
2.
3.
4.
5.
6.
7.
(b) Selected
Cell and FiberGroups
8.
9.
t0.
il.
t2.
t3.
C H A PT E R 7
.
APPENDIX:
AN ILLUSTMTEDGUIDETOHUMAN NEUROANATOMY
ROSTRAL MIDBRAIN
t.
2.
3.
4.
5.
CAUDAL MIDBRAIN
6.
7.
8.
9.
PONS AND CEREBELLUM
t0.
il.
t2.
r3.
t4.
V SELF-QUIZ
ROSTRAL MEDULLA
t.
2.
3.
4.
5.
6.
7.
MID.MEDULLA
8.
9.
12
t0.
11
il.
10
t2.
t3.
14.
MEDULLA-SPTNALCORD TUNCTTON
t5.
t6.
17.
,u /' "
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C H A PT E R 7
.
APPENDIX:
AN ILLUSTMTEDGUIDETOHUMAN NEUROANATOMY
SPINAL CORD,VENTRAL.LATERAL SURFACE
t.
2.
3.
6
4.
5.
12
13
14
6.
7.
8.
9.
10.
il.
12.
t3.
I
VENTRAL
t4.
t5.
t6.
17.
t8.
t9.
20.
21.
22.
23.
24.
25.
26.
27.
28.
29.
v
THE CRANIAL NERVES
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3.
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4.
3
5.
4
6.
5
7.
o
7
8
o
8.
9.
10
11
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12
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SELF-QU|Z
CHAPTER
7
.
APPENDIX:AN
ILLUSTRATED
GUIDETOHUMANNEUROANATOMY
THE BLOOD SUPPLY OFTHE
BRAIN
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3.
4.
5.
6.
7.
8.
9.
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t2.
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