The Human Brain During the Third Trimester

Moto r

nucleus

(VII)

Moto r

nucleus

(VII)

Moto r

nucleus

(VII)

Moto r

nucleus

(VII)

Ansiform

lobule

(Crus II HVIIA)

Ansiform

lobu le

(Crus II HVIIA)

Nerves VII and VIII?

Fourth

ventricle

Fourth

ventricle

Fourth

ventricle

Fourth

ventricle

CEREBELLAR

HEMISPHERE

CEREBELLAR

HEMISPHERE External germinal

layer

Germinal trigone (continuous with the

germinal source of the choroid plexus)

Raphe nuclear complexRaphe nuclear complex

Raphe nuclear complexRaphe nuclear complex

Reticula

r

formatio

n

Reticula

r

formatio

n

Paramedian

lobule?

(HVIIB)

Paramedian

lobu le?

(HVIIB)

Flocculus

(HX)

Flocculus

(HX)

Tr anspontine corticofugal

tract (thick longitudinal

bundles)

Pontocerebellar fiber s

(thin transve rse bundles)

Pontocerebellar fiber s

(decussation)

PONSPONS

MEDULLAMEDULLA

SPINAL CORD

Pontine

gray

Pontine

gray

Dorsal longitudinal

fasciculus

Dorsal longitudinal

fasciculus

Choroid

plexus

Choroid

plexus

Choroid

plexus

Choroid

plexus

Dorsal and ve ntral cochlear nuclei

Dorsal and ve ntral cochlear nuclei

Cun

eate

nu

cleu

s

Cun

eate

(^) nu
cleu
s
Cu
nea
nuc te
leu
s
Cu
nea
nuc te
leu
s
Spin
oce
rebe
llar
trac
ts
Spin
oce
rebe
llar
trac
ts
Lateral
corticospinal
tract
Lateral
corticospinal
tract
Ventral white commissure
Spinocephalic
(spinothalamic) tracts
Ventral corticospinal tract
Intraspinal tracts
(intermingled with the
medial longitudinal fas-
ciculus and tectospinal tract)
Central canal
Spinocerebellar tracts
Spin
al n
ucle
us
and
tra
ct (^) (V
)
Spin
al n
ucle
us
and
tra
ct (^) (V
)
Spinal nucleus
and tract (V
)
Spinal nucleus
and tract (V
)
S
up
er
io
r
ol
iv
e
co
m
pl
ex
S
up
er
io
r
ol
iv
e
co
m
pl
ex
uS
ep
ir
ro
(^) o
vil
e
oc
m
lp
xe
uS
ep
ir
ro
(^) o
vil
e
oc
m
lp
xe
Tr
ap
ez
oi
d
bo
d
y
an
d
m
ed
ia
l (^) l
em
n
is
cu
s
Tr
ap
ez
oi
d
bo
d
y
an
d
m
ed
ia
l (^) l
em
n
is
cu
s
Middle
cerebellar
peduncle
Middle
cerebellar
peduncle
Middle
cerebellar
peduncle
Middle
cerebellar
peduncle
Inferior
cerebellar
peduncle
Inferior
cerebellar
peduncle
Hypoglossal nucleus? (XII)Hypoglossal nucleus? (XII)
So
lita
ry
(^) nu
cle
us
(^) an
d (^) t
ra
ct
So
lita
ry
(^) nu
cle
us
(^) an
d (^) t
ra
ct

G

ra

c

il

e

fa

scic

ulus

G

ra

c

il

e

fa

scic

ulus

Gracile

nucleus?

Gracile

nucleus?

Medial

longitudinal

fasciculus?

Medial

longitudinal

fasciculus?

NeNerve VI?rve VI?

Dorsal motor nucleus? (XDorsal motor nucleus? (X))

Dorsal sensory nucleus? (XDorsal sensory nucleus? (X))

In

fe

ri

orc

ereb

ellar

peduncle

In

fe

ri

orc

ereb

ellar

peduncle

Spin

al^ n

ucleu

s^ (V

)

Spin

al^ n

ucleu

s^ (V

)

Spin

al^ nu

cleu

s^ (V

)

Spin

al^ nu

cleu

s^ (V

)

Lissauer's tract?

Myelination gliosis

(lateral funiculus)

Myelination gliosis

(ventral funiculus)

Myelination gliosis

(dorsal funiculus)

Medullary glio-

epithelium/ependyma

Medullary glio-

epithelium/ependyma

Germinal and transitional

structures in italics

Germinal and transitional

structures in italics

Glioepithelium

(middle cerebellar peduncle)

Fourth ve ntricle (lateral recess)

Cune

ate f

ascic

ulus

Cune

ate f

ascic

ulus

PLATE 242B