The Human Brain During the Third Trimester

External germinal layer

Germinal and transitional structures in italics

Principal sensory nucleus (V)

Superior cerSuperior cerebellar peduncleebellar peduncle

Superior^ c

erebellar^ p

eduncle

Superior^ c

erebellar^ p

eduncle

Middle cerMiddle cerebellar peduncleebellar peduncle

Middle and inferior

cerebellar peduncles

Middle and inferior

cerebellar peduncles

Choroid

plexus

Choroid

plexus

Mi

ddl

e (^) a
nd
(^) inf
eri
or
cer
ebe
lla
r (^) p
edu
ncl
es
Mi
ddl
e (^) a
nd
(^) inf
eri
or
cer
ebe
lla
r (^) p
edu
ncl
es
Interpositus
nucleus
Interpositus
nucleus
Dentate nucleuDentate nucleuss
Interpositus
nucleus
Interpositus
nucleus
Germinal
trigone
Germinal
trigone
Dentate nucleuDentate nucleuss
Medial longitudinal fasciculuMedial longitudinal fasciculuss
Spinotectal tractSpinotectal tract
Dorsal longitudinal fasciculuDorsal longitudinal fasciculuss
P O N SP O N S
T
ube
r
VIIb
T
ube
r
VIIb
F
oliu
m
VIIa
Fo
liu
m
VIIa
Pyramis
VIII
Pyramis
VIII
Nodulus
X
Nodulus
X
Uvul
a
IX
Uvul
a
IX
Anterior lobe
HI-HV
Anterior lobe
HI-HV
Simplex
lobule
HVI
Simplex
lobu le
HVI
Locus coeruleuLocus coeruleuss
Mesencephalic nuc. (VMesencephalic nuc. (V))
Reticular
formation
Reticular
formatio n
Primary fissu re
Primary fissure
Ve
stib
ula
r^
nu
cle
ar
co
m
ple
x
Ve
stib
ula
r^
nu
cle
ar
co
m
ple
x
Ve
stib
ula
r n
ucl
ear
com
ple
x
Ve
stib
ula
r n
ucl
ear
com
ple
x
Vestibular nuclear
complex
Vestibular nuclear
complex
Lateral vestibular
nucleus?
Lateral vestibular
nucleus?
Ve
ntr
al
teg
m
en
tal
nu
c.
Ve
ntr
al
teg
m
en
tal
nu
c.
M
ed
ia
ll
em
ni
sc
u
s
M
ed
ia
ll
em
ni
sc
u
s
Spinocephalic tractSpinocephalic tract
Ansiform lobule
(Crus I HVIIA)
Ansiform lobu le
(Crus I HVIIA)
An
sif
or
m
lo
bu
le
(C
ru
s (^) I
I (^) H
V
IIA
)
An
sif
or
m
lo
bu
le
(C
ru
s (^) I
I (^) H
V
IIA
)
PParabrachial nuc.arabrachial nuc.
Raphe
nuclear
complex
Raphe
nuclear
complex
Reticular tegmental
nucleus of pons
Reticular tegmental
nucleus of pons
Ve ntral nucleus of the lateral lemniscus?
Pontocerebellar fibers
Pontocerebellar fibers
(decussation)
Principal sensory nucleus (V)
Principal sen-
sory nuc. (V)
Principal sen-
sory nuc. (V)
Motor nucleus (VMotor nucleus (V))
Fibers of the trigeminal neFibers of the trigeminal nerve (Vrve (V))
Fourth
ventricle
Fourth
ventricle
(lateral recess)
Fourth
ventricl e
(lateral recess)
Lateral
lemniscus
Lateral
lemniscus
Ce rCere bellar deep nucleiebellar deep nuclei
VERMISVERMIS
HEMISPHEREHEMISPHERE
CEREBELLUM
PPontine grayontine gray
Transpontine
corticofugal tract
Pontine
glioepithelium/
ependyma
PLATE 91B