The Human Brain During the Third Trimester

Ventral

medial

nucleus

Ve ntral

medial

nucleus

A

n

te

r

io

r

l

o

b

e

(H

I

• H

V

)

A

n

te

r

io

r

l

o

b

e

(H

I

• H

V

)

Simplex

lobule

(HVI)

Simplex

lobu le

(HVI)

Primary fissure

Ansiform lobule

crus II

(HVIIA)

Ansiform lobu le

crus II

(HVIIA)

Ansiform lobule

crus I

(HVIIA)

Ansiform lobu le

crus I

Olfactory (HVIIA)

tubercle

Olfactory

tubercle

Orbital gyrusOrbital gyrus

Lateral

ventricle

Lateral

ventricle

Choroid

plexus

Choroid

plexus

Corpus

callosum

(splenium)

Corpus

callosum

(splenium)

BASAL

GANGLIA

BA SAL

GANGLIA

VENTRAL

HIPPOCAMPUS

VENTRAL

HIPPOCAMPUS

PulvinarPulvinar

P

O

S

T

E

R

IO

R

C

O

M

P

L

E

X

P

O

S

T

E

R

IO

R

C

O

M

P

L

E

X

Optic

tract

Optic

tract

Nucleus

accumbens

Nucleus

accumbens SubiculuSubiculumm

SubiculuSubiculumm

Anterior

commissure

Anterior

commissure

ChorChoroid plexusoid plexus

DORSAL

HIPPOCAMPUS

DORSAL

HIPPOCAMPUS

Cingulate gyrus

(r

et

r

osplenial ar

ea)

Cingulate gyrus

(r

et

rosplenial ar

ea)

Corpus callosu

m

Corpus callosu

m

CEREBELLUM

(HEMISPHERE)

CEREBELLUM

(HEMISPHERE)

M

id

dl

e

ce

re

be

lla

r^

pe

du

nc

le

M

id

dl

e

ce

re

be

lla

r^

pe

du

nc

le

Ventral

postero-

lateral

nucleus

Ve ntral

postero-

lateral

nucleus

Ventral

postero-

medial

nucleus

Ve ntral

postero-

medial

nucleus

Ventral

lateral

nucleus

Ve ntral

lateral

nucleus

Ventral

Anterior

nucleus

Ve ntral

Anterior

nucleus

THALAMUSTHALAMUS

Dentate nucleuDentate nucleuss

Para-

flocculus

(HIX)

Para-

flocculus

(HIX)

Biventral

lobule

(HVIII)

Biventra l

lobu le

(HVIII)

Paramedian

lobule

(HVIIB)

Paramedian

lobu le

(HVIIB)

Medial

geniculate

body

Medial

geniculate

body

In

te

rn

a

l

ca

p

su

le

(a

n

te

ri

o

r

li

m

b)

In

te

rn

a

l

ca

p

su

le

(a

n

te

ri

o

r

li

m

b)

Caudate

(head)

Caudate

(head)

V

E

N

T

R

A

L

CO

MPLE

X

V

E

N

T

R

A

L

CO

MPLE

X

B

a

so

la

te

r

a

l

co

m

p

le

x

B

a

so

la

te

r

a

l

co

m

p

le

x

FFornixornix

Primary olfactory cortexPrimary olfactory cortex

Lateral olfactory tractLateral olfactory tract

P

ar

ie

to

• o

cc

ip

it

al

s

ul

cu

s

P

ar

ie

to

• o

cc

ip

it

al

s

ul

cu

s

Ca

lca

rin

e (^) s
ul
cus
Ca
lca
rin
e (^) s
ul
cus
P
a
r
a
h
ip
p
o
c
a
m
p
a
l^
g
y
r
u
s
P
a
r
a
h
ip
p
o
c
a
m
p
a
l^
g
y
r
u
s
Occipital lobeOccipital lobe

C

or

ti

ca

lp

lat

e

C

or

ti

ca

lp

lat

e

White matterWhite matter

Globus pallidus

(internal

segment)

Globus pallidus

(internal

segment)

Globus pallidus

(external

segment)

Globus pallidus

(external

segment)

SUBSTANTIA

INNOMINATA

SUBSTANTIA

INNOMINAT A

Basal nucleus

of Meynert

Basal nucleus

of Meynert

Dentate

gyrus

Dentate

gyrus

Ammon's

horn

Ammon's

horn

Ammon's

horn

Ammon's

horn

Medullary laminaMedullary lamina

St

ri

at

er

m

in

ali

s

St

ri

at

er

m

in

ali

s

Damaged arDamaged areaea

Suprageniculate

nucleus

Suprageniculate

nucleus

Flocculus

(HX)

Flocculus

(HX)

Ansa lenticularis Ansa lenticularis

FimbriaFimbria

Auditory

radiation?

Auditory

radiation?

In

te

r

n

a

l

c

a

p

s

u

le

In

te

r

n

a

l

c

a

p

s

u

le

.tnI

ac

sp

ul

e

(p

os

te

ri

or

lim

b)

.tnI

ac

sp

ul

e

(p

os

te

ri

or

lim

b)

C

er

ebralped

u

n

c

le

C

er

ebralped

u

n

c

le

Lateral

ventricl e

Cor

ti

c

mo

e

d

ai

l

oc

m

p

el

x

A

M

Y

G

D

A

L

A

A

M

Y

G

D

A

L

A

Cor

ti

c

mo

e

d

ai

l

oc

m

p

el

x

R

E

T

I

C

U

L

A

R

B

E

LT

(R

et

ic

ul

ar

n

uc

le

us

)

R

E

T

I

C

U

L

A

R

B

E

LT

(R

et

ic

ul

ar

n

uc

le

us

)

Inferior

cerebellar

peduncle

Inferior

cerebellar

peduncle

Frontal

lobe

Frontal

lobe

Temporal

lobe

Te mporal

lobe

LayLayer er II

Stem cells of the

choroid plexus?

Stem cells of the

choroid plexus?

Alve ar glioepithelium

Amygdaloid glioepithelium/ependyma

Lateral migratory

stream

Lateral migratory

stream

Anterolateral striatal

neuroepithelium

and subventricular zone

Anterolateral striatal

neuroepithelium

and subventricular zone

Anteromedial striatal

neuroepithelium

and subventricular zone

Occipital neuroepithelium

and subventricular zone

Occipital stratified

transitional field

Pa rahippocampal neuroepithelium

and subventricular zone

Pa rahippocampal

stratified

transitional field

Fr ontal neuroepithelium and subventricular zone External germinal

layer

External germinal layer

Rostral

migratory

stream

(source area)

Callosal glioepithelium

Fornical

glioepithelium

Fo rnical

glioepithelium

Strionuclear glioepithelium

Subpial granular layer

Fr ontal stratified transitional field

Dentate

gyrus

Dentate

gyrus

Subgranular

zone

Subgranular

zone

Subgranular

zone

Subgranular

zone

Germinal and transitional structures in italics

PLATE 206B