The Human Brain During the Third Trimester

Abducens

nucleus (VI)?

Abducens

nucleus (VI)?

L

a

te

ra

l^

ve

n

tr

ic

le

L

a

te

ra

l^

ve

n

tr

ic

le

Temporal

lobe

Te mporal

lobe

C

hor

oid plexus

C

hor

oid plexus

CA1CA1

InterInternal capsulnal capsulee CA3CA3

Cerebral

aqueduct

Cere bral

aqueduct

Central

gray

Central

gray

Central

nucleus

Central

nucleus

Medial

longitudinal

fasciculus

Medial

longitudinal

fasciculus

Su

pe

ri

or

c

er

eb

el

la

r

pe

du

nc

le

?

Su

pe

ri

or

c

er

eb

el

la

r

pe

du

nc

le

?

Central

tegmental

tract

Central

tegmental

tract

Tecto-

spinal

tract

Tecto-

spinal

tract

F

im

br

ia

F

im

br

ia

Reticular

formation

Reticular

formation

Lateral

lemniscus

Lateral

lemniscus

Mesencephalic

nucleus (V)

Nucleus of the lateral

lemniscus (ventral)

Dorsal

tegmental

nucleus

Dorsal

tegmental

nucleus

Parabrachial

nucleus

Parabigeminal

nucleus (ventral)

Superior

olive

Superior

oliv e

Inferior olInferior olivivee

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

)

Trigeminal

moto r

nucleus?

Trigeminal

moto r

nucleus?

Trochlear

nucleus (IV)

Tr ochlear

nucleus (IV)

Nerve VIII

Nerve V (root, with myelination gliosis)

Trapezoid body (intermingled

with medial lemniscus)

Pontine

gray

Pontine

gray

A

m

m

o

n

's

h

or

n

A

m

m

o

n

's

h

or

n

Subi

cu

lu

m

Subi

cu

lu

m

P

re

su

b

ic

u

ul

m

P

re

su

b

ic

u

ul

m

Superior

colliculus

Superior

colliculus

Inferior

colliculus

Inferior

colliculus

Zonalla

ye

r

Zonalla

ye

r

O

pt

ic

ne

rvela

yer

O

pt

ic

ne

rvela

yer Superficialgra

y

la

ye

r

Sup

erficialgr

ay

la

ye

r

M

id

dle

gray

layer

M

id

dle

gray

layer

Middlew

hit

el

ay

er

Middlew

hit

el

ay

er

D

ee

p

gra

yla

yer

D

ee

p

gra

yla

yer

Deepw

hite

lay

er

Deepw

hite

lay

er

M

e

d

ia

l

el

m

n

is

cu

s

M

e

d

ia

l

el

m

n

is

cu

s

Granular laGranular layeyerr

Molecular laMolecular layeyerr

Pyramidal laPyramidal layeyerr

Stratum orienStratum orienss

Stratum radiatumStratum radiatum

Stratum lacunosum-

moleculare

Stratum lacunosum-

moleculare

HilusHilus

HippocampusHippocampus

Brachium of the

inferior colliculus

Raphe nuclear complex

PONSPONS

MIDBRAIMIDBRAINN

MEDULLAMEDULLA

Subgranular

zone

Subgranular

zone

Subgranular

zone

Subgranular

zone

D

ent

a

t

e

gy

ru

s

D

ent

a

t

e

gy

ru

s

D

e

n

ta

te

gyru

s

D

e

n

ta

te

gyru

s

R

a

p

h

e^

n

u

c

le

a

r

c

o

m

p

le

x

R

a

p

h

e^

n

u

c

le

a

r

c

o

m

p

le

x

Corticospinal

(pyramidal) tract

Corticospinal

(pyramidal) tract

External germinal layer

Molecular layer

Granular layer

Medullary layer

Hippocampal CommissuHippocampal Commissurree

FFo rnical glioepitheliuornical glioepitheliumm

Germinal and transitional structuGerminal and transitional structurres ines in italicsitalics

TTectuectumm

TTe gmentumegmentum

Mesencephalic

glioepithelium/ependyma

Mesencephalic

glioepithelium/ependyma

Inferior cerebellar

peduncle

Middle

cerebellar

peduncle

HemispheHemispherree

CEREBELLUMCEREBELLUM

Temporal stratified

transitional field

Te mporal stratified

transitional field

Temporal neuro-

epithelium and

subventricular

zone

Te mporal neuro-

epithelium and

subventricular

zone

Pa rahippocampal neuroepithelium,

subventricular zone, and

stratified transitional field

AlvAlve ar glioepitheliuear glioepitheliumm

Subpial granular layer

HHIPPOIPPOCCAAMMPUPUSS

Parahippocampal

gyrus

Parahippocampal

gyrus

PLATE 41B