The Human Brain During the Third Trimester

Cerebral

aqueduct

Cerebral

aqueduct

D

or

sa

lc

oc

hl

ea

r

nu

cl

eu

s?

D

or

sa

lc

oc

hl

ea

r

nu

cl

eu

s?

White matter

Cortical plate

Layer I

TTe mporal lobeemporal lobe

Subgranular zone

Strionuclear glioepithelium

Brachium of the

inferior colliculus

Optic nerve layer?

Superficial gray layer

Middle gray layer

Middle white layer

Deep gray layer

Deep white layer

Inferior cerebellar peduncle

and spinocerebellar tracts

External germinal layer

External

germinal layer

Molecular layer

Purkinje cell layer

Granule cell layer

Medullary layer

Arcuate nucleus (medulla, penetrated by raphe migration)

Py

ram

id

(co

rti

co

sp

ina

l

tra

ct)

Py

ram

id

(co

rti

co

sp

ina

l

tra

ct)

Lateral ve ntricle

Stratum oriens

Stratum pyramidale

Stratum radiatum

Stratum lacunosum moleculare

Dentate granular layer

Dentate molecular layer

Dentate hilus

SubiculuSubiculumm

Medial

longitudinal

fasciculus and

tectospinal

tract

Medial

longitudinal

fasciculus and

tectospinal

tract

R

a

hp

e^

n

u

lc

ea

r

c

o

m

lp

e

x

R

a

hp

e^

n

u

lc

ea

r

c

o

m

lp

e

x

Stria terminalis

Caudate (tail)

PONSPONS

MEDULLAMEDULLA

H

IP

P

O

C

A

M

P

U

S

H

IP

P

O

C

A

M

P

U

S

Dentate

gyrus

Dentate

gyrus

Para-

hippocampal

gyrus

Para -

hippocampal

gyrus

Superior

colliculus

Superior

colliculus

Central

gray

Central

gray

CA3CA3

CA1CA1

Reticular

formation

Reticular

fo rmation

Reticular

formation

Reticular

formation

Moto r

nucleus

(V)

Moto r

nucleus

(V)

Principal

sensory

nucleus

(V)

Principal

sensory

nucleus

(V)

Locus coeruleus

Mesencephalic

nucleus (V)

Moto r

nucleus

(VII)

Moto r

nucleus

(VII)

Subcom-

missural

organ

Subcom-

missural

organ

Inferior olive

complex

(principal nucleus)

Inferior olive

complex

(principal nucleus)

ANTERIOR LOBE

(HI-HV)

ANTERIOR LOBE

(HI-HV)

POSTERIOR

COMPLEX

(Pulvinar)

POSTERIOR

COMPLEX

(Pulvinar)

Middle

cerebellar

peduncle

Middle

cerebellar

peduncle

S

u

p

er

io

r

ce

r

eb

e

ll

a

r

p

e

d

u

n

cl

e

S

u

p

er

io

r

ce

r

eb

e

ll

a

r

p

e

d

u

n

cl

e

L

a

te

r

a

l

le

m

n

is

c

u

s

L

a

te

r

a

l

le

m

n

is

c

u

s

M

ed

ia

l

le

m

n

si

cu

s

M

ed

ia

l

le

m

n

si

cu

s

Nerve IV root?

Spinal

nucleus

(V)

Spinal

nucleus

(V)

Medial

accessory

olive

Medial

accessory

oliv e

Inferior

colliculus

Inferior

colliculus

Central

nucleus

Central

nucleus

Ventral

cochlear

nucleus

Ve ntral

cochlear

nucleus

Fourth

ventricl e

C

e

n

tr

a

l

g

r

a

y

C

e

n

tr

a

l

g

r

a

y

R

E

T

IC

U

LA

RBELT

(R

et

ic

ul

ar

n

uc

le

u

s)

R

E

T

IC

U

LA

RBELT

(R

et

ic

ul

ar

n

uc

le

u

s)

THALAMUSTHALAMUS

F

im

b

ri

a

F

im

b

ri

a

FimbriFimbriaa

HEMISPHEREHEMISPHERE

CEREBELLUMCEREBELLUM

Pa

rabr

ac

hi

a

nl

cu

el

su

Pa

rabr

ac

hi

a

nl

cu

el

su

Simplex

lobule

(HVI)

Simplex

lobu le

(HVI)

Part of

section

torn away

ISTHMUSISTHMUS

Spinocephalic tract?

Choroid

plexus

Choroid

plexus

Isthmal and pontine

glioepithelium/ependyma

Isthmal and pontine

glioepithelium/ependyma

Te mporal neuroepithelium

and subventricular zone

Te mporal stratified

transitional field

Po sterior striatal neuroepithelium

and subventricular zone

Pa rahippocampal stratified

transitional field

Pa rahippocampal neuroepithelium

and subventricular zone

Alve ar glioepithelium

TECTUMTECTUM

MIDBRAIMIDBRAINN

Mesencephalic

glioepithelium/

ependyma

Mesencephalic

glioepithelium/

ependyma

Germinal and transitional

structures in italics

Germinal and transitional

structures in italics

Fi mbrial

glioepithelium

Paramedian

lobule

(HVIIB)

Paramedian

lobu le

(HVIIB)

Raphe migration

PLATE 186B

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