The Human Brain During the Third Trimester

Germinal and transitional structuGerminal and transitional structurres ines in italicsitalics

External germinal layer

External germinal layer

CEREBELLUM

VVermisermis

HemispheHemispherree

F

ourth

ventricl

e

Lateral lemniscus

Mesencephalic nucleus (VMesencephalic nucleus (V))

Motor nucleus (VII)

Nerve V

Motor nucleus (V)

Medial longitudinal fasciculus

and tectospinal tract

Medial longitudinal fasciculus

and tectospinal tract

Dorsal longitudinal fasciculuDorsal longitudinal fasciculuss

Reticular Reticular ffo rmationormation

Transpontine corticofugal tract

Medial lemniscus, spinocephalic,

and trigemino-thalamic tracts

Pontine gray

Middle cerebellar peduncle

Pontocerebellar fibers (decussation)

Pontocerebellar fibers

Culmen

(IV-V)

Culmen

(IV-V)

Declive

(VI)

Declive

(VI)

Simplex lobule

(HVI)

Simplex lobu le

(HVI)

Centralis

(III)

Centralis

(III)

Anterior lobe

(HIV-HV )

Anterior lobe

(HIV-HV )

Raphe nuclear

complex

Raphe nuclear

complex

R

te

ci

lu

ra

te

gm

en

ta

ln

uc

le

us

R

te

ci

lu

ra

te

gm

en

ta

ln

uc

le

us

Parabrachial

nucleus

Parabrachial

nucleus

Principal sensory nucleus (V)

P O N SP O N S

Primary

fissure

Primary

fissure

Sup

eri

orce

rebellar

ped

un

Sup cle

eri

orce

rebellar

ped

un

cle

In

ferio

rcere

bellarpeduncle

In

ferio

rcere

bellarpeduncle

Middlecerebellar

peduncle

Middlecerebellar

peduncle

Dentate nucleuDentate nucleuss

Inter

positus

nucleu

s

Interpositu

s

nucleu

s

Fastigial

nucleus

Fa stigial

nucleus

Folium

(VIIa)

Fo lium

(VIIa)

Crus I,

ansiform lobule

(HVIIA)

Crus I,

ansiform lobu le

(HVIIA)

Mid

dle

cer

eb

el

lar

pe

du

nc

le

Mid

dle

cer

eb

el

lar

pe

du

nc

le

T

ear in sectio

n

T

ear in sectio

n

D

E

E

P

(^) N
U
C
L
E
I
D
E
E
P
(^) N
U
C
L
E
I
Pontine glioepithelium/
ependyma
Pontine glioepithelium/
ependyma
PLATE 145B