The Human Brain During the Third Trimester

V

entral cochlear

nucleus

Brachium of the inferior colliculus

Central nucleus

Inferior cerebellar peduncle

and spinocerebellar tracts

External germinal layer

Germinal trigone

(continuous with stem cells

of the choroid plexus)

External germinal layer

Molecular layer

Purkinje cell layer

Granule cell layer

Medullary layer

Pyramid

(corticospinaltract

Pyramid)

(corticospinaltract

)

Medial

longitudinal

fasciculus and

tectospinal

tract

Medial

longitudinal

fasciculus and

tectospinal

tract

Reticular

formation

Reticular

fo rmation

Reticular

formation

Reticular

formation

Lateral

reticular

nucleus

Lateral

reticular

nucleus

Nucleus

ambiguus?

Nucleus

ambiguus?

Dorsal

accessory

olive

Dorsal

accessory

oliv e

Inferior olive

complex

(principal nucleus)

Inferior olive

complex

(principal nucleus)

A

N

T

E

R

IO

R

L

O

B

E

(H

I-H

V

)

A

N

T

E

R

IO

R

L

O

B

E

(H

I-H

V

)

Middle

cerebellar

peduncle

Middle

cerebellar

peduncle

M

e

d

ia

l

le

m

n

is

cu

s

M

e

d

ia

l

le

m

n

is

cu

s

Spinal

nucleus

and tract

(V)

Spinal

nucleus

and tract

(V)

V

entral cochlear

nucleus

Fourth

ventricl e

Flocculus

(HX)

Flocculus

(HX)

MEDULLAMEDULLA

PONSPONS

VERMIS

Lingula

(I, II)

Lingula

(I, II)

Centralis

(III)

Centralis

(III)

MIDBRAIN TECTUM

(Inferior colliculus)

MIDBRAIN TECTUM

(Inferior colliculus)

Pre-

positus

nucleus

Pre-

positus

nucleus

Medial

vestibular

nucleus

Medial

vestibular

nucleus

Superior

vestibular

nucleus

Superior

vestibular

nucleus

Lateral

vestibular

nucleus?

Lateral

vestibular

nucleus?

Inferior

vestibular

nucleus

Inferior

vestibular

nucleus

Superior

cerebellar

peduncle

Superior

cerebellar

peduncle

Parabrachial

nucleus

Cerebellar

dentate nucleus

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

Vestibular

nuclear

complex

Ve stibular

nuclear

complex

Inferior

cerebellar

peduncle

Inferior

cerebellar

peduncle

Simplex

lobule

(HVI)

Simplex

lobu le

(HVI)

Paramedian

lobule

(HVIIB)

Paramedian

lobu le

(HVIIB)

Biventral

lobule

(HVIII)

Biventra l

lobu le

(HVIII)

Dorsal

longitudinal

fasciculus

Dorsal

longitudinal

fasciculus

Choroid

plexus

Choroid

plexus

Ansiform lobule

Crus II

(HVIIA)

Ansiform lobu le

Crus II

(HVIIA)

Part of

section

torn away

Part of

section

torn away

Spinocephalic tract?

Ansiform lobule

Crus I

(HVIIA)

Ansiform lobu le

Crus I

(HVIIA)

HEMISPHEREHEMISPHERE

CEREBELLUMCEREBELLUM

Germinal and transitional structures in italics

Pontine and medullary

glioepithelium/

ependyma

Pontine and medullary

glioepithelium/

ependyma

PLATE 187B