The Human Brain During the Third Trimester

GW26 Sagittal

CR 225 mm

Y147-63

Level 1: Section 501

Pineal gland

Chor

oid plexu

s

Chor

oid plexu

s

Nerve IV root?

Basal pontine gray

Optic chiasm

Olfactory bu lb and peduncle

Transpontine corticospinal tract

Oculomotor nerve(III)

Superior cerebellar

peduncle

Primary fissure

Pyramid (corticospinal tract)

Pyramidal decussation

Inferior olive complex

Raphe

nuclear

complex

Raphe

nuclear

complex

Posterior commissure

Anterior

commissure

Cerebral peduncle

Medial longitudinal fasciculus

and tectospinal tract

Gracile faciculus and nucleus

C

av

e^ o

f^ t

he

se

pt

um

Fo

rn

ix

Fo

rn

ix

Gyrus Gyrus rrectuectuss

Subcallosal

area

Subcallosal

area

Parietal

lobe

Parietal

lobe

Frontal

lobe

Frontal

lobe

Frontal

lobe

Frontal

lobe

Hypo-

thalamus

Hypo-

thalamus

Preoptic

area

Preoptic

area

GenuGenu

Sp

le

ni

um

Sp

le

ni

um

S

ep

tu

m

S

ep

tu

m

TTectuectumm

MidbraiMidbrainn

PPonsons

MedullaMedulla

Spinal cordSpinal cord

Occipital

lobe

Occipital

lobe

Cortical plate

White matter

Layer I

Third

ventricle

Fourth

ventricle

Fourth

ventricl e

Interpeduncular

nucleus

Interpeduncular

nucleus

Cere bellum

(vermis)

Anterior

lobe

Anterior

lobe

Central

lobe

Central

lobe

Posterior

lobe

Po sterior

lobe

Inferior

lobe

Inferior

lobe

TTe gmentumegmentum

Inferior

colliculus

Inferior

colliculus

Superior

colliculus

Superior

colliculus

11

22

33

44

55

66

77

11

3 Diencephalic/mesencephalic glioepithelium/ependyma

2 Diencephalic glioepithelium/ependyma

6 Precerebellar glioepithelium

C

or

pu

sc

allo

sum

C

or

pu

sc

allo

sum

Hippocampal

commissure?

Remnants of the germinal matrix, migratory streams, and transitional fields

4 Mesencephalic glioepithelium/ependyma External germinal layer (cerebellum)

10

1 Rostral migratory stream

5 Pontine glioepithelium/ependyma

7 Medullary glioepithelium/ependyma

8 Raphe migration

9 Germinal trigone (cerebellum)

10

10

11

11

11

9

8

11 Subpial granular layer (cortical)

See detail of brain core and

cerebellum in Plates 200A and B.

Damaged areas in section

PLATE 190