The Human Brain During the Third Trimester

3 5

6

7

Hippocampal

commissure

Cingulate gyrus

(retrosplenial area)

Superior frontal gyrus

Precentral

gyrus

Postcentral

gyrus

PrPrecuneusecuneus

HabenulHabenulaa

Central sulcus

Cingulate sulcus

Cingulate

sulcus (mar-

ginal part)

Cave of the septum

Subcallosal ar

ea

Subcallosal ar

ea

Orbital gyri

Gyrus

rectus

Gyrus

re ctus

Nucleus accumbenNucleus accumbenss

Olfactory tubeOlfactory tuberrclecle

TTectuectumm

TTe gmentumegmentum

GenuGenu

SpleniuSpleniumm

Olfactory bu lb

Anterior

commissure

Anterior

commissure

Optic nerve (II) and chiasm

Cerebral peduncle

Pontine gray

Transpontine corticofugal tract

Pyramid (corticospinal tract)

Inferior olive

Cuneate nucleus

Fourth ve ntricle

Cerebellar deep nuclei

Lateral ventricle

Cere bellum

(hemisphere )

Cingulate

gyr

us

Cingulate

gyr

us

MidbraiMidbrainn

ThalamusThalamus

PPonsons

M

edulla

M

edulla

Cerebellum

(vermis)

Cere bellum

(vermis)

Parietal

lobe

Parietal

lobe

Paracentral

lobule

Paracentral

lobu le

Hypo-

thalamus

Hypo-

thalamus

Sept

um

Sept

um

Frontal

lobe

Frontal

lobe

Frontal

lobe

Frontal

lobe

GW32 Sagittal

CR 270 mm

Y15-60

Level 2: Section 741

See detail of brain core and

cerebellum in Plates 103A and B.

Cingulate

gyrus

Cingulate

gyrus

Fo rnix

Fo rnix

Corpuscallos

um

Corpuscallos

um

2

Accumbent neuroepithelium and subventricular zone

(intermingled with the source of the rostral migratory stream)

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

10 External germinal layer (cerebellum)

8 Pontine glioepithelium/ependyma

9 Germinal trigone (cerebellum)

11 Subpial granular layer (cortical)

11

22

44

99

10

11

88

11

1 Rostral migratory stream

5 Fo rnical glioepithelium

7 Strionuclear glioepithelium

6 Septal glioepithelium/ependyma

4 Callosal glioepithelium

3 Callosal sling

Damaged areas in section

Cortical plate

White matter

Layer I

PLATE 97