The Human Brain During the Third Trimester

Spinocerebellar tracts

Cuneate

fasciculus

Gracile

fasciculus

Floccular

peduncle

Spinocephalic tract?

External germinal layer

External germinal layer

Germinal

trigone

Germinal

trigone

Molecular layer

Purkinje cell layer

Granule cell layer

Medullary layer

Medial longitudinal fasciculus

and tectospinal tract

Cuneate

nucleus

Cuneate

nucleus

Reticular

formation

Reticular

formation

Central auto-

nomic area

Central auto-

nomic area

Accessory nucleus (XI)

Spinal

nucleus

and tract

(V)

Spinal

nucleus

and tract

(V)

Fourth

ventricl e

MEDULLAMEDULLA

Culmen

(IV-V)

Culmen

(IV-V)

Centralis

(III)

Centralis

(III)

Uvula?

(IX)

Uvula?

(IX)

Nodulus

(X)

Nodulus

(X)

Nodulus

(X)

Nodulus

(X)

Simplex lobule

(HVI)

Simplex lobu le

(HVI)

Paramedian

lobule

(HVIIB)

Paramedian

lobu le

(HVIIB)

Biventral

lobule

(HVIII)

Biventra l

lobu le

(HVIII)

Choroid

plexus

Choroid

plexus

Choroid

plexus

Choroid

plexus

C

E

R

E

B

E

L

L A R D E E P N U C L E I

C

E

R

E

B

E

L

L A R D E E P N U C L E I

Dentate

nucleus

Dentate

nucleus

Inter

positus

nucleus

Interpositus

nucleus

Fastigial

nucleus

Fa stigial

nucleus

Middle

cerebellar

peduncle

Middle

cerebellar

peduncle

ANTERIOR LOBE?

(HI-HV)

ANTERIOR LOBE?

(HI-HV)

Part of

section

torn away

Raphe nuclear complex

Area

postrema

Commissural

nucleus (X)

Central canal (medulla/spinal cord)

Spinomedullary glioepithelium/ependyma

Pyramid (corticospinal tract)

Pyramidal decussation

Ansiform lobule

Crus II

(HVIIA)

Ansiform lobu le

Crus II

(HVIIA)

Ansiform lobule

Crus I

(HVIIA)

Ansiform lobu le

Crus I

(HVIIA)

VERMISVERMIS

HEMISPHEREHEMISPHERE

CEREBELLUMCEREBELLUM

Germinal and transitional structures in italics

PLATE 189B