The Human Brain During the Third Trimester

S

ol

it

ar

y

n

uc

le

u

s

an

d

(^) t
ra
ct

S

ol

it

ar

y

n

uc

le

u

s

an

d

(^) t
ra
ct
Cuneate
nucleus
Cuneate
nucleus
Cun
eate
nuc
leus
Cun
eate
nuc
leus
Dorsal sensory
nucleus (X)
Dorsal sensory
nucleus (X)
Central canal
(medulla/spinal cord)
Central canal
(medulla/spinal cord)
Central canal
(medulla/spinal cord)
Central canal
(medulla/spinal cord)

D

o

rs

al

m

ot

or

n

u

cle

us

(^) (X
)

D

o

rs

al

m

ot

or

n

u

cle

us

(^) (X
)
Hypoglossa
l
nucleus (XII)Hypoglossa
l
nucleus (XII)
Inferior olive
(principal nucleus)
Inferior olive
(principal nucleus)
Medial accessory
olive nucleus
Medial accessory
olive nucleus
Medial longitudinal fasciculus
and tectospinal tract
Medial longitudinal fasciculus
and tectospinal tract
Medial longitudinal fasciculus
and tectospinal tract
Medial longitudinal fasciculus
and tectospinal tract
Reticular
formation
Reticular
fo rmation
Reticular
formation
Reticular
fo rmation
Raphe nuclear compleRaphe nuclear complexx
Spinal nucleus
and tract (V)
Spinal nucleus
and tract (V)
Spinal nucleus
and tract (V)
Spinal nucleus
and tract (V)
LO WER MEDULLA
Section 1281
Section 1351
Section 139 1
MEDULLA/
SPINAL CORD
MEDULLA/
SPINAL CORD
External cuneate nucleus
Spinocerebellar tracts
Spinocerebellar tracts
Spinocephalic tract
Spinocephalic tract
Spinocerebellar tracts
Lissauer's tract
Spinocephalic tract
Motoneuron columns
(spinal cord)
Medial lemniscuMedial lemniscuss
Pyram
id
Pyram
id
(corticospinal
tract)
Pyram
id
Pyram
id
(corticospinal
tract) P
y
ra
m
id

P

y

ra

m

id

(c

o

r

ti

c

o

sp

in

a

l

tr

a

ct

)

P

y

ra

m

id

P

y

ra

m

id

(c

o

r

ti

c

o

sp

in

a

l

tr

a

ct

)

P

y

r

a

m

id

P

y

r

a

m

id

(c

o

r

ti

co

sp

in

a

l

tr

a

ct

)

P

y

r

a

m

id

P

y

r

a

m

id

(c

o

r

ti

co

sp

in

a

l

tr

a

ct

)

Gracile

nucleus

Gracile

nucleus

Gracile

nucleus

Gracile

nucleus

Gracile

nucleus

Gracile

nucleus

Cu

ne

at

e

fa

sc

ic

u

lu

s

Cu

ne

at

e

fa

sc

ic

u

lu

s

Commissural

nucleus (X)

Commissural

nucleus (X)

G

ra

ci

le

fa

sc

ic

u

ul

s

G

ra

ci

le

fa

sc

ic

u

ul

s

Lateral

reticular

nucleus

Lateral

reticular

nucleus

Lateral

reticular

nucleus

Lateral

reticular

nucleus

Dorsal motor nucleus (XDorsal motor nucleus (X))

Hypoglossal nucleus (XII)Hypoglossal nucleus (XII)

Accessory nucleus (XI)Accessory nucleus (XI)

Cuneate

fasciculus

Cuneate

fasciculus

Cuneate

fasciculus

Cuneate

fasciculus

Gracile

fasciculus

Gracile

fasciculus

Gracile

fasciculus

Gracile

fasciculus

Central

cervical

nucleus

Central

cervical

nucleus

Central

autonomic

area

Central

autonomic

area

Lateral

cervical

nucleus

Lateral

cervical

nucleus

Later

corti al

cospi

tr nal

act

Later

corti al

cospi

tr nal

act

Substantia

gelatinosa

Substantia

gelatinosa

Py

ra

m

id

al

decu

ssa

tio

n

Py

ra

m

id

al

decu

ssa

tio

n

Medial longitudinal

fasciculus and

tectospinal tract

Spina

ltra

ct(

V

)

Spina

ltra

ct(

V

)

Central canal

(medulla/spinal cord)

Germinal and transitional structuGerminal and transitional structurres ines in italicsitalics

Dorsal funicular

myelination gliosis

Dorsal funicular

myelination gliosis

Ve ntral funicular

myelination gliosis

Glioepithelium/ependymaGlioepithelium/ependyma

Glioepithelium/ependymaGlioepithelium/ependyma

Glioepithelium/ependymaGlioepithelium/ependyma

*Arcuate nucleus
(medulla)

*Arc uate nucleus
(medulla)

*Arc uate nucleus

(medulla)

*The arcuate nucleus in the medulla

may contain neurons

from the Raphe migration.

PLATE 150B