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Department of Anatomy
Brain stem
MUDr. Marek Joukal, Ph.D.
BRAIN STEM
medulla oblongata
pons Varoli
mesencephalon
Medulla oblongata
•Continuation of the spinal cord (20–25mm)
((bulbus medullae spinalis)
• from the C1 spinal nerves
(decussatio pyramidum) to the pons Varoli
• sulcus bulbopontinus (VI., VII., VIII.)
• fissura mediana anterior
(foramen caecum)
• sulcus lateralis anterior (XII.)
• sulcus lateralis posterior (IX., X., XI.)
• sulcus medianus posterior
• pyramis et oliva medullae oblongatae
Dorsal side of the medulla oblongata
(inferior part of the fossa rhomboidea)
sulcus medianus posterior
sulcus intermedius posterior
faciculus gracilis – clava (tuberculum ncl. gracilis)
fasciculus cuneatus – tuberculum cuneatum
tuberculum cinereum
pedunculi cerebellares inferiores
tenia ventriculi quarti
tela choroidea ventriculi quarti
Pons Varoli
Between the medulla oblongata and the mesencephalon
(25 – 30 mm)
sulcus basilaris (a. basilaris)
sulcus bulbopontinus
VI. – nervus abducens
VII. – nervus facialis
VIII. – nervus vestibulocochlearis
pedunculi cerebellares medii
V. – nervus trigeminus
Lateral side of the pons Varoli
pedunculus cerebellaris medius
nervus trigeminus
angulus pontocerebellaris
trigeminofacial line
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Dorsal side of the pons Varoli
pars intermedia fossae rhomboidae
pedunculi cerebellares medii
stria medullaris
sulcus medianus
sulci limitantes
eminentia medialis
colliculus facialis (n. VI.)
recessus lateralis
area vestibularis
tuberculum acusticum
Mesencephalon mozek)
between pons Varoli and diencephalon
(app 30 mm)
pedunculi (crura) cerebri
fossa interpeduncularis
substantia perforata posterior
(arteriae centrales post.)
sulcus nervi oculomotorii
n. III. (nervus oculomotorius)
Dorsal side of the mesencephalon
corpora quadrigemina (lamina tecti)
colliculi superiores
(optico-motor reflexes)
colliculi inferiores
(acustico–motor reflexes)
brachium colliculi sup. (visual pathway)
brachium colliculi inf. (auditory pathway)
pedunculi cerebellares superiores
velum medullare superius
frenulum veli medullaris superioris
n. IV. – nervus trochlearis
Fossa rhomboidea
Floor of the 4th ventricle (doral side of the brain stem)
1. pars superior (mesencephalon)
2. pars intermedia (pons Varoli)
3. pars inferior (medulla oblongata)
between pedunculi cerebellares inf.
striae medullares
sulcus medianus
sulci limitantes (eminentia medialis)
trigonum nervi hypogloossi
trigonum nervi vagi (fovea inferior)
Pars superior
fovea superior (n. V.)
locus coeruleus
Pars intermedia
stria medullaris, recessus lat.
colliculus facialis (n. VI.)
area vestibularis
tuberculum acusticum
Pars inferior
trigonum nervi hypogloossi
trigonum nervi vagi (fovea inferior)
Fossa rhomboidea
Alar plate – zones:
somatosensory
viscerosensory
Basal plate - zones:
somatomotori
(branchiomotor)
visceromotor
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1 - ncl. motorius (originis) n. III.
2 - ncl. motorius (originis) n. IV.
3 - ncl. motorius (originis) n. VI.
4 - ncl. motorius (originis) n. XII.
5 - ncl. motorius (originis) n. VII.
6 - ncl. motorius (masticatorius) n. V.
7 - ncl. motorius (originis) n. IX
8 - ncl. parasympathicus n. III (ncl. E.W.)
9 - ncl. parasympathicus n. VII.
10 - ncl. parasympathicus n. IX.
11- ncl. parasympathicus n. X.
12 - ncl. solitarius (n. VII, n. IX., n. X.,)
13 - ncl. spinalis n. V. (n. VII, n. IX., n. X.,)
14 - ncl. principalis n. V.
15 - ncl. mesencephalicus n. V.
16 - ncll. cochleares et vestibulares
Cranial nerve nuclei on the floor of the 4th ventricle Somatosensory zone
ncl. gracilis + ncl. cuneatus med. (epikritic, discriminative sensation)
ncl. cuneatus lat. (proprioception UE)
ncl. tractus spinalis n. V. (protopatic sensation)
Viscerosensory zone
ncl. tractus solitarii (ncl. gustatorius) – n. VII., n. IX., n. X.
Visceromotor zone
ncl. parasympatikus n. X.
Branchiomotor zone
ncl. ambiguus (n. IX., n. X., n. XI.)
Somatomotor zone
ncl. originis n. XII.
Medulla oblongata – caudal cross-section
Sensory zone
fasciculus gracilis + fasciculus cuneatus
fibrae arcuatae infernae – decussatio lemniscorum – lemniscus med.
tractus spinalis n. V.
tr. spino-cerebellaris ant. + post.
Viscerosensory zone
tractus solitarii – n. VII., n. IX., n. X.
Somatomotor zone
Pyramidal t. decussatio pyramiduum – tr. cortico-spinalis ant. + lat.
extrapyramidal tracts
tr. rubro-spinalis, reticulo-spinalis, vestibulo – spinalis, tecto – spin.
FLM, RF
Medulla oblongata – caudal cross-section Medulla oblongata – rostral cross-section
Somatomotor zone – ncl. originis n. XII.
Branchiomotor zone – ncl. ambiguus (n. X.)
Visceromotor zone – ncl. parasympatikus n. X.
Viscerosensory zone – ncl. tractus solitarii – n. X.
Somatosensory zone
ncl. cuneatus lat. (propr. UE)
ncl. tractus spinalis n. V.
Sensory zone
nccl. vestibulares
Interneurons – ncll. olivares inf.
RF
Medulla oblongata – rostral cross-section Tracts:
Pedunculus cerebellaris inf.
tr. spino.cerebellaris post.
tr. olivo-cerebellaris
tr. cuneo-cerebellaris
tr. vestibulo-cerebellaris
Sensory tracts
lemniscus medialis
tr. spino-cerebellatis ant.
Motor tracts:
tr. cortico-spinal., rubro-spin., vestibulo-spin.,
tecto-spin.
FLM, FLD
tr. tecto-spin.
tr. rubro-spin.
tr. vestibulo-spin.
FLM
FLD
Pons Varoli – caudal cross-section Somatomotor zone – ncl. originis (motorius) n. anducentis
Branchiomotor zone – ncl. motorius n. VII.
Visceromotor zone – ncl. parasympaticus n. VII.
Viscerosensory zone – ncl. tr. spinalis (sensorius principalis) n. V.
Somatosensory zone – ncl. cuneatus lat.
Sensory zone – ncll. vestibulares
ncll. cochleares
White matter – sensory tracts
tr. spino-cerebellaris ant., lemniscus med., lemniscus lat.,
Pedunculus cerebellaris medius
tractus cortico-ponto-cerebellares (ncll. Pontis)
Motor tracts:
tr. cortico-spinal. (fasciculi longitudinales),
rubro-spin., tecto-spin.
LM
LL
FLM
FLD
tr. tecto-spin. tr. rubro-spin.
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Pons Varoli – rostral cross-section
FLD
FLM
tr. tecto-spin.
LM
LL
tr. rubro-spin.
cortico-bulb.
tr. spino-cereb. ant.
Branchiomotor zone
ncl. motorius n. V (ncl. masticatorius)
Somatosensory zone
ncl. tr. mesencephalicus n. V
sensorius principalis n. V
tr. spino-cerebellaris ant., lemniscus med., lemniscus
lat.,
Pedunculus cerebellaris medius
tractus cortico-ponto-cerebellares
(ncll. pontis)
Motor tracts:
tr. cortico-spinal. (fasciculi longitudinales),
rubro-spin., tecto-spin.
Tectum
(alar plate)
Tegmentum
(basal plate)
Crura cerebri
Transverse cross-section through the mesencephalon
ventral
dorsálně
Mesencephalon – caudal cross-section Somatomotor zone – ncl. motorius n. IV
Sensory ncll. and tracts
ncl. tr. mesencephalicus n. V
tr. spino-cerebellaris ant., lemniscus med., lemniscus lat.,
Other gray matter
substantia nigra (pars reticularis, pars compacta - dopamin)
ncl. colliculi inf.
Motor tracts:
rubro-spin., tecto-spin.
tr. cortico-spinal.
tr. cortico- nucleares
tractus cortico-ponto-cerebellares (ncll. pontis)
FLD
FLM
tr. tecto-spin.
ncl. interpedun.
tr. rubro-spin. tr. cortico-
spin.
tr. cortico-ncll.
tr. cortico-ncll.
tr. fronto-ponto-cerebellaris
tr. parieto-
temporo
-occipito-ponto
-cerebellaris
Mesencephalon – rostral cross-section Somatomotor zone – ncl. motorius n. III
Visceromotor zone – ncl. parasympaticus n. III (Ed-W)
Somatosensory ncl. – ncl. tr. mesencephalicus n. V
Other gray matter – area praetectalis (pupilar reflexes)
ncl. colliculi sup. (visual pathway, optico-motor reflexes)
substantia nigra + ncl. ruber (motor circuits)
ncl. interpeduncularis (limbic system)
Tracts
lemniscus med., lemniscus lat.,
tractus cortico-ponto-cerebellares
tr.rubro-spin., tr. tecto-spin.
tr. tegmentalis centralis (visceromotor)
FLD
tr. rubro-spin.
tr. tecto-spin.
Fasciculus longitudinalis medialis
Bundle of axons
from nucleus intersticialis and Darkshevich
(ncll. oculomotorii accesorii)
To the motor ncll. III. IV. and VI. and vestibular
ncll.
Coordination of the head and neck movements
with eye movemnts and vestibular app.
Fixation of moving point
Reticular formation
a set of gray matter permeated by white matter (net-like)
Interneurons and their connections – between aferent and
motor system
location: C spinal cord – diencephalon
Nuclei of the RF
middle, rafeal group
medial (paired)
lateral
cerebellar
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Function of the Reticular Formation
Activatory and inhibitory function of the CNS (ARAS – regulation of sleeping)
connection and corrdination of appropriate parts of the CNS
Centre of reflexes
(life centers – heart action, breathing, suction reflex, defense reflexes – cough,
vomitting…)
carries phyllogenetically old information (mainly visceral)
Influence on nociceptive information (pain)
neurosecretion
References
Dubový, P., Jančálek, R.: Základy neuroanatomie a nervových drah I. Masarykova univerzita Brno, 2013
Dokládal, M., Páč, L.: Anatomie člověka III. Masarykova univerzita v Brně, 1995.
Čihák, R.: Anatomie 3. Praha, Grada, 2001, 2004
Sobotta, J.: Atlas of Human Anatomy Vol1 –2 Munich, Urban und Schwarzenberg, 1993
Páč, L., Vargová, L., Čuta, M. : Anatomie pro antropology III. Nadace universitas, Akademické nakladatelství
CERM. Masarykova univerzita 2013.
Wiliams, P. & Warvick, R.: Gray´s Anatomy, 37 ed, Churhill Livingstone, 1996
Netter, F.:Atlas of Human Anatomy, 4th ed., Elseviesr, USA, 2006