Download The brain stem

The brain stem
SHANDONG UNIVERSITY
Liu Zhiyu
The brain stem
Consists of
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Midbrain
Pons
Medulla oblongata
The brain stem
Position
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The brain stem occupies
the posterior cranial fossa
of the skull
Gross Appearance of the Brain Stem
Ventral Surface of the Brain Stem
Medulla oblongata
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Pyramid:
Composed of bundles of nerve fiber,
pyramidal tract
Decussation of pyramid:
Formed by crossing fibers of pyramidal
tract
Olive:
Produced by underlying inferior olivary
nucleus
Anterolateral sulcus :
Emerge the roots of hypoglossal nerve
Retroolivary sulcus :
Emerge the roots of glossopharyngeal,
vagus and accessory nerves
Ventral Surface of the Brain Stem
Pons
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Basilar part
Basilar sulcus
Bulbopontine sulcus:
There emerge, from medial to lateral, the
abducent, facial and vestibulocochlear
nerves
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Middle cerebellar peduncle
Trigeminal nerve
Emerges from the junction of basilar part
and middle cerebellar peduncles
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Pontocerebellar trigone:
The junction of medulla, pons and
cerebellum
Ventral Surface of the Brain Stem
Midbrain
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Crus cerebri
Interpeduncular fossa
Oculomotor nerve emerges on the
medial side crus cerebri
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Posterior perforated substance
Dorsal Surface of the Brain Stem
Medulla oblongata
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Lower portion
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Gracile tubercle: produced by
underlying gracile nucleus
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Cuneate tubercle: produced by
underlying cuneate nucleus
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Inferior cerebellar peduncle
Obex
Upper portion: forms the lower half
of rhomboid fossa
Dorsal Surface of the Brain Stem
Pons
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Superior cerebellar peduncle
Superior medullary velum
Trochlear nerve
Dorsal Surface of the Brain Stem
Midbrain
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Superior colliculus
Constitute centers for visual reflexes
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Inferior colliculus
Associated with auditory pathway
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Brachium of superior colliculus
Brachium of inferior colliculus
Fourth ventricle
Central canal →fourth ventricle →mesencephalic aqueduct→third ventricle
Position
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Situated ventral to cerebellum,
and dorsal to pons and cranial
half of medulla
Floor of the Fourth ventricle —
Rhomboid Fossa
Boundaries
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Inferolateral: gracile and
cuneate tubercles, inferior
cerebellar peduncle
Superolateral: superior
cerebellar peduncle
Lateral recess
Floor of the Fourth ventricle —
Rhomboid Fossa
Features
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Median sulcus
Sulcus limitans
Vestibular area
Overlies vestibular nuclei
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Acoustic tubercle
Overlying dorsal cochlear nucleus
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Medial eminence
Striae medullares
Floor of the Fourth ventricle —
Rhomboid Fossa
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Facial colliculus
Overlies nucleus of abducent n. and
genu of facial nerve
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Hypoglossal triangle
Overlies hypoglossal nucleus
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Vagal triangle
Overlies dorsal nucleus of vagus
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nerve
Funiculus separans
Area postrema
Locus ceruleus
Bluish-gray in color, it owes its color to a
group of deeply pigmented nerve cells
Roof of the Fourth ventricle
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Anterior part:
Formed by superior cerebellar
peduncle and superior
medullary velum
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Posterior part:
Formed by inferior medullary
velum and choroid plexus of
fourth ventricle
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Three apertures
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Median aperture of fourth
ventricle
Two lateral apertures of fourth
ventricle
Tela choroidea and choroid plexus
Internal structure of the brain Stem
Internal structure of the brain Stem
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Central canal
Gray matter
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Cranial nerve nuclei
Relay nuclei
General somatic motor nuclei
Special visceral motor nuclei
General visceral motor nuclei
Visceral sensory nuclei ( general
and special )
General somatic sensory nuclei
Special visceral motor nuclei
White matter
Reticular formation of brain stem
Cranial nerve nuclei
General somatic motor nuclei
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Nucleus of oculomotor n.
Nucleus of trochlear n.
Nucleus of abducent n.
Nucleus of hypoglossal n.
General somatic motor nuclei
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Nucleus of oculomotor n.
Nucleus of trochlear n.
Nucleus of abducent n.
Nucleus of hypoglossal n.
General somatic motor nuclei
Nucleus
Site
Cranial n.
Function
Nucleus of
oculomotor n.
Midbrain
Ⅲ
Supreior, inferior,and
medial recti, inf. obliquus,
levator palpebrae superioris
Nucleus of
trochlear n.
Midbrain
Ⅳ
Superior obliquus
Nucleus of
abducent n.
Pons
Ⅵ
Lateral rectus
Medulla
Ⅻ
Muscles of tongue
Nucleus of
hypoglossal n.
Special visceral motor nuclei
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Motor nucleus of trigeminal n.
Nucleus of facial n.
Nucleus ambiguus
Accessory nucleus
Special visceral motor nuclei
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Motor nucleus of trigeminal n.
Nucleus of facial n.
Nucleus ambiguus
Accessory nucleus
Special visceral motor nuclei
Nucleus
Site
Cranial n.
Function
Motor nucleus of
trigeminal n.
Pons
Ⅴ
Masticatory muscles,
anterior belly of digastric,
mylohyoid
Nucleus of facial n.
Pons
Ⅶ
Facial m., platysma,
posterior belly of digastric,
stylohyoid, stapedius
Nucleus ambiguus
Medulla
Ⅸ,Ⅹ, Ⅺ
Accessory
nucleus
Medullacervical
cord
Ⅺ
Skeletal m. of pharynx,
larynx and upper part of
esophagus
Sternocleidomastoid,
trapezius
General visceral motor nuclei
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Accessory oculomotor nucleus
Superior salivatory nucleus
Inferior salivertory nucleus
Dorsal nucleus of vagus n.
General visceral motor nuclei
Nucleus
Site
Cranial n.
Function
Accessory
oculomotor nucleus
Midbrain
Ⅲ
Sphincter pupillae and
ciliary m.
Superior salivatory
nucleus
Pons
Ⅶ
Submandibular,
sublingual and lacrimal
glands
Inferior salivertory
nucleus
Medulla
Ⅸ
Parotid gland
Dorsal nucleus of
vagus n.
medulla
Ⅹ
Many cervical, thoracic
and abdominal viscera
Visceral sensory nuclei
( general and special )
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Nucleus of solitary tract
Visceral sensory nuclei
( general and special )
Nucleus
Nucleus of
solitary tract
Site
Cranial n.
Function
Medulla
Ⅶ,Ⅸ,Ⅹ
Taste and visceral
sensation
General somatic sensory nuclei
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Mesencephalic nucleus of
trigeminal n.
Pontine nucleus of trigeminal n.
Spinal nucleus of trigeminal n.
General somatic sensory nuclei
Nucleus
Site
Cranial n.
Function
Mesencephalic
Midbrain
nucleus of trigeminal n.
Ⅴ
Proprioception of head
Pontine nucleus of
trigeminal n.
Pons
Ⅴ
Tactile sensation of
head
Spinal nucleus of
trigeminal n.
Medulla
Ⅴ
Pain and temperature
sense of head
Special somatic sensory nuclei
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Cochlear nuclei
Vestibular nuclei
Special somatic sensory nuclei
Nucleus
Site
Cranial n.
Function
Pons and
medulla
Ⅷ
Sense of hearing
Vestibular nuclei Pons and
medulla
Ⅷ
Sense of equilibrium
Cochlear nuclei
Relay nuclei
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Superior colliculus
Nucleus of inferior colliculus
Red nucleus
Substantia nigra
Pretectal area
Superior olivery nucleus
Pontine nucleus
Nucleus ceruleus
Gracile nucleus
Cuneate nucleus
Inferior olivary nucleus
Non-cranial nerve nuclei
Nucleus
Site
Superior colliculus
Midbrain
Nucleus of inferior colliculus
Midbrain
Red nucleus
Midbrain
Substantia nigra
Midbrain
Pretectal area
Midbrain
Superior olivery nucleus
Pons
Pontine nucleus
pons
Nucleus ceruleus
pons
Gracile nucleus
Medulla (underneath gracile tubercle)
Cuneate nucleus
Medulla (underneath cuneate tubercle)
Inferior olivary nucleus
Medulla
White matter
Ascending tracts
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Medial lemniscus
Spinothalamic tract
（Spinal lemniscus ）
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Trigeminothalamic tract
（Trigeminal lemniscus ）
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Lateral lemniscus
Ascending tracts
Central thalamic
radiation
VPL
3°neurons
Medial lemniscus
Medial lemniscus
Gracile and cuneate nuclei
2°neuron
Decussation of medial lemniscus
Fasciculus cuneatus
T4
Spinal ganglion
1°neuron
Fasciculus gracilis
Ascending tracts
Spinothalamic tract
Central thalamic
radiation
VPL 3°neurons
（Spinal lemniscus）
Spinal lemniscus
anterior spinothalamic tract
LaminaⅠ,Ⅳ~Ⅶ
2°neuron
Spinal ganglia
1°neuron
Lateral spinothalamic tract
Ascending tracts
Trigeminothalamic tract
（Trigeminal lemniscus）
Pontine nucleus of V
2°neuron
Trigeminal ganglion
1°neuron
Spinal tract of trigeminal n.
Spinal nucleus of V
2°neuron
Central
thalamic
radiation
VPM
3°neurons
Trigeminal lemniscus
Ascending tracts
Lateral lemniscus
Descending tracts
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Pyromidal tract
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Corticospinal tract
Corticonuclear tract
Rubrospinal tract
Tectospinal tract
Vestibulospinal tract
Reticulospinal tract
Reticular Formation of Brain Stem
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Ascending reticular
activating system
(ARAS)
Motor central and
vital centres
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Reticulospinal tract
Cardiovascular center
Respiratory center
Serotonergic rapheal
nuclei
The characters of internal
structure of brain stem
Medulla oblongata
Lower part (closed part)
 Two decussations
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Decussations of medial lemniscus
Decussations of pyramid
Medulla oblongata
Upper part (open part)
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Appearance of inferior olivary
nuculeus and inferior cerebellar
peduncle
Enlargement of central canal to
form the fourth ventricle floor
Pons
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Tegmentum of pons
Directed upward continuation of
medulla oblongata
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Basilar part
Contain both longitudinal and
transverse fibers intermixed with
pontine nuclei
Midbrain
Rectum of midbrain
Includes superior and inferior colliculi
Cerebral peduncle
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Tegmentum
contain ascending tracts,
mesencephalic aqueduct, central gray
matter, recticular formation and so on
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Substentia nigra
Crus cerebri
 Pyramidal tract
middle three-fifths of the crus
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Frontopontine tract
medial one-fifth
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Pariatotempopontine tract
lateral one-fifth
Midbrain
Rectum of midbrain
Includes superior and inferior colliculi
Cerebral peduncle
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Tegmentum
contain ascending tracts, mesencephalic
aqueduct, central gray matter, red nucleus,
recticular formation and so on
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Substentia nigra
Crus cerebri
 Pyramidal tract
middle three-fifths of the crus
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Frontopontine tract
medial one-fifth
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Pariatotempopontine tract
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lateral one-fifth