Section 2 The Brain (Encephalon) (?)

1
Section 2 The Brain (Encephalon) (?)

• THE BRAIN STEM (??)
• THE CEREBELLUM
• (??)
• THE DIENCEPHALON
• (??)
• THE TELENCEPHALON (??)
• Average Total Weight 1400 g

2
A. Divisions of Brain (????)
Early embryo (????)
Late embryo (????)
Adult (??)
telencephalon (??)
cerebrum (??)
forebrain (??) (prosencephalon)
diencephalon (??)
diencephalon (??)
midbrain (??) (mesencephalon)
mesencephalon (??)
midbrain (??)
cerebellum (??)
metencephalon (??)
hindbrain (??) (rhombencephalon)
pons (??)
myelencephalon (??)
medulla oblongata(??)
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B. Brain Stem (??)
1. ? Subdivision of the brain stem

• 1) medulla oblongata (bulb) (??)
• 2) pons (??)
• 3) midbrain (??)
• 4) rhomboid fossa
• (???)

4
B. Brain Stem (??)
1. ? Subdivision of the brain stem
1) medulla oblongata (bulb) (??) 2) pons
(??) 3) midbrain (??) 4) rhomboid fossa
(???)
5
B. Brain Stem (??)
? 2. External features (??)

• ? 1) medulla oblongata (bulb) (??)
• a. anterior median fissure (????)
• b. pyramid (??)
• c. decussation of pyramid (????)
• d. anterolateral sulcus (????) - XII

6
B. Brain Stem (??)
e. olive (??) - dorsal - IX, ?, XI f.
bulbopontine sulcus (?????) -VI,VII,VIII
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B. Brain Stem (??)

• g. posterior median sulcus (????)
• h. gracile tubercle
• (????)
• i. cuneate tubercle (????)
• j. obex (?)
• k. inferior cerebellar peduncle (????)

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B. Brain Stem (??)

• ? 2) pons (??)
• a. basilar part (???) - V
• b. basilar sulcus (???)

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B. Brain Stem (??)
c. middle cerebellar peduncle (????) d.
pontocerebeller trigone (??????) e. superior
cerebellar peduncle (????) f. superior medullary
velum (???)
d
10
B. Brain Stem (??)

• ? 3) midbrain (??)
• a. crus cerebri (???)
• b. interpeduncular fossa (???) - III
• c. posterior perforated substance (???)

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B. Brain Stem (??)
d. superior colliculus (??) e. brachium of
superior colliculus (???) f. inferior colliculus
(??) - IV g. brachium of inferior colliculus (???)
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B. Brain Stem (??)
? 4) rhomboid fossa (???) (floor of the 4th
ventricle ?????)

• a. median sulcus (???)
• b. sulcus limitans (??)
• c. locus ceruleus
• (??)
• d. striae medullares (??)

13
B. Brain Stem (??)
e. vestibular area (???) f. acoustic
tubercle (???) g. medial eminence (????) h.
facial colliculus (????)
14

B. Brain Stem (??)

• i. hypoglossal triangle (??????)
• j. vagal triangle
• (??????)
• k. area postrema
• (???)
• l. inferior medullary velum (???)

15
B. Brain Stem (??)
5) fourth ventricle (????)

• a. tela choroidea of 4th ventricle (????????)
• b. choroid plexus of 4th ventricle (???????)
• c. median aperture of 4th ventricle (???????)
• d. lateral apertures of 4th ventricle (???????)

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B. Brain Stem (??)
3. Internal structure (????)

• 1) nuclei of cranial nerves
• (????)
• ? a. Somatic motor column
• (GSE) (?????)
• i. oculomotor nucleus (III?)
• ii. trochlear nucleus (IV?)
• iii. abducens nucleus (VI?)
• iv. hypoglossal nucleus (XII?)

17
B. Brain Stem (??)
? b. special visceral motor column (SVE) (???????)

• i. motor nucleus of trigeminal nerve (???????) ?
  muscle of mastication
• ii. facial nucleus (????) ? muscles of expression
• iii. nucleus ambiguus (??) ? muscle of pharynx
  and larynx
• iv. accessory nucleus (????) ? trapezius
  sternocleidomastoid

18

B. Brain Stem (??)
? c. general visceral motor column (GVE)
(???????)

• i. accessory oculomotor nucleus
  (Edinger-Westphal) (??????) ? sphincter pupillae,
  ciliary m.
• ii. superior salivatory nucleus (????) ? lacrimal
  gland, submandibular gland, sublingual gland

19
B. Brain Stem (??)

• iii. inferior salivatory nucleus (????) ?
  parotid gland
• iv. dorsal nucleus of vagus nerve (??????) ?
  most viscera in neck, thorax and abdomen

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B. Brain Stem (??)
? d. visceral sensory column (GVS,SVA)
(?????)
nucleus of solitary tract (???) a. gustatory
n.(???) ? taste (VII,IX,X) b.
cardiorespiratory n.(? ???) ? all
sensory of viscera (IX,X)
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B. Brain Stem (??)
? e. general somatic sensory column
(GSA) (???????)

• i. mesencephalic nucleus
• of trigeminal nerve (???????) ? proprioceptive
  sense of masticatory mm.
• ii. pontine nucleus of V. (???????) ? tactile
  sense of head

22

B. Brain Stem (??)
iii. spinal nucleus of trigeminal nerve
(???????) ? pain and thermal sense of head f.
? special somatic sensory column (SSA) (???????)
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B. Brain Stem (??)

• i. ventral dorsal cochlear nuclei (????, ????)
  ? cochlear ganglion (hearing)
• ii. vestibular nuclei (?????) ? vestibular
  ganglion (balance)

24
B. Brain Stem (??)
25
B. Brain Stem (??)

• 2) Noncranial nuclei (?????)
• a. ? gracile nucleus (???)
• Location lower part of medulla.
• ? fasciculus gracilis (T4?)
• ? internal arcuate fibers (?????) ?
  decussation of medial lemniscus (??????) ? medial
  lemniscus (????)
• b. ? cuneate nucleus (???)
• Location upper part of medulla.
• ? fasciculus cuneatus (T4?)
• ? same as gracile nucleus.

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B. Brain Stem (??)
c. inferior olivary nucleus (????) ? all
the central nervous system ?
olivocerebellar fibers ?? inferior
cerebellar peduncle?cerebellum. d. superior
olivary nucleus (????) e. pontine nuclei (???)
? corticonuclear tract ? pontocerebellar
fibers ?? middle cerebellar
peduncle?cerebellum. f. nucleus of inferior
colliculus(???) g. red nucleus (??) h. substantia
nigra (??)
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B. Brain Stem (??)

• 3) white matter (??)
• a. Long sensory tracts (????)
• i. ? medial lemniscus (????)
• ii. ? lateral lemniscus (????)
• iii. ? trigeminal lemniscus (????)
• iv. medial longitudinal fasciculus (????)
  

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B. Brain Stem (??)

• v. anterior spinocerebellar tract
• (??????)
• vi. posterior spinocerebellar tract
• (??????)
• b. Long motor tracts (????)
• i. ? corticospinal tract (?????)
• ii. ? corticonuclear tract (????)
• i ii pyramidal system (????)

Function The voluntary movement of the skeletal
muscles
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B. Brain Stem (??)

• iii. rubrospinal tract (?????)
• iv. tectospinal tract (?????)
• v. olivospinal tract (?????)
• vi. vestibulospinal tract (?????)
• vii. reticulospinal tract (?????)
• iii-vii extrapyramidal system (????)

Functions To regulate the tonicity of the
muscles. To coordinate the
muscular activities. To
maintain the normal body posture and
produce habitual and rhythmic
movements.
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B. Brain Stem (??)

• 4) reticular formation (RF) (????)
• Definition intermingled grey and white matter
  collectively
• Functions
• a. agrypnode (??)
• b. ascending reticular activating system
• (??????)
• c. visceromotor control (??????)
• d. osphresis (??)

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Internal Structure of the Medulla Oblongata

• A. Division (??)
• 1. ? Decussation part (???)
• 1) decussation of medial lemniscus
• (??????)
• 2) decussation of pyramid (????)
• 2. Olivary part (????)
• inferior olivary nucleus (????)
• medial bulbar syndrome ???????
• lateral bulbar syndrome (Wallenberg) ???????

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Internal Structure of the Medulla Oblongata

• ? B. Decussation part (???)

1
??????
decussation of pyramid (????)
cortico- spinal tract 85 (?????)
lat. corticospinal tract
(??????)
muscles of limbs (????)
ant.white commissure
muscles of trunk(???)
ant. corticospinal tract (??????)
2
???????
hypoglossal nuc. nuc. ambiguus accessory
nuc. (??,?,?n?)
cortico- nuclear tract 15 (????)
mm of tongue, pharynx larynx SCM
trapezius (??,???, ????,???)
n.ambiguus??
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Internal Structure of the Medulla Oblongata

• C. ? Olivary part (????)

1
??,????
decus. of med.lemnisc ??????
gracile nuc.
medial lemniscus (????)
internal arcuate fibers (?????)
gracile tr.(??)
cuneate nuc.
cuneate tr.(??)
II
2
lateral spinothalamic tract (??????)
??,???
spinothalamic tract (lemniscus) ?????(????)
anterior spinothalamic tract (??????)
????
34
Internal Structure of the Pons

• A. Basilar Part (???)
• a recent part phylogenetically
• (?????????)
• B. Tegmental Part (???)
• continuation of the medulla
• oblongata (??????)

35
Internal Structure of the Pons

• A. Basilar Part (???)

corticopontine fibers (??????)
pontine nuclei (???)
pontocerebellar fibers (????f)
mid.cerebellar peduncle (????)
sup. olivary nuc. (????)
cochlear nuclei (??????)
lateral lemniscus (????)
B. Tegmental Part (???)
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Internal Structure of the Midbrain

• A. Cerebral Peduncle (???)
• B. Tegmentum (???)
• C.Tectum (???)
• dorsal to the
• mesencephalic
• aqueduct
• (????????)

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Internal Structure of the Midbrain

• A. Cerebral Peduncle (???)
• Descending fibers from the cerebral cortex
  (????????????)
• 1. Pyramidal tract (???) (corticospinal tracts,
  corticonuclear tracts) at the middle 3/5
• 2. Frontopontine tract (???) at medial 1/5
• 3. Parieto-occipito-temporo-pontine tracts
  (?????) at lateral 1/5
• Weber's syndrome ???????

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Internal Structure of the Midbrain

• B. Tegmentum (???)
• 1. Substantia nigra (??)
• 1) reticular part (???)
• 2) compact part (???)
• ? caudate (?) and
• putamen (???)

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Internal Structure of the Midbrain
2. Red nucleus (??)
Red nuc. (??) magnocellular part
(????) parvocellular part (????)
cortex of cerebrum and cerebellum (???????)
?vent. tegmental decus.
rubrospinal tract (?????)
anterior horn (?????)
inf. olivary nuc. (????)
Cerebellum (??)
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Internal Structure of the Midbrain
C. Tectum (???)
1
nucleus of inferior colliculus (???)
lateral lemniscus (????)
med.geniculate body (?????)
brachium of inferior colliculus(???)
2
gray matter layers of sup. colliculus (??????)
brachium of sup. colliculus (???)
tectospinal tract (?????)
dorsal tegmental decussation(?????)
41
Internal Structure of the Midbrain
3
pretectal area (????)
brachium of superior colliculus (???)
accessory oculomotor nuc. (??????)
ciliary ganglion (??n?)
sphincter pupillae and ciliary muscle (?????, ???)
D.
D. Mensencephalic aqueduct (cerebral
aqueduct) (????)
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Ascending Fasciculi of the Pons and Midbrain

• A. Acoustic sense (??)

cochlear nuclei (?n?)
spiral organs (???)
cochlear n (???)
trapezoid body (???)
nucleus of inferior colliculus (???)
brachium of inferior colliculus (???)
LATERAL LEMNISCUS (????)
??? ???? ??? ????
medial geniculate body (?????)
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Ascending Fasciculi of the Pons and Midbrain

• B. ? Sensory of face (pain and temperature)
  (?????)

(?????)
spinal tract of V. n. (??????)
spinal nucleus of V.n. (???????)
Thalamus (ventroposterior medial nuc.) (???????)
Trigeminal Lemniscus (????)
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Ascending Fasciculi of the Pons and Midbrain
C. Tactile sense of face (????)
tactile sense of face (????)
trigeminal n. (????)
pontine nucleus of V.n. (???????)
THALAMUS (ventroposterior medial nuc.) (???????)
trigeminal lemniscus (????)
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Ascending Fasciculi of the Pons and Midbrain

• D. Equilibratory sense of head (?????)

nuclei of ?,?,? (III,IV,VI?)
extraocular mm. (???)
III,IV,VI nerves
equilibratory sense of head (?????)
vestibular n. (?????)
vestibular n. (????)
medial longitudinal fasciculus (????)
nuclei of XII, ant. horn) (?,????)
mm. of tongue limbs (?,????)
related nn. (????)
46
Descending Fasciculi of the Pons and Midbrain

• ? Voluntary movement (????)

pyramidal tract (in middle 3/5 crus
cerebri) (???)
corticospinal tract (?????)
corticonuclear tract (????)
all cranial nuclei (????)
facial nuc. (lower 2/3) (?n?)
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Reticular Formation of the Brain Stem

• Definition The field intermingled cell bodies of
  neuron (grey) and nerve fibers(white matter)
  collectively termed reticular
  formation (RF)
  (?????????????????)
• Characteristics Wide spread network, almost all
  the afferent and efferent fibers connect all the
  central nervous system
• (????,???????????????).

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Reticular Formation of the Brain Stem

• Functions
• A. Somatomotor control (??????)
• B. Activation of the behavioral arousal,
  maintain the conscious state of cerebral cortex.
  (??????)
• ? ascending reticular activating system
  (????????) senses ? RF ? cerebral cortex deep
  coma ???

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Reticular Formation of the Brain Stem

• C. Visceromotor control (??????) a series of
  vital functional centers
  (respiration, cardiovascular
  controlling, vomiting, etc.)
• cerebral cerebellar cortex ? RF ?
  reticulospinal tract ? anterior horn.
• D. Osphresis(??) limbic system(????) ? RF
  (rapheal nuclei???)

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Reticular Formation of the Brain Stem

• E. Main nuclei (????)
• 1. Rapheal nuclei (???) in median plane of
  brain stem(???????).
• 2. central (medial) group (???) in paramedian
  plane of brain stem (?????????).
• 3. Cerebellar reticular formation nuclei
  (????????)
• 4. Nuclei of catecholamine (CA) (??????) locus
  ceruleus (??).

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Reticular Formation of the Brain Stem

• E. Main nuclei (????)1. Rapheal nuclei (???)
  in median plane of brain stem(???????).
• Transmitter (??)
• 1) 5-HT (5-hydroxytryptamine) (????)
• 2) enkephalin (???)
• 2. central (medial) group (???) in
  paramedian plane of brain stem (?????????)
  Transmitters enkephalin (???)

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Reticular Formation of the Brain Stem

• 3. Cerebellar reticular formation nuclei
  (????????) 1) lateral R N (?????) 2)
  paramedian R N (??????) 3) tegmentoreticular
  nucleus of pons (???????)
• 4. Nuclei of catecholamine (CA) (??????) locus
  ceruleus (??)