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(spinal cord)

, vertebral column spinal canal (vertebral canal)

, meninges, CSF

: foramen magnum : ; L1

; L3

Spinal enlargements 1. Cervical enlargement: C3-T2, brachial plexus

2. Lumbar enlargement: L1-S3, lumbosacral plexus

(conus medullaris) (filum terminale)

cylinderical structure(: 43-45 cm, : 1-1.5 cm)

: 45cm : 42cm : 1cm

Spinal enlargements1. Cervical enlargement: C3-T2

2. Lumbar enlargement: L1-S3

(cauda equina)

cervical nerves ---------8 thoracic nerves------ 12 lumbar nerves ------- 5 sacral nerves -------- 5 coccygeal nerves ----- 1

31

: , . L5 : HIVD

5-3

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Sulcus and fissure

anterior median fissure

anterolateral sulcus (ant. Roots)

posterior median sulcus

posterolateral sulcus(post. Roots)

posterior intermediate sulcus

Ant & post root spinal nerve ant primary division (APD) &

post primary division (PPD)

5-1

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5-2

1. White matter

(1) anterior funiculus = ant. white column

(2) posterior funiculus = post. white column

1. gracile fasiculus ():

2. cuneate fasicleus (): gracile fascilus

(3) lateral funiculus = lat. white column

(4) white commisure

(5) dorsolateral tract (tract of Lissauer)

2. Gray matter

(1) Anterior horn : motor cell (A, A)

(2) Posterior horn

(3) Lateral horn : T1-L2 & S2-4 ; preganglionic sym-/parasympathetic neuron

(4) Gray Commissure

(5) intermediate zone

3. Central canal

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Barr fig.5-4,5,6 * 1) (>)

2) (1)

(2)

3) (1)

(2)

(3)

4) Thoracic lumbar segmentlateral horn

Cytoarchitectural lamination

Laminae of Rexed ()

Dorsal horn : I, II, III, IV, V, VIIntermediate zone : VII, XVentral horn : VIII, IX

Nucleus of Onuf: , pelvic floor sphincter

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Dorsal horn

1. Lateral division

(1) Unmyelinated C or A delta fibers

(2) Substantia gelatinosa (Lamina II) ( dorsolateral tract (of Lissauer) ( 2-3)

(3) Lamina I, IV, V, VI axon spinothalamic tract()

2. Medial division

(1) Myelinated A fibers dorsal funiculus F. gracilis and cuneatus (Discriminative sense, Proprioception )

(2) lamina IX motor neuron stretch reflex

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5-8

Barr fig.5-10

5-9

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1. Visceral motor nuclei (in thoracolumbar region)(1) Lamina VII Intermediolateral nuclei

(2) Sympathetic preganglionic fibers

(3) Anterior root - Spinal nerve - White communicating ramus

sympathetic ganglion-Postganglionic fibers

(4) Postganglionic fibers

a. unmyelinated fiber gray communicating ramus

b. -, , arrector pili muscle

2. Visceral motor nuclei (in Sacral region)(1) Lamina VII Intermediolateral nuclei

(2) Parasympathetic preganglionic fibers

(3) postganglionic fiber

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(, )

5-10

(General Sensory system, Ch 19)

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1. 1)

1st-order neuron 2nd-order neuron 3rd-order neuron cerebrum

(Soma in sp. ganglion) (Soma in sp. cord) (Soma in brain)

2) (Branches)(1) To motor neurons : (2) To reticular formation

2. ()1) (Conscious sensory information)

(1) () (2) Spinothalamic tracts, Fasciculus gracilis and cutaneous (dorsal column-medial

lemniscus system)

2) (Unconscious sensory information)(1) ()(2) Spinocerebellar tracts and Cuneocerebellar tract, Spino-olivary tract

3) (Other sensory information)(1) Spinotectal tract: (spinavisual reflex) (2) Spinoreticular tract: (ascending reticular

acivating system)

19-1

, ,, Spinothalamic system

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1. (anatomical organization)

1)

1st-order neuron (Upper motor neuron) 2nd-order neuron (Inter neuron)

(in brain) (in spinal cord or brain stem)

3rd-order neuron (Lower motor neuron)

(in spinal cord)

2) (branches)

(1) To cortex : inhibit activity in adjacent regions of the cortex

(2) To subcortical regions (basal ganglia, red nucleus, olivary nuclei, reticular

formation) :

2. ()

1) (corticospinal tracts) : (voluntary,

rapid, discrete, skilled movements)

2) (extrapyramidal, subcortical descending tracts):

(simple basic voluntary movements)

3) (descending autonomic tract) :

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(motor system)

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1. Medulla oblongata

1.

: : :stria medullaris

: ponto-medullary (inf. potine) sulcus

: rootlets of first cervical spinal n.

2. Anterior surface

(1) Pyramid

(2) Olive

(3) Preolivary sulcus : rootlets of XII

Postolivary(posterolateral) sulcus : rootlets of cranial nerve IX, X, XI

(4) Pontomedullary junction: roots of cranial nerve VI, VII, VIII

3. Posterior surface

(1) Gracil tubercle() & cuneate tubercle()

(2) 4( 1/2) :

(3) Inferior cerebellar peduncle()

6-1

2. Pons

1. bridge

:

: superior pontine sulcus

: trochlear nerve

2.

(1) Basilar sulcus: basilar groove for basilar artery

(2) Trigeminal nerve roots : medial motor & lateral sensory

3.

(1) 4( 1/2) :

median sulcus (),

medial eminence (),

facial colliculus (),

sulcus limitance (),

(2) 4 : Inf. & sup. cerebellar peduncles

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3. Midbrain

1. : mammilary bodies()

2.

(1) Cerebral peduncle (),

interpeduncular fossa (),

posterior perforated substance

()

(2) Oculomotor nerve()

3.

(1) Superior colliculi and superior

brachium (LGB)

(2) Inferior colliculi and inferior brachium

(MGB)

(3) Trochlear nerve

1.

1. Level of pyramidal decussation

1) Pyramidal decussation

ant. corticospinal tract

lat. corticospinal tract

2) F & N gracilis

F & N cuneatus

3) Spinal tract and nucleus of trigeminal n.

(1) Extend caudally as far as C2

(2) Function : sense of pain, temp. of face

2. Level of decussation of medial lemniscus

1) Internal arcuate fibers (from N. gracilis and

cuneatus) & decussation of medial

lemniscus

2) Nucleus of spinal tract (CN V)

3) Spinal lemniscus : spinothalamic tracts &

spinotectal tract

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Ascending Pathway ()1. Dorsal column - Medial lemniscus system (DC-ML)

1. Discriminative touch () & proprioception ()

2. Post root (spinal cord)

Gracile fasciculus ( & ) & cuneate fasciculus (, , )

N. of gracile & cuneate

internal arcuate fiber

decussation

medial lemniscus

lateral division of VPI of

thalamus

corona radiata

primary sensory area

* DC-ML system .

2. Spinothalamic tract (anterolateral system)

spinal lemniscus

1. lateral spinothalamic tract

1)

(lamina I, IV, V, VI) axon ( 1)

2) : (pain, temperature)

3)

Post root

Posterolateral tract of Lissauer

Gray Column (Lamina I, IV, V, VI)

--x

Lat. Spinothalamic tr.

Spinal lemniscus

VPL of Thalamus

int. cap (post limb)

Corona radiata Primary sensory area (cerebral cortex)

2. Anterior spinothamic tract

1) : (anterior nerve root )

2) : (light touch, pressure)

3) : Lat. spinothalamic tract

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1. corticospinal tract

1. ( 1)1) (lateral corticospinal tract) : lat. funiculus 2) (ant. corticospinal tract) : 3) (lamina IV,VIII IX)

2. : (voluntary, discrete, skilled movements)

3. Pyramidal cells Corona radiata Cerebral peduncle

(cerebral cortex) (midbrain)

Pyramidal decussation -- Ant. CS tr. (15%) Spinal grey matter

--x--- Lat. CS tr. (85%) Spinal grey matter

4. (branch) : cerebellar cortex, caudate nucleus,lentiform nucleus,red nucleus, olivary nucleus, reticular formation

5. Homunculus () :

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Descending Spinal Tracts

lateral pathway vs. ventromedial pathway

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Descending Spinal Tracts

The Lateral Pathways

Voluntary movement under direct cortical

control

Components

Corticospinal tract (=Pyramidal tract)

Rubrospinal tract:

Input: frontal cortex

Output: primarily upper limb frontal cortex corticospinal tract

. indirect cortico-rubro-spinal tract? rubrospinal tract corticospinal tract .

The Ventromedial Pathways

Posture and locomotion under brain stem control

The Vestibulospinal tract

(VOR)

extensor

The Tectospinal tract

2

The Pontine and Medullary Recticulospinal tract Pontine reticuospinal tract: anti-gravity

Facilitating extensor m

Medullary reticulospinal tract:

Liberates the anti-gravity muscle from reflex control

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1.

1. Level of pyramidal decussation

1) Pyramidal decussation

ant. corticospinal tract 1/3

lat. corticospinal tract 2/3

2) F & N gracilis

F & N cuneatus

3) Spinal tract and nucleus of trigeminal n.

(1) Extend caudally as far as C2

(2) Function : sense of face

2. Level of decussation of medial lemniscus

1) Internal arcuate fibers (from N. gracilis and

cuneatus) & decussation of medial

lemniscus

2) Nucleus of spinal tract (CN V)

3) Spinal lemniscus : spinothalamic tracts &

spinotectal tract

3. Level of the olives

1) Olivary nuclear complex

(1) Inferior olivary nucleus

(2) Accessory olivary nuclei : medial and dorsal

2) Vestibular nuclei

(1) Inf., lat., med. vest n. (in med oblong)

Sup. vest n. (in pons)

3) Cochlear nuclei

(1) Ant. cochlear n.

(2) Post. cochlear n.

4) Nucleus ambiguus ()(1) Motor nuclei for cranial n. IX, X, XI

5) Central gray matter

(1) Hypoglossal nucleus

(2) Dorsal nucleus of vagus

(3) Inferior salivatory nucleus

(4) Nucleus of tractus solitarius

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Vestibulocochlear nerve (VIII)

1. vestibular nuclei

(1) Inf., lat., med. vest n. (in med oblong)

Sup. vest n. (in pons)

(2) Concious balance of body (via cerebellar and cerebral connection)

(3) Maintain head and eye movement for visual fixation on the object

(4) ( 11-13)

Vestibular n.

Vest nuc.

1. Inf. cerebellar peduncle Cb

2. Cerebral cortex (vestibular area)

3. Spinal cord (vestibulospinal tr.)

4. Median longitudinal fasciculus (MLF) Cranial n. III,VI, IV

2. Cochlear nuclei

(1) Ant. cochlear n.

(2) Post. cochlear n.

(3) ( 11-14)

Spiral gang.

Cochl n.

Cochl nucleus

Trapezoid body & sup. olivary nucleus

Lateral lemniscus

Inf. colliculus

Inf. brachium

Medial geniculate body (MGB)

Auditory area (sup. temp gyrus) (Wernickes area)

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2. (pons)

1. Transverse section through caudal part of pons

1) Medial lemniscus : most anterior part of

tegmentum

2) Spinal lemniscus

3)

4) MLF

(1)

5) Facial nucleus

6) Abducent nucleus

7) Post & ant cochlear nuclei

8) Spinal nucleus of trigeminal nerve

9) Pontine nucleus ()

(1)

Facial & Abducens nerve

1. Facial motor nucleus

1) motor n.

2) Facial nucleus internal genu

facial colliculus abducens

nucleus

2. Abducens nucleus

1) lateral rectus m.

2) facial colliculus

3) internuclear neuron

. Internuclear neuron

MLF medial rectus m.

division

of oculomotor nucleus

conjugate

lateral eye movement ()

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PPRF

: paramedian pontine reticular formation

: center for lateral gaze

1. Longitudinal fiber bundle ()

1) corticospinal fiber

2) corticopontine fiber

2. Transverse fiber bundle ()

1) pontocerebellar fiber

3. Pontine nuclei

*

1)

2)

corticopontine tract pontine

nuclei pontocerebellar tract

via middle cerebellar peduncle

dentate nucleus via sup. cerebellar

penducle red nucleus & VL of thalamus

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3. (midbrain)

Tectum ()

Cerebral peduncle ()

Tegmentum ()

Substantia nigra ()

Basis peduncli ()

= Crus cerebri ()

1. Tectum and asociated tracts

1) Inferior colliculus

2) Superior colliculus

2. Tegmentum

1) Nucleus of trochlear n. superior

oblique of eye ball

2) Nuclei of oculomotor n. ()

3) Lemnisci : Medial, spinal, trigeminal, lateral

4) Medial longitudidnal fasciculus

5) Mesencephal nuc of trigeminal n.

6) Decussation of superior cerebellar peduncles

7) Substantia nigra

8) Red nucleus

; vascularity and iron-containing pigment

3.

1) corticospinal tract & corticonuclear tract

2) corticopontine tract

1) Frontopontine fiber (medial)

2) Temporopontine fiber (lateral)

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(substantia nigra)

1. Copus striatum

2. Pars compacta

1) dopaminergic neuron

2) melanin pigment

3. Pars reticulata

4. Parkinsons disease

1) ; muscular rigidity (), tremor (),

bradykinesia (), mask-like face (),

shuffling gait

2) Degeneration of dopaminergic neuron

3) MPTP

4) Dopamine dopamine BBB L-dopa . L-dopa . L-dopa , .

5) Therapeutic graft

Trigeminal nerve

Trigeminal sensory nucleus

Skin of face and forehead, scalp, mucosa of the oral and nasal

cavities, paranasal sinuses, and teeth trigeminal ganglion

Main sensory nucleus ( = pontine trigeminal, chief, superior sensory nucleus )

Spinal nucleus (): pons~C2,3

Ventral trigeminothalamic tract: . Spinothalamic tract medial division of ventral posterior of thalamus. Spinothalamic tract V5T.

trigeminal lemniscus

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Mesencephalic nucleus ()

Primary sensory neuron CNS

Mesencephalic tract of trigeminal nerve

Trigeminal motor nucleus

Trigeminal ganglion (masster, temporalis, lat., med. pterygoid m.), tensor typamni, tensor veli palatini,

ant. belly of digatstric, mylohyoid m.

Jaw jerk:

Jaw-opening reflex: .