NS, Meninges, And Ventricles

7/26/2019 NS, Meninges, And Ventricles

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Maj-MajDeriada,M.D.

Development ofthe NervousSystem

Meninges

Ventricles


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Competencies: Development of theCNS

> Describe the formation of the neural tube

> Describe the subsequent formation of theprimary and secondary brain vesicles

> Name the corresponding ventricles in eachof the brain vesicles

> Enumerate the adult derivatives of each of

the secondary brain vesicles> Enumerate the cells in nervous tissue anddescribe briefly their origin anddevelopment


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> Describe the origin of neural crest cells> State the adult derivatives of the different

layers of the neural tube

1 Ventricular !one "ependymal layer#

$ Mantle layer

% Marginal layer

> &ive the functional significance of the alar

and basal laminae> State the more common congenital

anomalies that occur during the

development of the 'NS


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Competencies: The Meninges ofthe Brain and Spinal Cord

> Name(describe the three meninges> Define the terms )pachymenin*+ and)leptomenin*+

>Describe the dural reflections and theformation of the,

1 fal* cerebri

$ fal* cerebelli

% tentorium cerebelli

- diaphragma sellae

> .dentify the dural venous sinuses


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> Name the spaces associated /ith themeninges and the contents of each

> Describe the )anatomical+ basis of the blood0brain barrier "#

> Describe the mechanism of epidural andsubdural hematoma

> Describe the formation of the 2acchionian

"arachnoid# granulations and their role in theabsorption of 'S3

> Define and locate the cisterns

> State the lo/est possible level of termination

of the spinal cord


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Competencies:The VentriclarS!stem

> Describe the ventricular system of the brain> 4ocate the sites of formation and absorption

of cerebrospinal fluid

> Enumerate the areas /here 'S3 is normallyfound

> 5race the flo/ of 'S3 from the area offormation to the area of absorption

> State the usual site /here 'S3 is obtained> State the composition and functions of 'S3

> Differentiate the mechanism of formation ofthe communicating and noncommunicating

types of hydrocephalus


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Early

Development


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Development of the Nervous System:Development of the Nervous System:

% Main 'ell 4ayers,% Main 'ell 4ayers,

EntodermEntoderm 0 &.50 &.5

0 lungs0 lungs

0 liver0 liver

MesodermMesoderm 0 muscle0 muscle

0 connective tissue0 connective tissue0 vascular sys0 vascular sys

"ctoderm - nervos s!s.


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Development of theDevelopment of the

Nervous System:Nervous System:

%%rdrd/ee6,/ee6,

EctodermEctoderm

neural plateneural plate

neural grooveneural groove

neural foldsneural folds

neural tubeneural tube

3use at the midpoint


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Neral t#e:

> 7nterior andposteriorneuropores

> closure is

complete /(in -/6s

> sin6s beneath

surface ofectoderm


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Neural crest,


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Primary Brain Vesicles:Primary Brain Vesicles:


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SpinalCord


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Development of the Spinal Cord:Development of the Spinal Cord:

8Ependymal cells0fr matri* cells9 line the neural tube

$NT"%M"D$&T"'M&NT(" ).

*+%& M&TT"%

Matricells

Matri* cells0pseudostratified

columnar epithcells

V"NT%$C/(&% )0N"

M&%+$N&( ).-m!elinated*12$T"M&TT"%

0 7stro0(oligodendrocytes


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Developing spinal cordDeveloping spinal cord

3loor :;oof

2lates


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.ntermediate!one,

asal plate

0 motor cells

7lar plate0 sensory

cells

Sulcuslimitans


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7ntMedian

fissure

2osterior

medianseptum

'entral

canal


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Development of the Meninges9;elation of

the Spinal 'ord to theVertebral 'olumn,

2ia< arachnoid : dura mater0 sclerotome

Subarachnoid space0 'S3

1st$ mos = same lengthvert column gro/s more

rapidly

at birth 0 end of cord at 4%

adult 0 lo/er border of 41


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> Disproportion in rate of gro/th ant and post roots belo/ 41

> 2ia mater filum terminale

'auda equina "S$#0 S7 space Spinal tap 'ervical(4umbar

enlargements "-thmo#


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Brain


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DivisionsDivisions

of theof theDevelopingDeveloping

Brain:Brain:

prosencephalonprosencephalon

mesencephalonmesencephalon

rhombencephalonrhombencephalon

th/ee6


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The Primary Divisions of the Developing Brain:The Primary Divisions of the Developing Brain:

1? Division, $? Division, 7dult Structures,1? Division, $? Division, 7dult Structures,

prosencephalon telencephalonprosencephalon telencephalon cere#ral hemispherecere#ral hemisphere

"forebrain#"forebrain# basal gangliabasal ganglia hippocampushippocampus

diencephalondiencephalon thala0(hypothalamusthala0(hypothalamus

pineal bodypineal body infundibuluminfundibulum

mesencephalonmesencephalon tectumtectum

"midbrain#"midbrain# tegmentumtegmentum

crus cerebricrus cerebri

rhombencephalon metencephalonrhombencephalon metencephalon pons, cere#ellmpons, cere#ellm

"hindbrain#"hindbrain#

myelencephalonmyelencephalon medlla o#longatamedlla o#longata


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VentricularVentricular

System:System:

th/ee6

Ependyma

'S3

$NT"%V"NT%$C/(&%30%&M"N *30%&M$N& 03

M0N%0

"iter#


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Medulla !longata "Myelencephalon#:Medulla !longata "Myelencephalon#:

asal plates0 'N .@ to @..

7lar plates 0 'N V< V...< .@ and @

0 gracile : cuneate nuclei

0 olivary nuclei


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5ela choroidea choroid

ple*us

-th0thmos,

3oramen of 4usch6a

3oramen of Magendie

0 'S3


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4!ramid

2recentral gyrus descendinga*ons pyramid


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Pons: Metencephalon$ VentralPons: Metencephalon$ Ventral

asal plates0 'N V< V. and V..

7lar plates0 'N V< V.. and V...9 pontine nuclei

C ! llC ! ll


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Cere!ellum:Cere!ellum:

Metencephalon$ posteriorMetencephalon$ posterior;hombic lip

1$th/6


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'erebellum,

Superiorvie/

.nferiorvie/

-thmo0 fissures


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Cere!ellum:Cere!ellum:

'erebellar corte*

Dentate< other deep nuclei

'erebellar peduncles,

Superior

Middle

.nferior


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Mid!rain: MesencephalonMid!rain: Mesencephalon

asal plate,

'N ...< .V

;ed nucleiSubstantia nigra

;eticular

formation

C0%T$C040NT$N" T.

C0%T$C0B/(B&% T.

C0%T$C0S4$N&( T.CN $$$


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Mid!rain:Mid!rain:

Superior colliculi0 visual refle*es

.nferior colliculi0 auditory refle*es


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%ore!rain%ore!rain"Prosencephalon#:"Prosencephalon#:

04T$CV"S$C("

;E5.N7 7NDA25.' NE;VE


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%ate of the Telencephalon:%ate of the Telencephalon:


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%ate of the Telencephalon:%ate of the Telencephalon:

...


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Cerebral Hemispheres:

th/ee6

3&(5

C"%"B%$


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Cerebral

Hemispheres:'horoid ple*us0function

Corpsstriatm


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2$440C&M4/S

.N5E;N74 '72SB4E0asc(desc tracts


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CerebralCerebral

Cortex:Cortex:convolutions(gyri

sulci(fissures

insula

4entiformnucleus


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%ate of the Diencephalon:%ate of the Diencephalon:

0 pineal body

...


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M&MM$((&% B0D$"S

T2&(&M/S

$NT"%T2&(&M$C

C0NN"CT$0N

240T2&(&M$CN/C("$

...


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$N3/ND$B/(/M


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Clinical Correlates: Common Defects of the CNS

Spina bifidaSpina bifida

0 spines and arches0 spines and arches0 lo/er thoracic< lumbar and sacral regions0 lo/er thoracic< lumbar and sacral regions

0 meninges and spinal cord0 meninges and spinal cord

0 failure of mesenchyme to0 failure of mesenchyme to

form the vertebral archesform the vertebral arches

CydrocephalusCydrocephalus

7nencephaly7nencephaly


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Clinical Correlates: Common Defects of the CNS

Spina bifida, 5ypesSpina bifida, 5ypes

6. Spina Bifida 0cclta

2ostvertebral muscles

5uft of hair< fatty tumor

Symptomless9 no treatment

@0ray


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7. Meningocoele

'S3

Subarachnoid space

Spinal cord< nerves usunormal

Surgery


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8. M!elomeningocoele

Spinal cord and nerve roots

are adherent to the sac

Surgery


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Cydrocephalus


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Hydrocephalus:Hydrocephalus:

Noncommunicating Cydrocephalus loc6age bet/een choroid ple*uses and the apertures of

the -thventricle

'ommunicating Cydrocephalus No obstruction 'S3 reaches the subarachnoid space .rritation of meninges9 inc 'S3 viscosity

0aqueduct stenosis0aqueduct stenosis0masses0masses0haematoma< intraventricular0haematoma< intraventricular

0tumors0tumors0abscesses0abscesses0atresia of apertures0atresia of apertures


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7nencephaly,

rain and vault

rostral end of neural tube

Aptic n0 absent

open neural tube

BS&( *0ray

still born< die shortly


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Summary/Review:

9

99

9

9

9


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The Primary Divisions of the Developing Brain:The Primary Divisions of the Developing Brain:

1? Division, $? Division, 7dult Structures,1? Division, $? Division, 7dult Structures,

prosencephalon telencephalonprosencephalon telencephalon cere#ral hemispherecere#ral hemisphere

"forebrain#"forebrain# basal gangliabasal ganglia hippocampushippocampus

diencephalondiencephalon thala0(hypothalamusthala0(hypothalamus

pineal bodypineal body infundibuluminfundibulum

mesencephalonmesencephalon tectumtectum

"midbrain#"midbrain# tegmentumtegmentum

crus cerebricrus cerebri

rhombencephalon metencephalonrhombencephalon metencephalon pons, cere#ellmpons, cere#ellm

"hindbrain#"hindbrain#

myelencephalonmyelencephalon medlla o#longatamedlla o#longata


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Developing Spinal CordDeveloping Spinal Cord


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> Describe the formation of the neural tube> Describe the subsequent formation of the

primary and secondary brain vesicles

> Name the corresponding ventricles in eachof the brain vesicles

> Enumerate the adult derivatives of each ofthe secondary brain vesicles

> Enumerate the cells in nervous tissue anddescribe briefly their origin anddevelopment

Competencies: Development of the


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> Describe the origin of neural crest cells

> State the adult derivatives of the differentlayers of the neural tube

1 Ventricular !one "ependymal layer#

$ Mantle layer

% Marginal layer

> &ive the functional significance of the alar

and basal laminae> State the more common congenital

anomalies that occur during thedevelopment of the 'NS


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Meninges o the !rainMeninges o the !rainand Spinal Cord:and Spinal Cord:

7rachnoid mater

2ia mater

Dura mater0 pachymenin*

leptomeninges

Meninges of the Brain:Meninges of the Brain:


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Dra Mater: 7 la!ersDra Mater: 7 la!ers

0 Venos sinsesVenos sinses

0

"ndosteal la!er-"ndosteal la!er- notcontinos ' dra m. of thecontinos ' dra m. of thespinal cordspinal cord

- continos ' the periostem- continos ' the periostem

0 Meningeal la!er- dense, strong mem#raneMeningeal la!er- dense, strong mem#rane

- continos ' the dra m. of the spinal cord- continos ' the dra m. of the spinal cord


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foramina

M i f th B iM i f th B i


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Dura Mater,Dura Mater,"

- septa, restrict displacement- septa, restrict displacementof brainof brain

3al* cerebri3al* cerebri

0 bet cerebral hem0 bet cerebral hem0tentorium cerebelli0tentorium cerebelli

0sup : inf sagittal0sup : inf sagittal

sinusessinuses

0straight sinus0straight sinus5entorium cerebelli

0tentorial notch "midbrain#

0 transverse sinus



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gg

3al* cerebelli0 bet cerebellar hem

0 occipital sinusDiaphragma sellae

0 sella turcica

0 hypophysis cerebri

Dura Mater:Dura Mater:


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Nerve Supply 0 branches of 'N V< @ : 1st% cervicalspinal nerves

0 sensory endings "stretch#7rterial Supply 0internal carotid aa

0ma*illary a middle meningeal a0asc pharyngeal a

0occipitalaa

0vertebral aaMiddle meningeal a

0 foramen spinosum0 bet dural layers

0 temporal to parietal bone0 anterior br pterion0 precentral gyrus0 veins pterygoid venous

ple*us or sphenoparietal

sinus

Dura MaterDura Mater


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Venous Sinuses = bet the dural layers

0 endothelium9 no valves

0 main function

blood int Fugular vv

'S3

0 emissary vv

Dural Venous Sinuses:Dural Venous Sinuses:


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1# sup sagittal sinus1# sup sagittal sinus confluence of the sinusesconfluence of the sinuses occipitaloccipitalsinussinus

";# transverse sinus";# transverse sinuscommunicates /ith venous lacunaecommunicates /ith venous lacunae

arachnoid villi9 diploic and meningeal vv arachnoid villi9 diploic and meningeal vvsuperior cerebral vvsuperior cerebral vv Superior vie/



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$# inf sag sinus$# inf sag sinus G great cerebral v straightG great cerebral v straight sinussinus%# straight sinus%# straight sinus 4 transverse sinus4 transverse sinus

Superior vie/



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-# 4 : ; transverse sinus= begin, internal occipital protuberance

0 fi*ed margin of tentorium cerebelli 0 receive, superior petrosal sinuses , inf cerebral(cerebellar vv

, diploic vv0 ends, sigmoid sinus

Superior vie/



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# sigmoid sinus Fugular foramen int Fugular vein

H# occipital sinus = begins, foramen magnum9 attached margin offal* cerebelli

0 vertebral veins9 confluence of sinuses



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I# 'avernous sinus0 middle cranial fossa9 spongy appearance

0 internal carotid a and nerves9 'NJs %0H

0 tributaries, sup(inf ophthalmic vv

, sphenoparietal s , inf cerebral vv

, central vein of the retina Superior vie/

'oronal section



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'avernous sinus

0 drains to, sup(inf petrosal sinuses transverse sinus and .KV

,pterygoid venous ple*us

0 intercavernous sinusesSuperior vie/



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'avernous sinus0 route of infection

Arachnoid Mater


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Arachnoid Mater

Delicate and impermeableDelicate and impermeable et/een dura and piaet/een dura and pia

matermater Subdural spaceSubdural spaceSubarachnoud spaceSubarachnoud space

et arachnoid and piaet arachnoid and piamater, delicate strands ofmater, delicate strands offibrous tissuefibrous tissue

ridge over the sulciridge over the sulci Subarachnoid cisternaeSubarachnoid cisternae

C"%"B"((0M"D/((&%C$ST"%N

$NT"%4"D/NC/(&%C$ST"%N

40NT$N"C$ST"%N

Arachnoid Mater


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Arachnoid Mater

arachnoid villi(granulationsarachnoid villi(granulations

"2acchionian gran#"2acchionian gran#

0 superior sagittal sinus0 superior sagittal sinus0 function0 function

S7 space0 'erebral aa and vv9S7 space0 'erebral aa and vv9

0 'N0 'N

fuses /( epineuriumfuses /( epineurium

Arachnoid Mater


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Arachnoid Mater

Aptic Nerve

3uses /( thesclera

Pi M t


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Pia Mater

.t is a vascular membrane

.nvests gyri and sulci 3uses /( epineurium of 'N 'erebral aa0 /ith sheath of pia mater 5ela choroidea

choroid ple*us


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Meninges of the Spinal CordMeninges of the Spinal Cord

3 layers:

Dura mater:

Foramen magnum S2, lower border

extradural space:

loose areolar tissue

internal !ertebral !enous plexus

Spinal ner!e root epineurium


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3 layers:

"rachnoid mater

# S" space with CSF

# Foramen magnum S2, lower border

# Spinal ner!e root S" space


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2ia Mater,>4igamentum

denticulatum

0 function

> Nerve roots

Denticulate ligament


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Clinical Correlation:Clinical Correlation:

Epidural hematoma

0Meningeal aa and vv

middle meningeal a Name(describe the three meninges> Define the terms )pachymenin*+ and)leptomenin*+

>Describe the dural reflections and theformation of the,

1 fal* cerebri

$ fal* cerebelli

% tentorium cerebelli

- diaphragma sellae

> .dentify the dural venous sinuses

Competencies: The Meninges of


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> Name the spaces associated /ith themeninges and the contents of each

> Describe the anatomical basis of the blood-brain barrier (BBB)

> Describe the mechanism of epidural andsubdural hematoma

> Describe the formation of the Pacchionian(arachnoid) granulations and their role in the

absorption of CSF

> Define and locate the cisterns

> State the lo/est possible level of termination

of the spinal cord


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#entricular#entricular

System:System:

#entricular System:#entricular System:


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#entricular System:#entricular System:

4ateral ventricles terminal ventricle "central canal#

Ependyma< 'S3

&ateral Ventricles:&ateral Ventricles:


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&ateral Ventricles:&ateral Ventricles:

$ cavities, 'erebral hemispheres '0shaped - parts ody = corpus callosum 0 caudate nucleus :

thalamus

0 septum pellucidum

'horoid ple*us0

choroidal fissure

''rdrd ventricle:ventricle:


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' ventricle: %rdventricle0 bet $ thalami 'horoid ple*us0 tela choroidea

lood supply of choroid ple*us "lateral : %rdventricles#0choroidal br of int carotid : basilar aa

Venous drainage,

int cerebral vvgreat cerebral vstraight sinus

Cere!ral a(ueduct of Sylvius ) *Cere!ral a(ueduct of Sylvius ) *ththventricleventricle


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( y( y

'erebral aqueduct0 L in long -thventricle

0 pons : upper medulla0 cerebellum0 apertures "foramen#

0 choroid ple*us "bld supply#,post inferior cerebellar aa

importance

Cerebrospinal $luid:Cerebrospinal $luid:


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pp

here is it found

2hysical 'haracteristics,7ppearance clear< colorless

Vol 1% ml

;ate of production ml(min

2ressure "lateral H01 mmC$

recumbent#'omposition,

2rotein 10- mg(1ml

&lucose 0O mg(1ml

'hloride I$0I mg(1ml

No of cells 0% lymphocytes(cu mm

May increase



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3unctions,3unctions,

1# 2rovides mechanical buoyancy : support for the1# 2rovides mechanical buoyancy : support for thebrainbrain 'ushions : protects the 'NS from'ushions : protects the 'NS from

traumatrauma$# Serves as a reservoir and assists in the$# Serves as a reservoir and assists in the

regulation of the contents of the s6ullregulation of the contents of the s6ull%# Nourishes the 'NS%# Nourishes the 'NS-# ;emoves metabolites from the 'NS-# ;emoves metabolites from the 'NS# Serves as a path/ay for pineal secretions to# Serves as a path/ay for pineal secretions to

reach the pituitary glandreach the pituitary gland



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pp

3ormation,3ormation,

1# choroid ple*uses0 lateral< %1# choroid ple*uses0 lateral< %rdrdand -and -ththventriclesventricles

$# ependymal cells of ventricles$# ependymal cells of ventricles%# brain substance%# brain substance

C20%0$D 4("5/S *fold:

P'a

Mg

C'A%

glucose

7ctive5ransport

'S3

Circulation of the CS%:Circulation of the CS%:


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Circulation of the CS%:Circulation of the CS%:

choroid ple*uschoroid ple*us

'S3'S3lateral ventlateral vent

%%rdrdventvent

--ththventvent venous sinusesvenous sinuses

aperturesapertures

arachnoid villiarachnoid villi

subarachnoid spacesubarachnoid space

cerebral hemispherescerebral hemispheres

subarachnoid cisternssubarachnoid cisterns

spinal cordspinal cord

.ntervent 3or

'erebral 7q

7id in circulation,

7rterial pulsations "choroid ple*us venous sinus absorption

Venous sinus pressure > 'S3 compression of villi tips

0 prevent reflu* of blood intosubarachnoid space

0 villi )valves+

Blood+BrainBlood+Brain "+Spinal Cord#"+Spinal Cord#Barrier "BBB#:Barrier "BBB#:


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Q0 gases< /ater

@ = glucose< electrolytes

0 plasma proteins(

large organic molecules

5- pineal gland

post. pititar!

t#er cinerem

all of optic recess

floor of ;thventricle,

postrema

permea#ilit! - inversel!

related to mol. si


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Not identical in all regions


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$unctional Signiicance o the !!!:$unctional Signiicance o the !!!:

Semipermeable barrier 2;A5E'5 the brain andSemipermeable barrier 2;A5E'5 the brain andspinal cord from harmful substancesspinal cord from harmful substances

2ermits entry of gases and nutrients2ermits entry of gases and nutrients


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;emember

; b; b


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;emember;emember

3unction of,3unction of,

'horoid ple*us'horoid ple*us

7rachnoid villi(granulations7rachnoid villi(granulations

Summary(


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Circulation of theCirculation of the

CS%:CS%:

y(

;evie/,

Ventricles


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Competencies:

> Describe the anatomical basis of theblood-brain barrier (BBB)

> Describe the formation of the Pacchionian

(arachnoid) granulations and their role inthe absorption of CSF

Competencies:The Ventriclar


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pS!stem

> Describe the ventricular system of the brain> 4ocate the sites of formation and absorptionof cerebrospinal fluid

> Enumerate the areas /here 'S3 is normally

found> 5race the flo/ of 'S3 from the area of

formation to the area of absorption

> State the usual site /here 'S3 is obtained

> State the composition and functions of 'S3

> Differentiate the mechanism of formation ofthe communicating and noncommunicating

types of hydrocephalus


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5han6 you5han6 you

;eferences,

'linical Neuroanatomy by ;ichard S Snell< Hth ed

4angmanJs Medical Embryology by 5 Sadler< Rthed


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Blood CS% Barrier:Blood CS% Barrier:


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Blood+CS% Barrier:Blood+CS% Barrier:

Q0 /ater< gases< lipid sol

@0 proteins< he*oses

layers

NS, Meninges, And Ventricles

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