i

mr* tr

1

;

o m a

ANATOMYOF THE

BRAIN AND SPINALSANTEE

CORD

ANATOMYOF THE

BRAIN AND SPINALWITH SPECIAL REFERENCE TO

CORD

MECHANISM AND FUNCTION

FOR STUDENTS AND PRACTITIONERS

BY

HARRIS

E.

SANTEE, M.

D.,

Ph.D.

PROFESSOR (.F ANATOMY IN THE COLLEGE OF PHYSICIANS AND SURGEONS, MEDICAL DEPARTMENT, UNIVERSITY OF ILLINOIS; PROFESSOR OF ANATOMY IN JENNBR MEDICAL COLLEGE, CHICAGO; MEMBER OF ASSOCIATION OP AMERICAN ANATOMISTS.

FOURTH EDITION, REVISED AND ENLARGED

WITH

128 ILLUSTRATIONS, 33

OF WHICH ARE PRINTED

IN

COLORS

PHILADELPHIAP.

BLAKISTON'S SON & CO.1012

WALNUT STREET1907

COPYRIGHT, 1907, BY P. BLAKISTON'S SON

&

Co.

Printed by The Maple Press,York. Pa.

PREFACETHEreceive

author hopes that the present edition of this work

may

from

his

colleagues

the

same generous considerationHis endeavor has beenof theto set

accorded to the former editions.forth the present status of thespinal cord.

anatomy

human

brain and

To do

this the facts

sources; and, so far as

was

have been gleaned from many possible, from the original sources.is

Being designed for a text-book, the subject-matterin the order found convenient to the dissector.

presented

description from the gross structures to the constituent neurones in proceeds each successive region. Wherever the embryology will assist the

The

student to comprehend the adult forms, the development is briefly given in the text but a special chapter is also devoted to embry;

which presents a concise and connected statement of the development of the entire brain and spinal cord.ology,

The

special objects held in view throughout the

book are the

location of functional centersassociative

and the tracing of

their afferent,

Particular emphasis is laid the origin, course, termination and function of conduction upon paths as they are met in the regular study, and the more important and better known of these paths are summed up in afinal

and

efferent connections.

chapter on the tracing of impulses.

Function

is

everywhere

correlated with structure;

and so far as present knowledge peris

mits, the function of each group of neuronestion withits

given in connec-

The

BNA

tion, the

without excepEnglish equivalents of the Latin terms being very largely

anatomical description. Nomenclature is followed almost

employed.lectures, every student is expected to brain in the laboratory, exposing, studying and sketching every macroscopic structure as it occurs in the work;

Keeping pace with the

dissect the

human

v

VI

PREFACE.

and, then with the microscope, examine the minute structure and For these purposes the picture the histology of the same parts.class should

be taken in smallbrain.

to four students,

sections, divided into groups of two and each group should be provided with a wellIt is desirable that

hardened

human

each student should

receive a well stained microscopic section of every important part. This is, however, often impossible; and the instructor may get

along with considerable satisfaction, by having the students exchange, if he has but a few sets of slides.

The authorliterature

and

wishes to acknowledge his indebtedness to recent to standard works on anatomy. McMurrich's

"Development of The Human Body," Barker's "BNA" and " Nervous System," the work of Dr. Alfred W. Campbell, Histological Studies on the Localization of Cerebral Func" the "Text-book of Anatomy" and "Memoirs of D. J. tion," R. S., and the fourth edition of Morris's " Human Cunningham, F.Barker's "

Anatomy" have beenI desire to express

especially useful.

my

colleague, Prof.

my Wm.

appreciation of the kindly assistance of T. Eckley, M. D.; and to say that the

new illustrations in this book belongs to my friend and pupil, Mr. Zan D. Klopper, of Chicago, who sketched the original drawings from my own specimens. My thanks areartistic

merit of the

also

due

to the publishers of this

favors

and

courtesies

select illustrations

little monograph, for many shown me, particularly for allowing me to from Gordinier, McMurrich and Morris, works

published by them.

HARRIS E. SANTEE.

TABLE OF CONTENTS.CHAPTERI.

THE MENINGES OF THE BRAIN.PAGE

Dura MaterStructure

of the Brain

:

i ii

and

relations

ProcessesSinuses

2-55

Arachnoid granulations (Pacchioni)Arteries

6-777

NervesContrasted with dura of spinal cord Arachnoid of the Brain:

88

StructureRelations, subarachnoid spaces. Vessels and nerves

8-9

99

Contrasted with arachnoid of the cord

Pia Mater of the BrainStructure

:

9

and

relations

9-1010

Chorioid tela of third and fourth ventriclesArteries

and veins

10-1313

NervesContrasted with pia of spinal cord Blood Supply of the Brain:Carotid and vertebral arteries

13

14-3014

A. Cerebral Circulation, ArteriesArterial circle(Willisi)

:

14-2 1

and branches

14-15

Ai. Cortical system of arteries Anterior cerebral artery

15-1816

Middle cerebral arteryPosterior cerebral artery Chorioidal arteries, posterior

16-1717

and anterior

A2. Ganglionic system of arteriesvii

17-18 18-21

Vlll

TABLE OF CONTENTS.PAGE

Antero-median ganglionic

arteries

18 18

Antero-lateral ganglionic arteries

Postero-median ganglionic arteriesPostero-lateral ganglionic arteries

18-21212

The Veins

of the

Cerebrum:

1-2421

Internal veins of the cerebrum

Great vein of the cerebrum (Galeni) External veins of the cerebrumSuperior

2

1-22

22-2322

MedialInferior

22-2323

Lymphatics of cerebrumB. Circulation of the Rhombencephalon:

23-24

24-3024

The medulla oblongata B2. The pons (Varolii) 63. The cerebellumBi.Superior cerebellar artery Anterior inferior cerebellar artery Posterior inferior cerebellar arteryInternal cerebellar veins

24-27

27-302

7-2829 2929

External cerebellar veinsSuperiorInferior

29-3029

29-3030

Lymphatics of cerebellumTableEmbryologic Divisions of the Brain Components of cerebrumI.

3~3333 33

Components

of

rhombencephalon

CHAPTER

II.

GENERAL CONSIDERATION OF THE BRAIN.Embryonic Brain VesiclesTheir cavitiesSuperior viewPosterior viewInferior view

34 34

the ventricles

34~35

35~3636-41

Anterior area

36-37

Middle areaPosterior area

37~3838-41

TABLE OF CONTENTS.Roots of the Twelve Cerebral Nerves:Nuclei, genetic and terminal Olfactory nerves

IXPAGE

42-4942

42

Optic nerve

42

Oculo-motor nerveTrochlear nerve

42-4545 45 45

Trigeminal nerve Abducent nerveFacial nerve

45-4645-4646

Intermediate nerveAcustic nerve

Glossopharyngeal nerve Vagus nerveAccessory nerve Hypoglossal nerve

46

46-494949

CHAPTER

III.

THE CEREBRUM.Subdivisions:

Enid -brainInter-brain

50 50 50

Mid-brain

SECTION

I.

THE

FORE-BRAIN OR.PROSENCEPHALON

50-1445 I- 98

Exterior surface of fore-brainDefinition of fissure

and sulcus

52 52525 2 ~735 2 ~55

Subdivisions and borders

Convex, medial and basal Fissures and sulci of convex surfaceLongitudinal fissure of cerebrum Transverse fissure of cerebrumLateral fissure of cerebrum (Sylvii) Sulcus centralis (Rolandi)Occipito-parietal sulcus. Lobes and gyri of convex surface

55

55-5656

56-5959~7359-63

Frontal lobe,

and sulci Parietal lobe, its gyri and sulci Occipital lobe, its gyri and sulciits

gyri

63-67

67-69

TABLE OF CONTENTS.PAGE

Temporal

lobe, its gyri

and

sulci

69-7 170 70-71 7 I- 73

Superior surface External surface

The

Island (Reili), its sulci and gyri base of the fore-brain

73-85

Frontal lobe, inferior surface Island (Reili), inferior surface

73-7474~77

RhinencephalonOlfactory lobe

77~79 77~79 77~78striae

Olfactory bulbOlfactory tract and

78 79

Olfactory triangle Parolfactory area (Brocae) Anterior perforated substanceTentorial area of basal surface

7979

Chorioidal

fissurefissure

79-82 80

Hippocampal

8080-8181 8181

Ectorhinal sulcusFissura collateralisInferior temporal sulcus

Gyrus Gyrus lingualis Limbic lobe, inferior part Gyrus hippocampi and uncusDentate fasciar

fusiformis

81

81-82 81-8282

HypothalamusPars optica hypothalami

'.

82-85

82-8483

Lamina

cinerea terminalis

Optic chiasma, nerves and tracts Tuber cinereum and infundibulum

83-8484

Hypophysis (pituitary body) Pars mammillaris hypothalamiCorpora mammillaria Fissures and sulci of medial andSulcus cinguliSubparietal sulcus Callosal sulcusOccipito-parietaltentorial surface

8482

and 8484 84-98 86 86 86-89

(calloso-marginal)

sulcus

89

Calcarine fissure

89-9090

Hippocampal

fissure

TABLE OF CONTENTS.Chorioidal fissureCollateral fissure

XI PAGE

90

Ectorhinal sulcusInferior temporal sulcus Gyri of medial and tentorial surface

9~93 9~9393

93-9893~97

Gyrus fornicatus

Gyrus cinguli Gyrus hippocampi Uncus Lobus pyraformis Limbic lobe, rhinencephalon..

93~9494~97

94-9797

9797

Gyrus rectus Gyrus frontalis superior Lobulus paracentralisPrsecuneus(g.

marginalis)

9797 9797

CuneusGyrus lingualis Gyrus fusiformis

97 97

Summary

of lobes of the

cerebrum

98 98

NeopalliumRhinencephalon(archipallium),

98 98

Corpus striatumInterior surface of the fore-brain

98-144 99-104 99-100100 100

Internal capsule Inferior lamina

Motor

fibers fibers

Sensory Superior lamina

100-104occipital parts

Genu, frontal and

103

Motor

fibers

103

sensory fibers sense fibers Special Corpus callosum:

Common

103-104104

104-108107 107 107

Upper

surface

Gyri supracallosus and subcallosusInferior surface

Borders, posterior and anterior Splenium, rostrum, genu, truncus

107-108 108108-109109

Boundaries of general cavity of fore-brain

Body

of fornix

Xll

TABLE OF CONTENTS.PAGE

Crus

fornicisfornicis

Columnae

no no111

Septum pellucidumFifth ventricle

111-112its

Lateral ventricle andCentral part (body) Corpus striatum

boundaries.

112-127 1 12-120 115-119 1161

Lentiform nucleus

Nucleus caudatusStria terminalis

16-119119119 120

ThalamusChorioid plexus of lateral ventricle Anterior horn of the lateral ventriclePosterior hornInferior1

20-1 23123

horncollateraleits

123-127124

TrigonumChorioid

Hippocampus,

digitations

124124

epithelium.

Third Ventricle and Inter-BrainPosterior commissure

127-144132132

Roof epithelium Pineal bodyChorioid tela of third ventricleAnterior commissure

132-135

135-136 136-139139

Lamina terminalis ThalamusExtremities

-.

139-143".

Surfaces

anterior and posterior medial, superior, lateral

.

140

and

inferior..

140-143143 143143

Tegmental hypothalamic region Nucleus hypothalamicus (Luysi)Lateral geniculate body

Medial geniculate body

143-144:

SECTION

II.

THE MID BRAIN (MESENCEPHALON)superior, inferior, anterior, posterior

144-164

Surfaces

144-146147-151148 148

Bases pedunculi Intermediate bundle

Temporo-pontalPyramidal tract

tract

148-151151

Fronto-pontal tract

TABLE OF CONTENTS.Substantia nigra.

Xlll

PAGE

151

TegmentaCerebral aqueduct (Sylvii)

152-163152

Nuclei of oculo-motor and trochlear nerves

152-155155

Mesencephalic nucleus of trigeminal nerveFormatio-reticularis

155-163155

Tegmental decussationsTracts of fibers in the tegmentum

155-163

Medial

(or posterior) longitudinal

bundle

155-158

Anterior longitudinal bundle Fillet or lemniscus

158-159159-161

MedialLateral

fillet fillet

superior

fillet.

159-160 160-161161-162162162 162

Spino-thalamic tract.

Brachium conjunctivumRubro-spinal tractOlivary fasciculus

Descending root of trigeminal nerve Quadrigeminal laminaColliculus superior

163

163-164163

Colliculus inferior

163-164-

Brachium superius Brachium inferiusSECTIONIII.

164 164

STRUCTURE OF THE CEREBRUM:or nerve cell

164-241167-1 73167 167 168

The neuroneDendrites

Cell-body, perikaryon, or neurone center

AxoneMyelin sheath

168 168

Types

of neurones (three)(ist, 2d, etc.)

Orders of neurones

168-171171

Functions of neurones

Degeneration of neurones Development of neuronesSustentacular tissue.

171-172

172-173173

Epiblastic

173-174173-174174

Neuroglia and ependyma Mesoblastic connective tissueCortical gray matter

174-204

XIV

TABLE OF CONTENTS.PAGE Cortical or cerebral localization

177-183177

Motor

area, emissive

Psychic motor area Common sensory area

178178178 181181 181

Psychic sensory area Acustic center

Optic centerOlfactory and gustatory centers

Naming

center

18118 1

Centers of intonation, equilibration and orientationAnterior association center, abstract conceptions Posterior association center, concrete conceptions

182

182-183183

Middle association centerCell

and

fiber lamination

183-204184-187 184 and 187184 and 187 184 and 187-188 184 and 188 184 and 188-191 184 and 191192.

Plexiform layer Layer of small pyramids

Layer of medium-sized pyramidsExternal layer of large pyramids

Layer of

stellate cells

Internal layer of large pyramids Layer of fusiform cells

Radiations of Meynert Association fibers of MeynertAtypical cortex: Visual cortex

192

192-204192-195

Olfactory cortex

195-204195-196196-199199

Olfactory bulb

Uncus hippocampiNucleus amygdalae SubiculumFascia dentataolfactorium, etc

199

200200-203203

Trigonum

Gyrus cinguli ClaustrumGanglionar gray matter

204

204-221

Corpus striatumCentrifugal fibersCentripetal fibers

204-208207-208 208208-217 208-211

ThalamusThalamic nuclei...

TABLE OF CONTENTS.White matterCorticalof the thalamus

XVPAGE

211-217

fillet

216-217217 217 217 218

Occipito-thalamic radiation (optic) Temporo-thalamic radiation (acustic)

Red nucleus...Nucleus hypothalamicus MetathalamusLateral geniculate body

218218

Medial geniculate bodySuperior colliculi of corpora quadrigemina Anterior longitudinal bundleInferior colliculi of corpora quadrigeminalateralis superior Substantia nigra Central or ventricular gray matter

218-219

219-220 219-220 220220221

Nucleus

HypothalamusPars optica Pars mammillaris

221-224 221-222221

221-222222

Massa intermedia (middle commissure)Stratum griseum centrale of mid-brain Oculomotor nucleusTrochlear nucleus

222-224223

223

Trigeminal nucleus of mid -brain Projection fibers of the cerebrumCorticifugal, or

224

224-234225-231225 225

motor

fibers

Intermediate tract

Fronto-pontal tract

Tempora-pontalPyramidaltract

tract

225-226226-231227 228

Head and neck

fibers

Upper extremity fibers Trunk fibers Lower extremity fibersDestruction of by clot, etc Sensory or corticipetal fibers

228'

228-231231

231-234231

Medial

fillet,

spino-thalamic tract and brachium con-

functivumOlfactory projection fibersCorticalfillet

232

(common

sensory)

232-233233

Taste fibers (not located)

XVI

TABLE OF CONTENTS.PAGE

AuditoryLateralfillet

233

and brachium

inferius

233233

Temporo-thalamic radiationOccipito-thalamic radiation (optic)

234

Commissural

fibers of

cerebrum

234-236234

Corpus callosumAnterior commissure

234-235236

Commissura hippocampiAssociation fibers of cerebrum

236-241

Short association fibers

236-238238-241238

Long

association fibersof gyrus fornicatus

CingulumFornix

238-240 240240240-241241 241

Uncinate fasciculusSuperior longitudinal fasciculusInferior longitudinal fasciculus

Fasciculus occipito-frontalis

Perpendicular fasciculus

CHAPTER

IV.

THE RHOMBENCEPHALON.SECTIONFunctionDivisions:

I.

THE CEREBELLUM:

242-266342 242

Cerebellar hemispheres Vermis cerebelli or worm

242-243243

Cerebellar notches, anterior and posterior

244

Medullary Body:Inferior medullary velum Brachia conjunctiva

244-247244245

Superior medullary velum (Vieussertsi)

246

Corpora restiformia Brachia pontisHorizontal sulcus of cerebellumSuperior Surface of CerebellumSulci of:

246-247247

247-248248-25 1

upper surface Precentral sulcusPostcentral sulcus

248-249248 249

TABLE OF CONTENTS.Predeclivil sulcus

XV11 PAGE

249 249

Postdeclivil sulcus

Lobes of superior surface Lobus lingulae Lobus centralis Lobus culminis monticuli Lobus declivis monticuli Lobus folii vermisInferior Surface of Cerebellum:Sulci of lower surface

250-251

250

250250251 251

251-256252-253252

Postnodular sulcus

Prepyramidal sulcusPostpyramidal sulcusMidgracile and postgracile Lobes of lower .surface

252-253253

253

253-256253-254254

Lobus noduli Lobus uvulae Lobus pyramidis Lobus tuberisCortical

254-255

255-256

Gray Matter

of the Cerebellum

256-260 256-258256257.

Superficial layer

Stratum cinereum Stratum gangliosumCells of Purkinje

and

stellate cells

257

Fibers of superficial layer

257-258

Deep

layer (stratum granulosum) Cells of granular layer

258-260

Fibers of granular layer

258-259 260cells

Function of

stellate,

granule and Purkinje

260

Neuroglia of cerebellum

260260-26226026.0-261

Ganglionar Gray Matter of CerebellumFunction, relay stations

Nucleus dentatus

Nn. emboliformis, globosus and fastigii White Substance Corpus Medullare:Projection fibers

261

262-266 263-265263

Brachium conjunctivum Superior medullary velum Brachium pontisCorpus restiforme

263-264264

264-265

XV111

TABLE OF CONTENTS.PAGE

Commissural

fibers

265

Association fibers

265-266(VAROLII)

SECTION

II.

THE PONS

266-284 266-270 266266-269

Surfaces:

Superior and inferior Anterior (Tuber annulare)Posteriorventricular,fibers of the

and attached partpons

269-270271-272271 271

Transverse

Superficial of pars basilaris pontis

Deep

transverse of pars basilaris pontis

Transverse of pars dorsalis pontis

271-272272

Trapezoid bodyLongitudinal fibers of the pons Ventral

272-278272

Dorsal

272-278filletfillet

MedialLateral

and superior

fillet

273-274272 272tract

Spino-thalamic tract

Ascending anterior cerebello-spinal Gowers's tract

272-276276

Medial longitudinal bundle Anterior longitudinal bundleRubro-spinal tract Olivary bundleSpinal tract n. trigemini of the pons,

276276

276-277277 277

Descending root of trigeminal nerve

277

Gray Matter

277-284277

Nucleus pontis Stratum nucleareSuperior olivary nucleus

278-284278-279279279

N. praeolivaris and n. semilunaris Nucleus of trapezoid body.Nuclei of recticular formationPonto-spinal tracts (Collieri) Nuclei of trigeminal nerve

279-280 280281 281 281

Genetic (motor)

Terminal (sensory)Nucleus of abducent nerve

281-282282

Nucleus of

facial nerve..

TABLE OF CONTENTS.Salivary nucleus Vestibular nucleus of auditory

XIXPAGE

283283

Lesions in pons

283. .

SECTION

III.

MEDULLA OBLONGATA (MYELENCEPHALON)

2-84-313

OriginVentricle-. .

285 285

Surfaces

Anterior lateral sulcusPosterior lateral sulcus

286-290 286286

Anterior

surface

286-287

Lateral surface Olive Lateral columnPosterior surface

287-288287

287-288

Restiform body

288-290 288of fourth ventricle

Roof epithelium

289

Floor of fourth ventricle

290

White matter

of medulla

290-302291

Substantia reticularis

RapheTransverse fibers

291

291-292291

Pyramidal decussation Arcuate fibers, external and internalFillet

291-292292 292

decussation

Cerebello-olivary fibers

Dorso-ventral fibersAnterior external arcuate

292-293

'292293

Roots of eighth

to twelfth cerebral nerves

Longitudinal fibers of anterior area:

293-298 294295

Pyramid, anterior and lateral tracts Medial fillet (interolivary stage)

Medial longitudinal bundle (posterior) Anterior longitudinal bundleLongitudinal fibers of lateral area Fasciculus lateralis proprius

296297

298-300298tract

Descending anterior cerebello-spinalAscending anterior cerebello-spinal

298299

tract

Rubro-pinal

tract

300300-302

Longitudinal fibers of posterior area

XX

TABLE OF CONTENTS.PAGE

Funiculus gracilis Funiculus cuneatusSpinal tract of trigeminal nerve(Posterior) Cerebello-spinal tract

300

300301 301

Restiform body Vestibular and cochlear nuclei

301 302 302

Tractus

solitarius

Gray matter

of the medullafibers

302-3 13302nucleare)

Nucleus of external arcuateNuclei in floor of ventricle(s.

303-310303

Hypoglossal nucleus Nucleus lateralis inferior

303-304

Nucleus ambiguusNucleialae cincereae

303-304 304 and 306306 306n. trigemini

Nucleus tractusVestibular nuclei

solitarii

Nucleus tractus spinalisCochlear nucleiSpecial nuclei in medulla

307-308309-3 103 10-3 13

Nucleus funiculi Nucleus

gracilis

310-311 310-3113123 I 3~3 2 5

Nucleus funiculi cuneatiolivaris inferior

SECTION IV.

THE FOURTH VENTRICLE

BoundariesFloor of fourth ventricleColliculus facialis

313-314314-318317 317317 317 317

Fovea superior* Locus cseruleusHypoglossal triangle Ala cinerea (trigonum vagi)

Area acusticaOrigin of cerebral nerves

320

320-325320-321

Sensory Nerves and Roots Table III. Motor Nerves and Roots

Table

II.

321-322

Terminal nuclei

322-324322 322.

CommonCortical

sensory

and

reflex connections

Special sense Cortical and reflex connections

322-324324

TABLE OF CONTENTS.Genetic nuclei.

XXIPAGE

324-325reflex connections

Cortical

and

324-325

CHAPTER V. MEMBRANES OF THE SPINAL CORD.Dura materArachnoidPia mater

326

326-3293 2 9~33:

Blood Supply of the Spinal Cord Spinal arteries, anterior and posteriorFissural or centrifugal

33~33 2 33~33 233133 I- 33 2

Centripetal

Venae spinales internae

332332 332 332

Root and

fissural veins

Venae spinales externalInternal vertebral plexus

Lymphatics

332

CHAPTER VI. THE SPINAL CORD.ExtentDiametersCervical enlargement,

333

333~335

333~334334~335337

Lumbar enlargementSixth ventricle (canalis centralis spinalis) Fissures of the cord:

337~33&337

Anterior median fissurePosterior

median

fissure

337

Posterior lateral sulcus

337~33&338 338

Anterior root-line

(s.

lateralis anterior)

Posterior intermediate sulcusr.

Gray Matter of the Cord: H-shaped columnSubstantia gelatinosa Substantia spongiosa

338-351339

339339:

Gray

crescent

339~349 339~344 340-344

Anterior columnaCells of anterior

columna

XX11

TABLE OF CONTENTS.PAGE

Golgi cells Deiters cells

340340 340340, 343-344

Medial columnLateral columnCortical connection

343

Reflex mechanism

343~344

Lesions of anterior columna

344lateralis

Center of crescent and columnaIntermedio-lateral

344-347(efferent

column

of

cell-bodies

sympathetic neurones)Posterior

344-347

columna Neurones of head of posterior columna Nucleus dorsalis (Clarki) terminal nucleuspathetic)

347-349 347-348of

sym348-349

Gray commissure of spinal cord Gray anterior commissurePosterior commissure

350 350

350350351-362351 35135 1 ~35 2

Lesions of gray substance2.

White Matter of the Spinal Cord:Transverse fibers

White anterior commissureDorso-ventral fibers

Longitudinal fibers Funiculus anterior

352. .

352352 352352 352

Funiculus

lateralis

Funiculus posterior

Ascending

tracts tracts

Descending

Mixed

tracts

35235 2 ~353

Embryological method of locating tracts Pathological and experimental method Tracts of the Spinal CordAntero-lateral fasciculus proprius

353

354-362

354 354355355tract

Medial longitudinal bundleAnterior pyramidal tract Anterior longitudinal bundle

Descending anterior cerebello-spinalAscending anterior cerebello-spinalSpino-thalamic tract

3563 56-3 5 7

tract

356-357357

Triangular tract of Helwig

TABLE OF CONTENTS.(Posterior) Cerebello-spinal tract

XX111

PAGE

357~35&357~358358

Spino-vestibular tract Lateral pyramidal tract

Rubro-spinal tract Lesions of anterior and lateral funiculi

358359 359

Marginal tract (Lissaueri) Entry zoneFasciculus gracilis (Golli)

359~36o360-361361 361

Fasciculus cuneatus (Burdachi)

Descending

tracts

from posterior roots

Descending postero-medial tract (comma, oval, septomarginal and median triangular tract) Descending postero-lateralPosterior fasciculus propriustract

361 362 362

Cornu-commissural tractLesions of posterior columns

362362

Roots of the spinal nervesAnterior root

362-365363 363

Apparent origin Real origin (genetic nuclei) Voluntary motor fibersSympathetic efferent fibers LesionsPosterior root

363 363363

360-364364-365

Spinal ganglion (origin) Apparent central termination

364364 364364-365365

Real central termination, terminal nuclei Gray matter of the cordNuclei of medulla oblongataPhysiological groups of posterior root-fibers Lesions of posterior roots

365365

CHAPTERI.

VII.

TRACING OF IMPULSES.Efferent, or

Motor Paths:

:

366-374366-369366 369

Cerebro-spinal or pyramidal paths Through spinal nerves

Through

cerebral nerves

Cerebro-pontal pathsFronto-pontal

369-370

370

XXIV

TABLE OF CONTENTS.PAGE

Temporo-pontalIntermediateSpinal and cerebral Paths through red nucleus

370

370 370

Rubro-spinal path, directIndirect via

37~373 37~373373 373

brachium conjunctivumtract

Ponto-spinal paths (Collieri)

Medial ponto-spinal

373373

II.

Lateral ponto-spinal tract Short fiber paths in formatio-reticularis Afferent, or Sensory Paths, General Sensations:Tactile, muscular, pain,(I).

373~374377-383377skin,

and temperature sense Muscular and tactile impulses from muscles,etc fasciculi gracilis et cuneati

377-38i

Through

377~378378 378

Direct routeIndirect route

Through(II).

cerebral nervestactile

Muscular and

and medial fillet impulses from visceratactile

378-381..

381 381

Through(III).

posterior cerebello-spinal tract

Paths for pain, temperature and

impulsestracttract

..

381-382

Through spino-thalamic tract Through ascending anterior cerebello-spinal Through cerebral nerves and spino-thalamicShort fiber paths Afferent Paths Special Sensations:Olfactory path

381-382 381-382382

382-383

383-390383-384384-3 8 5

Optic path

Auditory path Cochlear (hearing proper)Vestibular (equilibrium) Reflex connections

385-389386

386-389389 389

III.

Gustatory path Lesions of special sense paths Reflex Paths:

389-390390^394390

Reflex arcs(1) Spinal reflexes

39-39 2390391-39239 2 ~393

Coordinating reflexes Defecation reflexes(2)

Cerebral reflexes

TABLE OF CONTENTS.Spino-cerebral reflexes

XXV

PAE(3) (4)

393

Cerebro-spinal reflexes

393~394393

Respiratory reflexes

Equilibrium reflexesPupillary reflexes

393

394

CHAPTER VIII. EMBRYOLOGY OF THE BRAIN AND SPINAL CORD.Medullary plate and ridges Neural Tube:Brain vesiclescells'.

395

395-400 395 and 402397

Ependymal

Indifferent cells

397~398398

Neuroblasts, neuronesSpongioblasts, neuroglia

398-399

Zones, roof-plate and floor -plate

399-400400-401: ..'

Neural Crest

:

Cephalic portion Cerebral nerve ganglia

400 400400-401401

Unipolar and bipolar neuronesSpinal portion of crest

THE

BRAIN:Flexures

401-426402 403

Table IV. Brain Vesicles and Derivatives Table V. Secondary Brain VesiclesTelencephalon (end-brain) Table VI. Derivatives ofOpticvesicle,

403-404404-415404-405405

cup and retina

Hemisphere of cerebrum RhinencephalonPrimaryfissures

405-415 406-409

Secondary sulci and fissure Transverse fissure of cerebrumCerebral cortex and medulla

409-410 410-41141141 1-412

FornixStria terminalis

412

412

Internal capsule

412-413

Anterior commissure

413-414

Corpus callosum

414

XXVI

TABLE OF CONTENTS.PAGE

Septum pellucidumPars optica hypothalami

415

415

Diencephalon (inter-brain) Table VII. Derivatives ofRoof-plate

415-417415 416417 417

Dorsal laminaVentral lamina and floor-plate

Mesencephalon (mid-brain) Table VIII. Derivatives ofMetencephalon (hind-brain) Table IX. Derivatives ofCerebellum

417-418

417-418 418-424419418-421

Vermis and hemispheriaSulci

419-420 420-42 142 1

Cortex and ganglia

Corpus restiforme and brachia Pons (Varolii)Myelencephalon (medulla oblongata)Internal surface

42142 1-422

422-426423

External surface

Table X. Derivatives of Myelencephalon

423-424 424424-425425

Ependymal

layer.

Mantle layerNeuroglia layer, marginal velum

425-426

THE

SPINAL CORD:

Ventriculus terminalis

426-430 426426 426 426

Filum terminale

Cauda equinaMeningesZones, ventral and dorsalHistologic layers

426-427

Marginal velum, neuroglia layer Mantle layer

427-428 428428-429429

Ependymal

layer

Longitudinal tracts Order of medullationFissures of cordPosterior

429-430 429-430

430fissure

median

430 430430

Posterior lateral sulcus

Anterior median fissure

LISTFIG.

OF ILLUSTRATIONS.PAGB

1.

Sagittal section of skull,

showing falx

cerebri, falx cerebelli,

a part of the tentorium cerebelli and the sinuses of the dura mater. (After Morris's Anatomy)2.

3

Upper

surface of tentorium cerebelli, tentorial notchtain sinuses of the dura.

and

cer. .

(After Morris's

Anatomy)

4

3.

Sinuses of the dura mater in the base of cranium, etc. Morris's Anatomy)

(After5

4.

Coronal section of meninges showing falx cerebri, superior sagittal sinus and the arachnoid granulations. (Gordinier after

Key and

Retzius)

6

5.

6.

Middle meningeal artery inside the cranium. (After Morris's Anatomy) Diagram of pia mater and arachnoid, showing subarachnoidspaces.

7

(After Morris's

Anatomy)Fornix turned back to

9

7.

Horizontal section of the cerebrum.

8.

show the chorioid tela of third ventricle. (Original), Roof and lateral walls of fourth yentricle and its chorioidplexus.(After Morris's

n13

Anatomy)branches.

9. Arterial circle of Willis

and

its

The

base of the15(After

brain.10. Arterial circle

(After Morris's(Willisi)

Anatomy) and base of the cerebrum.

n. Middle12

Gordinier from Quairi) cerebral artery, and its branches.

19(After Gordinier

from Quairi)Anterior and posterior cerebral arteries.13. Arteries of the 14.

22 2527

Median McMurrich from His)omy) Neural tube and brain

(After Spalteholz).. (Gordinier after Duret) ... section of embryonic brain of third month. (After

medulla oblongata.

28(After Morris's Anat-

15. Divisions of the brain, diagrammatic.

31vesicles.

16.

(After Morris's

Anatomy)..

35

17.

Diagrammatic horizontal section of vertebrate brain, showing vesicles and ventricles. (After Morris from Huxley)xxvii

36

XXV111FIG.

LIST OF ILLUSTRATIONS.PAGE

18.

Diagrammatic median section of vertebrate brain showing vesicles, ventricles and olfactory diverticulum. (After Morris from Huxley)(Original)

37 394347

19. Antero-superior surface of the brain.

20.21.

The posterior aspect of the brain. The base of brain. (Original)lobes, poles

(Original)

22. Latero-superior

aspect of the brain, showing great fissures, and borders. (Original)

53

23.

The convexsulci.

surface of the cerebrum, showing the fissures(Original)

and57 61

24.

Gyri of the convex surface of the cerebrum.are cut

(Original)

25. Lateral aspect of the brain.

Part of frontal and parietal lobes

island (Reili) and the superior surface of the temporal lobe, arachnoid granulations,

away

to

show the

etc.

(Original)

65

26.

Base of the fore-brain and cut surface of mid-brain.temporal poleis

Right75

cut away.

(Original) (Original)

27.28.

The mediansulci.

section of the brain.left

87

Medial surface of

cerebral hemisphere, showing lobes

and91

(Original)

Gyri on medial surface of hemisphere. (Original) Transverse section of the brain, directed from the pons ob30.29.

95

upward and forward, showing internal capsule, corpus callosum, ganglia and ventricles of the foreliquely

brain.

(Original)

101

31. Horizontal section of right cerebral hemisphere cutting corpus

callosum, internal capsule, corpus striatum, thalamus,

and theshowing33.

island.

(Original)

105

32. Sagittal section of basal part of right cerebral hemisphereinferior

lamina of internal capsule, hippocamlateral ventricle.

pus, inferior

horn of

(Original).

.-..

113

Diagram

of internal capsule in colors.

(Original)

115

34. Dorsal surface of corpus callosum, cerebral

hemisphere cut117

away

to

expose

it.

(Original)

35. Horizontal section of cerebrum, cutting

splenium and genu of(Orig-

corpus callosum, showing lateral ventricles, septum pellucidum, fornix and transverse temporalinal)36. Horizontal section ofgyri.

121

below splenium of corpus callosum, showing commissura hippocampi, fornix, sepjust

cerebrum

LIST OF ILLUSTRATIONSFIG.

XXIXPAGE

turn pellucidum, the islandiginal)37. Horizontal section of cerebrum.

and

lateral ventricles.

(Or125

Fornix turned back, showing

chorioid tael of third ventricle,veins.38. Transverse

and

internal cerebral

(Original)section of left cerebral hemisphere cutting the

129

39.

The

splenium and showing the posterior horn and the floor horn of the lateral ventricle. (Original) 131 inferior' and posterior horns of the lateral ventricle, shownof the inferior

by removal

of their lateral walls.

(Original)

133

40. Horizontal section of cerebrum through genu and below splenium of corpus callosum, fornix and chorioid tela turned

back, to show' inter-brain and third ventricle.iginal)41. Lateral

(Or-

137of the ventricles.

and dorsal view

Diagrammatic.141

(Original)42. Transverse

section of brain, cutting corpora mammillaria.

43.

The

(After Told. Morris's Anatomy) 145 region of the mid-brain showing pulvinar of the thalamus, the geniculate bodies, the corpora quadrigemina and

brachia, the pineal body, the optic tractnerve.44.

and the fourth147

(Original)

The

dorsal or posterior aspect of the inter-brain, the the pons and the medulla. (Original)

mid -brain,149(Orig-

45. Anterior aspect of the

mid -brain, pons, and medulla.

inal)

153

46. Transverse section through the corpora

mammillaria and the.(Orig-

superior colliculi of the corpora quadrigemina.inal)

157

47. Section of the mid-brain through superior colliculi

and the ap159161(After

parent origin of the oculo-motor nerve.

(Original) ..

48. Section of the mid-brain cutting the inferior colliculi of the cor-

pora quadrigemina.49. Varieties of neurones in the

(Original)

human

nervous system.

50.

Motor neurone.

51.

An

Morris's Anatomy) 165 169 (After Barker's Nervous System) efferent neurone and an afferent neurone. (After Brubaker's Physiology)

171in the spinal cord.

52.

Diagram showing 'development of neurones (McMurrich after Schaffer)

172

XXXFIG.

LIST OF ILLUSTRATIONS.PAGE

53.

Neuroglia

54.

and ependyma cells of the spinal cord. Lenhossek, Gordinier's Nervous System) Cortical areas on convex surface of cerebral hemisphere.cells

(After

173(Or-

iginal)55. Cortical areas

175

on the medial andK. Mills.

tentorial surface of the cere-

bral hemisphere.56. Cortical areas after C.

(Original)

179of cerebral

Convex surfaceMedial and

hemisphere.

(Brubaker's Physiology)

182tentorial surface

57. Cortical areas after C.

K. Mills.

of cerebral hemisphere.58. Cell

(Bmbaker's Physiology)area.

183

and

fiber lamination in the posterior half of the anterior

centralbell)

gyms.

The motor

(After

A W. Camp.

185

59. Cell

and

fiber lamination in the anterior half of the posterior

central

gyms. The A. W. Campbell)(After

common

sensory area.

(After

189 Receptive

60. Cell

and and

fiber lamination in the calcarine region.

visual area.61. Cell

fiber lamination in the

formis).

A. W. Campbell) 193 uncus hippocampi (lobus pyraThe area of smell. (After A. W- Campbell) 197hippocampal region. (After Edinger) 201(Gordinier after

62. Transverse section of the

63. Chief elements of the olfactory bulb.

Van203

Gehuchteri)64. Horizontal section of the

cerebrum through genu and below of corpus callosum, fornix and chorioid tela splenium turned back to show inter-brain and third ventricle.(Original)

205

65. Dissection of brain to

show geniculate

bodies, optic tract,

66.

nucleus amygdalae, etc. (After Morris's Anatomy) 207 Transverse section of the brain in the line of the pyramidaltracts,

showing basal ganglia, internal capsules, corpus Viewed callosum, lateral and third ventricles, etc.

from67.

front.

(Morris's(Original)

Anatomy

after Toldt)

209213

The

optic path.

68. Section of

mid -brain through superior

colliculi

and the appa215 216

rent origin of the oculomotor nerve.

(Original)

69. Section of the mid-brain cutting the inferior colliculi of the cor-

pora quadrigemina.70. Horizontal

(Original)

and

sagittal section through internal capsule,

much226

enlarged.

(Original)

LIST OF ILLUSTRATIONS.FIG.

XXXIPAGE

71. 72.

Diagram

of internal capsule in colors.

(Original}

227

A

diagram showing motor and sensory paths, motor red, (After Gordinier's Central Nervous sensory blue.

73.

System) 229 Transverse section of cerebrum, cutting corpus callosum, anterior commissure and optic chiasma. Viewed fromfront.

Commissural

fibers.

(Morris's

Anatomy

after

Toldf)74.

-.235

Diagram

of association fibers in the cerebral hemisphere.

(Gordinier and Quain after Meynert) 237 Fasciculus occipito-frontalis. Stria terminalis and fasiculus 75. uncinatus. (Gordinier after Dejerine) 239 Su76. Dorsal view of inter-brain, mid-brain and cerebellum.perior surface of cerebellum.77. Anterior aspect of cerebellum.78. Dissection of

(Original)

243

(Original)

245

79.

rhombencephalon to show brachium conjunctivum, brachium pontis and corpus restiforme. (Gordinier, Sappey after Hirschjeld and Leveille) 246 Median section of cerebellum, pons and medulla. (Original) 247(Original)

80. Inferior surface of cerebellum.

252(Or-

81. Sagittal section of cerebellum, cutting nucleus dentatus.iginal)

255

82. Section of cerebellar gyrus

made

parallel with its free border.after Kolliker)

Diagrammatic.border.ten)

(Cunningham

258

83. Section across a cerebellar gyrus at a right angle to the free

Diagrammatic.

(Gordinier after

Van Gehuch259

84. Horizontal section of cerebellum cutting nuclei

and brachia261(After

(Morris's Anatomy after Toldf) conjunctiva. Anterior aspect of mid-brain, pons and medulla. 85. Morris's Anatomy)86.

267

Dorsal surface of pons and medulla. modified from Spalteholz)

(Morris's

Anatomy270275

87. Superior transverse section of the pons.88. Inferior transverse section of the

(Original)

pons together with the cere277(After Morris's

bellum.89.

(Original)

Diagram

of the auditory paths in the pons.

Anatomy)90. Section of embyronic medulla,

280

embryo measuringMinotafter

9.1

mm.

in

length.

(Gordinier and

His)

285

XXX11FIG.

LIST OF ILLUSTRATIONS..

PAGBits

91.

Roof and

lateral walls of fourth ventricle,

and

chorioid

(After Morris's Anatomy) 289 medulla oblongata near the pons. (Original) 295 (Or93. Section of the medulla oblongata at the middle of olive.

plexuses.

92. Section of

.

.

.

iginal)94. Section of the

297

medulla oblongata at the

fillet

decussation. (Or-

iginal)95. Section of the medulla oblongata at the pyramidal decussation.

305311

(Original)96. Nuclei of the cerebral nerves in the medulla, pons, mid-brain,

Motor (or genetic) inter-brain, and olfactory bulb. nuclei red, terminal (or sensory) nuclei blue. (AfterMorris's Anatomy) 315 A. Transverse section. (After 97. Meninges of the spinal cord. Key and Retzius.) B. Anterior view. (After Ellis.)(Morris's Anatomy) 327 Diagrammatic section of the spinal meninges and spinal cord. (After Morris's Anatomy) 329 The arteries and veins in the spinal cord. Diagrammatic. (After Morris's Anatomy) 331 Posterior view of the spinal cord, the dura mater and the arach-

98.

99.

100.

noid being laid open and turned aside.after

(Brubaker

Sappey):

334A.

101. Sections of the spinal cordcic.

The

cervical.

B.

The

thora-

C.

The lumbar, and D. The lowerand columns

sacral.

(Or-

iginal)

335of cells, in the cervical

102. Tracts of fibers

and thora-

Diagrammatic. (In part after Bruce and Cunningham) 341 103. Tracts of fibers and columns of cells in the lumbar and sacralregions of the cord.

cic regions of the cord.

Diagrammatic. Bruce and Cunningham)104.

(In part after

345(Original). 349

The

roots of the spinal nerves.

Diagrammatic.

105. Direct

motor paths from cerebral cortex,nal nerve.

to cerebral

and

spi-

367 (Original) 106. Indirect motor paths to the spinal nerves. Diagrammatic.(Original)107.

Diagrammatic.

371tactile,

Common

sensory paths, muscular and

by way

of the

posterior

column and

(posterior) cerebello-spinal tract.

Diagrammatic.

(Original)

375

LIST OF ILLUSTRATIONS.FIG.

XXX111

PAGE

108.

Common

sensory paths, pain, temperature and touch, bytracts.

way379

of ascending anterior cerebello-spinal

and spino-thala-

mic

Diagrammatic.

(Original)

109. Chief elements of the olfactory bulb.

(Gordinier after

Van384

Gehuchten)

no. The in. The112.

chief retinal elements.

(After Brubaker' s Physiology) .. 385

optic path.

(Original)reflexarc.

387(Brubaker after Moral and391

A A

simple

spinal

Dayori)113.

more complicatedproprii.

spinal reflex arc, involving the fasciculi

(Brubaker after Kolliker)etc.

392

114.

Medullary groove, neural tube,Schd/er)

(Gordinier after E. A.

396

115.

Two

histologic layers in the

embryonic spinal cord, embryo

116.

117.

4.25 mm. long. (McMurrich after His) 397 Diagram showing development of neurones in the spinal cord. (McMurrich after Schafer) 398 Ventral and dorsal zones of the spinal cord. (Gordinier and

118.

Quain after Kolliker) Median section of embryonic brainMurrichafter

399of the third

month.

(Mc406

His)

119. Transverse section through the fore-brain of a four

and oneHis) 407409

half weeks' embryo.1

(Gordinier

and Quain

after

20.

DiagrammaticMedial

sagittal section of vertebrate brain.

(Morris's

Anatomy121.

after

Huxley)through the brain of an embryo offissures

sagittal section

three

months showing the primitive

on the411

medial surface of the cerebral hemisphere.rich after Mihalkovicz)122.

(McMur-

The

fossa

cerebri

month.

embryonic brain of fourth McAfurrich's Development oj the Human (Afterlateralis,

in

123.

Body) Permanent fissures and sulci on the convex surface cerebrum as seen in a seven months' embryo. Murrich after Cunningham]tricles

413of the

(Mc414

124. Dorsal view of

an embroynic brain, the roof of the lateral venhaving been cut away. Embryo of 12.6 mm.after

(McMurrich (McMurrich

His)

416

125. Transverse section of

medulla from an embryo of 9.1

mm.422

after

His)

XXXI VFIG.

LIST OF ILLUSTRATIONS.PAGE

126. Transverse section of the medulla

127.

from an embryo of eight weeks. (McMurrich after His) 423 Transverse section of the spinal cord, from an embryo of (A) four and one-half weeks, and (B) of three months.

(McMurrich128.

after

His)

427

Mode

of origin of anteriornerves.

and

posterior roots of spinal

Diagrammatic.

(Brubaker and Edinger after

His)

428

ERRATA.Page 30.vesicles.

Paragraph two,

last line, last

word should be brain-

Page 57- Fig- 2 3- "Intraparietal sulcus," and wherever found should be written Interparietal sulcus.

Page

1 08.

Paragraph

four, fourth line, second

word

is

sulcus,

instead of "fissure."

Page 184.Page 264.spinal tract,"

Paragraph one,Fourthline,

last line

and

first

word

is

Alfred,

instead of "Arthur." the phrase "anterior ascending cerebelloit

and wherever

occurs, should read

Ascending an-

terior cerebello-spinal tract.

Page 265. Paragraph two, third line, the phrase "anterior descending cerebello-spinal tract," should stand Descending anterior cerebello-spinal tract: likewise, wherever the quoted phrase is found.Third line, last word is (Horsley). Paragraph three, last sentence, the phrase "fasciculus cerebello-spinalis," and wherever else it occurs should stand thus fasciculus cerebello-spinalis (posterior). Page 288. Paragraph three, fifth line, the substantive "cerebello-

Page 277. Page 286.

spinal fasciculus" should have "posterior" prefixed so as to read posterior cerebello-spinal fasciculus. This is a necessary variation

from the

BNA andLaststriae.

Page 291.the medullary

applies wherever the phrase is found. line, there should be added a fifth item, viz., (e)

ERRATA.

XXXV

Page 319. Page 35 1-

Fifth line,

common

sensory should be added under

intermediate nerve.

as

Paragraph three, third item, (3) should be omitted, no posterior root-fibers decussate. Intrinsic fibers only cross through the gray commissure (Mott and Russell).

Page 358.

To the last sentenceFourthline,

should be added:

to Sir Victor Horsley has to do with

and according locomotion (Brain, 1906).

Page 410.sulcus.

"callosal fissure" should be callosal

BRAIN AND SPINAL CORD.CHAPTERI.

THE MENINGES OF THE BRAIN.(Meninges Encephali.}invest the brain and spinal cord. They from without inward, the dura mater, the arachnoid, and Each membrane forms a protecting sheath for the pia mater.are,

Three membranes

the cerebral or spinal nerves piercing

it.

THE DURA MATER OF THE BRAIN.(Dura Mater Encephali.)Structure and Relations.Itis

a very dense and inelastic

membrane composedlined

of white fibrouscells,

and yellow

elastic tissueits

with

flat

endothelialit is

which constitute

internal

surface.

which

it

closely adherent to the cranial bones of forms the real periosteum; but it is attached chiefly at

In children

the foramina and along the sutures in adults. The dura of the brain is made up of two layers which are separable up to the

eighth or tenth year. teum of the cranial

The

external layer constitutes the endosItis

bones.

their nutrientit

membrane.

Through

the cranial foramina

and sutures

is

continuous with

In the adult the internal layer of the the external periosteum. dura separates from the outer layer only over the apex of thepetrous bone, to form Meckel's space for the semilunar ganglion (Gasseri); at the foramina, to form sheaths for the nerves; and,

along the sinuses, to form their internal boundary and to producethe great incomplete partitions, called processes, which project centrally into the great fissures of the brain.

Processes.of the

(Processus dura matris).

Fromoff.

the inner surface

dura the great processes are giveni

The

falx cerebri

2

THE MENINGES OF THE BRAIN.

and falx cerebelli hang vertically in the longitudinal fissure of the cerebrum and the posterior notch of the cerebellum; and,'into the transverse fissure of the cerebrum, extends horizontally the

tentorium

cerebelli.

The

falx cerebri (Figs,

i,

and

4)

is

attached

in front to the crista galli

and behind

to the internal occipital pro-

tuberance and superior surface of the tentorium; the falx cerebelli (Fig. i) continues from the inferior surface of the tentorium, along the occipital crest, to the posterior border of the foramen

magnum.(Fig. 2)is

The bony attachment

of

the

tentoriumlateral

cerebelli

to the internal protuberance

and the

arms of

the crucial ridge forward to the petrous bone; and, then, it is along the superior border of the petrous bone to the clinoid processes -of the sphenoid. Between its clinoid attachments there is

a deep bay, the incisura

tentorii,

which transmits the midbrain.

The diaphragma

sellae is

a small centrally perforated sheet of

dura which covers the hypophyseal fossa. Sinuses. (Sinus dura matrix}. Large venous passages lined with endothelial cells, and called sinuses, are situated betweenIn the convex and in the layers of the dura (Figs, i, 2, 3 and 4). the free border of the falx cerebri are, respectively, the superiorsagittal sinus(s.

sagittalis superior)

and the inferior sagittalsuperior(Fig.T)

sinus

(s.

sagittalis

inferior).

Theto the

extends

from the foramen caecum back

confluens sinuum (torcular

Having Herophili,) located at the internal occipital protuberance. run through the posterior two-thirds of the concave border ofthe falx cerebri, the inferior sagittal sinus joins the great cerebral vein at the margin of the tentorium and forms the straight sinus The latter runs through the middle of the tentorium (s. rectus).to the confluens(Fig.2).

The

occipital sinus

(s.

occipitalis)

traverses the falx cerebellito

from the foramen

magnum upward

the

same(s.

point.

In

the confluensrise

sinuum the transverse

sinuses

transversi)

arms

of the crucial ridge,

(Fig. 2). Grooving the horizontal each runs outward in the tentorium to

the base of the petrous bone, where it receives the superior petrosal sinus; it then turns downward through the sigmoid fossa, com-

municates with the occipital sinus and unites with the inferior Situated on either side petrosal sinus in the jugular foramen.

THE DURA MATER OF THE BRAIN.of the sella Turcicais

3

a continuation of the ophthalmic vein,

the large cavernous sinus (s. cavernosus] (Fig. 3), which receives at the sphenoidal fissure the sinus (s. ala parva], spheno-parietal the course of which is along the posterior border of the lesser

wing of the sphenoid bone.

At the posterior clinoid process the

Fig.

i.

Sagittal section of skull,

showing

tentorium cerebelli and sinuses.

falx cerebri, falx cerebelli, part of (After Morris's Anatomy.')

d. Great cerea. Falx cerebri. b. Superior sagittal sinus, c. Inferior sagittal sinus, bral vein. e. Straight sinus, f. Tentorium cerebelli. h. Superior g. Transverse sinus, sinus, i. Falx cerebelli. j. Seventh and eighth nerves, k. Ninth, tenth, and petrosal eleventh nerves. 1. Twelfth nerve, m. Second cervical nerve, n. Fourth nerve, o. Third nerve, p. Second nerve, q. Middle meningeal artery, r. Internal carotid artery, s. Vertebral artery, t. Fifth nerve, u. Sixth nerve, v. Inferior petrosal sinus, w. First cervical nerve, x. Ligamentum denticulatum.

cavernous sinus divides into the superior petrosal sinus (s. petrosus superior] and the inferior petrosal sinus (s. petrosus inferior}. The sinus intercavernosus anterior and sinus intercavernosusposterior extend across the

hypophyseal fossa, and join the two

cavernous sinuses together, and these four communicating sinuses

THE MENINGES OF THE BRAIN.constitute the circular sinus(s.

circular is) (Fig. 3).

From

the

bifurcation of the cavernous sinus^at the apex of the petrous bone, the petrosal sinuses run outward along the corresponding superior

and

inferior borders of that

boneJj^Thejsuperior petrosal sinus

Fig. 2.

Horizontal section of skull, showing tentorium cerebelli, tentorial notch and sinuses. (After Morris's Anatomy.)f.

b. Internal carotid artery, c. Optic tract, d. Third nerve, e. Basis Cerebral aqueduct (Sylvii). g. Quadrigeminal body. h. Falx cerebri. cerebelli. j. Straight sinus, k. Crista galli. 1. Optic nerve, m. Spheno-' parietal sinus, n. Middle cerebral artery, o. Anterior cerebral artery, p. Posterior communicating artery, q. Cavernous sinus, r. Superior cerebellar artery, s. Posterior cerebral artery, t. Superior petrosal sinus, u. Free border of tentorium bounding tentorial notch. v. Transverse sinus, w. Superior sagittal sinus. a.

Infundibulum.

pedunculi.i.

Tentorium

(Figs,

i

and

2)

empties into the transverse sinus at the base of

the petrous bone; the inferior petrosal sinus, in its course to the jugular foramen, is joined to its fellow, across the basilar processof the occipital bone,

by the basilar plexus

(p. basilaris]

and, in

THE DURA MATER OF THE BRAIN.

5

the jugular foramen, unites with the transverse sinus in forming the internal jugular vein. Arachnoid Granulations (Fig. 25). Along and within the

Fig.

3.

Sinuses in the base of the cranium, also meningeal arteries. (After Morris's Anatomy.)

a. Meningeal branch of anterior ethmoidal artery, b. Meningeal branch of posterior ethmoidal artery, c. Middle meningeal artery, d. Ophthalmic division of fifth nerve, e. Third nerve, f. Cavernous sinus, g. Fourth nerve, h. Auditory and facial nerves, i. Superior petrosal sinus, j. Inferior petrosal sinus, k. Petro-squamosal sinus. 1. Accessory nerve. m. Sigmoid part of transverse sinus, n. Posterior meningeal branch of vertebral artery. o. Left marginal sinus, p. Left transverse sinus, q. Superior sagittal sinus, r. Circular sinus, s. Carotid artery, t. Sixth nerve, u. Basilar artery, v. Basilar plexus of veins. w. Auditory artery, x. Vertebral artery, y. Glossopharyngeal and vagus nerves, z. Anterior spinal artery, aa. Hypoglossal nerve, bb. Accessory nerve, cc. Right marginal sinus, dd. Occipital sinus, ee. Right transverse sinus.

superior sagittal, the straight, the transverse, the petrosal and the cavernous sinuses are the granulationes arachnoideales (Pacchionian bodies). These granulations are enlarged villi of the

6

THE MENINGES OF THE BRAIN.(Fig. 4)

arachnoid

and seem

to

afford

an

outlet for the sub-

arachnoid fluid into the sinuses.

They

are said to

make

their

appearance about the tenth year and to be more numerous and

Some of them by absorption produce larger in the male sex. depressions in the cranial bones called joveola granulares.

The

arteries

which

supply the dura are

(i)

The

anterior

meningeal from the anterior ethmoidal branch of the ophthalmic. (2) The middle meningeals, viz., the great and the small middlemeningeal from the internal maxillary, the meningeal branch

Fig. 4.

Coronal section showing falx cerebri, superiorgranulations.

sagittal sinus

and arachnoid

(Gordinier after

Key and

Retzius.)

a.

d.

Dura mater,

Subarachnoid space, b. Superior sagittal sinus, c. Arachnoid granulations (Pacchioni). f. Anterior cerebral artery, e. Falx cerebri. g. Corpus callosum.

and of the internal carotid, and the meningeal branch of the ascending pharyngeal which enters the middle fossa of the cranium through the lacerate foramen. (3) Theof the lacrimal

posterior

meningeal

arteries,

which

rise

from the ascending

pharyngeal, the occipital and the vertebral and are distributed to the dura over the posterior cranial fossa.is

The great middle meningeal artery (arteria meningea media) much the largest and is most important (Fig. 5). It overliesLike the otherAscendarteriesit is

the motor and somaesthetic areas of the brain.

meningeal

usually accompanied by two veins.

THE DURA MATER OF THE BRAIN.ing from the foramen spinosum

7

it divides near the upper border two large branches, the anterior and posterior. The posterior runs horizontally backward just below the squamoparietal suture and then ascends over the posterior half of the

of the

squamosa

into

parietal

bone.

The

anterior

behind the coronal suture.Quain,at

branch runs upward a half-inch -It may be located, according tohalf,

one inch,

at

one inch and a

and

at

two inches

Fig. 5.

Median

section of skull showing middle meningeal artery. (After Morris's Anatomy.)

behind the zygomatic process of the frontal bone and above thezygomatic process of the temporal bone. The following nerves give branches to the dura:ophthalmic, semilunar ganglion, vagus of the cerebral group; and the sympathetic.lear,

Troch-

and hypoglossal The motor fibersAbsence ofof periosteal

supply the meningeal arteries. Six Points of Difference in the

Dura

of the Cord.

processes, of sinuses, of arachnoid granulations,

and

8function.is

THE MENINGES OF THE BRAIN.Itis

covered on both surfaces by endothelium andtissue, fat

separated from the vertebrae by areolar

and the plexus

of internal vertebral veins.

THE ARACHNOID OF THE BRAIN.(Arachnoidea Encephali.)

In structure

it is

a delicate, fibrous, web-like

membrane covered

externally with endothelium. Internally it is joined to the pia mater by innumerable fibrous trabeculae, the subarachnoid tissue(Fig. 4).

The

trabeculae are ensheathed

and

all

subarachnoid

spaces lined with a single layer of endothelial cells, hence both surfaces are formed of endothelium. Conical elevations offibrousvilli

tissue with their investing endothelium seen on the outer surface.*

constitute

the

Relations.

The arachnoid

follows the inner surface of the

dura andit.

is

prolonged, as a sheath,

upon the nerves which

pierce

does not dip into the sulci of the cerebrum (Fig. 6); but into the lateral fissure and the longitudinal fissure, and does only not reach to the bottom of the latter. From the pia it is sepaIt

rated by the

subarachnoid spaces (cava subarachnoidealia}. Thecisterna

anterior subarachnoid space (Fig. 6) includes the cistema pontis,

cisterna

interpeduncularis,It is

chiasmatis

and

cistema

located in front of the medulla, pons and mid-brain and between the temporal lobes of the cerebrum.fossae lateralis cerebri.

The

posterior subarachnoid space (Fig. 6)It

is

located behind the

medulla and cerebellum.

embraces the cisterna cerebello-

medullaris, a space between the medulla and cerebellum, and the cisterna venae cerebri magnae, situated along the straight sinus and the great cerebral vein. These two, the anterior and posterior,

the subarachnoid fluid.

are the largest subarachnoid spaces and they contain much of But in the cerebral sulci and fissures

there are streams of this fluid which constitute the subarachnoidrivulets.

The

anterior

subarachnoidthis

space

has

slit-like

com-

* Some authors consider

membrane, as

just described above,

merely as a visceral layer of the arachnoid, and regard the endothelial lining of the dura mater as its parietal layer. According to such,therefore, the subdural space

becomes the arachnoid space.

THE

PIA

MATER OF THE BRAIX.

munications with the inferior horn of the lateral ventricle; theposterior space communicates with the fourth ventricle (Fig. 8) through the median aperture (apertura mediana ventriculi quarti,

Magendi} and the lateral apertures (apertura quarti, Key and Retzii).

laterales ventriculi

The

to the pia mater.

vessels seen for a short distance in the arachnoid belong Its nerves are doubtful. Perhaps branches

of the mandibular, of the facialPia mater

and of the accessory supplySubarachnoid space

it.

Arachnoid

Third ventricle

Fourthventricle

InfundibulumCisterna interpeduncularis

Cisterna cerebello-medullaris

Median aperture (Magendi)

Cisterna pontis

Fig. 6.

Diagram

of pia and arachnoid, showing subarachnoid spaces. (After Morris's Anatomy.)

In the arachnoid and these, in great

tumit

fewer trabeculae join it to the pia; are collected to form a fenestrated seppart, hi the posterior median line (Fig. 97, A). The externalof the cord

spinal veins are covered

by the

spinal arachnoid, they

lie

between

and the

pia.

THE PIA MATER OF THE BRAIN.(Pia Mater Encephali.)

Structure and Relations.

It

is

a vascular

membrane com-

posed of a close network of veins and arteries held together by

10

THE MENINGES OF THE BRAIN.

fibro- elastic areolar tissue (Fig. 9).

outer surfacetrabeculae.

The endothelium covering its continuous with that ensheathing the subarachnoid The pia closely follows the brain surface (Fig. 6).is

Internally,

it

transmit

blood-vessels;

sends supporting trabeculae into the brain, which and externally it forms an investing

sheath for each cerebral nerve. Folds.(i)

Two

The chorioid

important processes are formed by the pia mater tela of the third ventricle (tela chorioidea:

ventriculi tertii) is

pushed forward into the anterior part of the transverse fissure of the cerebrum between the fornix and theinterbrain (Fig. 6). Hence the old name, velum interpositum. It is triangular in shape, with apex directed forward (Fig. 7). Each lateral border is tucked into the chorioidal fissure of the cerebral

hemisphere and enters into the

floor of the lateral ventricle, while

the median part of the fold is in the roof of the third ventricle. Between the two layers of this chorioid tela is some areolar tissue

through which run backward the two internal cerebral veins and unite near the base of the tela to form the great cerebral vein.

The

chorioid plexuses of the lateral

and the third

ventricles oc-

cupy, respectively, the lateral borders and the median area of this chorioid tela. second fold of pia mater is tucked .into (2)

A

the transverse fissure of the cerebellum, dorsal to the medulla

oblongata and ventral to the posterior median part of the cerebellum (Fig. 6). It is called the chorioid tela of the fourthventricle(tela

layer enters into the roofventricle.

chorioidea ventriculi quarti) because its inferior and contains the chorioid plexus of that

This lower layer invests the posterior surface of the

medulla and the roof -epithelium of the fourth ventricle (Fig. 8). It is pierced by three foramina which are situated as follows:

One

over each lateral angle of the fourth ventricle, the lateral The apertures (Key and Retzii), and one over its inferior angle.latter is the largest

and is called the median aperture (Magendi). Those three foramina establish communication between the posterior subarachnoid space and the fourth ventricle.

The11

and

arteries of the pia mater supply the brain (Figs. 9,- 10, 12). They are the anterior, middle and posterior cerebrals;

the anterior and posterior chorioidals; and the anterior and pos-

THE

PI A

MATER OF THE BRAIN.

II

Fig.

7.

Horizontal section of cerebrum.tela of third ventricle,

Fornix turned back, showing chorioid(Original.)

and

internal cerebral veins.

THE

PIA

MATER OF THE BRAIN.and the superiorcerebellar with

13

terior inferior cerebellar

many

branches.

The veinsthe internal

are

more numerous than the

arteries in the pia:

and great cerebral veins, the veins of the chorioid plexuses of the lateral, third and fourth ventricles and the basilar vein; the cerebral veins, superior, medial and inferior; and thesuperior and inferior cerebellar veins. the sinuses (see page 2).All of

them empty

into

Inferior quadrigeminal colliculus

FrenulumLateral

veli

Fourth nervefillet

Superior medullary

velum

Fourthventricle

Restiform bodyTaeniaEpithelial roof of fourth ventricle Cuneate tubercle

Inferior medullary

velumChorioid plexus

Clava

Median aperture(Magendi)

Tuberculum

cinereurr*

Obex

Fig. 8.

Roof and

lateral walls of fourth ventricle,

and

its

chorioid plexuses.

(After Morris's Anatomy,)

Seven cerebral nerves

3d, 5th, 6th, yth, Qth, icth

and nth

and the sympathetic supply the pia mater and its blood-vessels. The pia mater of the spinal cord has two layers, the outer of which is the more vascular and contains the spinal arteries andthe tributaries of the external spinal veins. It forms three processes, namely, the anterior septum, which occupies the anterior median fissure, and the ligamentum denticulatum of each side.

14

THE MENINGE3 OF THE BRAIN.

THE BLOOD SUPPLY OF THE BRAIN.furnished with blood by the internal carotid and The internal carotid artery (a. vertebral arteries (Fig. 9). carotis interna] gives origin to the anterior and the middle cere-

The

brain

is

bral, 'the anterior chorioidal

the vertebral arteryposterior spinalunites withits

(a,

and the posterior communicating; vertebralis) gives off the anterior andinferior cerebellar

and the posterior

and thenand forms

fellow at the inferior border of the pons

the basilar artery.

The

basilar artery

(a. basilaris]

runs upward

the length of the pons.

and terminates

in the

two posterior cerebral

arteries and, furthermore, gives off the following collateral branches,

the anterior inferior cerebellar, the pontal, the internal audiCertain of these arteries form tory and the superior cerebellar. a wonderful circular anastomosis at the base of the brain, calledviz.,

the arterial circle and the distribution of that circle

is

to the cerecere-

brum

(Figs. 9

and

10); while theis

rhombencephalon (pons,

bellum and medulla) above enumerated.

supplied by the remainder of the arteries It is therefore convenient to describe the

circulation of the brain

under two heads:

of the cerebrum, and (B)

The

(A) The circulation circulation of the rhomben-

cephalon.A.

THE CEREBRAL CIRCULATION, ARTERIES.(Circulus arteriosis, Willisi).

Theies

Arterial Circle.

The

arter-

which supply the cerebrum freely communicate in the arterial circle, which is really a heptagon extending from a point in thelongitudinal fissure anterior to the optic chiasma, back to the pons It is about an inch and a half long, and from a half (Fig. 9).to

one inch in transverse diameter.

In front are the anterior

cerebral arteries converging forward from the internal carotids and, through the anterior communicating artery (a. communicansanterior], uniting just as they enter the longitudinal fissure of the

cerebrum.

These

vessels

form three

sides of the

heptagon and

the front of the circle.

On

either side, the posterior

communic-

ating artery (a. posterior] carotid with the posterior cerebral artery, forms the lateral bound-

communicans

which connects the internal

THE CEREBRAL CIRCULATION, ARTERIES.ary of thecirclecircle.

15

The

posterior

cerebral

arteries

bound

the

behind, and so complete it (Fig. 10). The large distal branches of the arteries which are connected with the arterialcircle are distributed

chiefly to the cortex

hemispheres;

while

the

and medulla of the branches supply the small proximal

Fig. 9.

Arterial circle

and its branches on the base of the brain. (After Morris's Anatomy.}d. g.

terior inferior cerebellar artery, h. Vertebral artery, i. Posterior inferior cerebellar artery. Anterior communicating artery, k. Antero-lateral ganglionic. 1. Anterior chorioid. j. m. Posterior communicating artery, n. Posterior chorioid. o. Basilar artery, p. Hemisphere of cerebellum cut away. q. Anterior spinal artery.

c. Internal carotid artery, b. Middle cerebral artery, a. Anterior cerebral artery, terp-median ganglionic. e. Posterior cerebral artery, f. Superior cerebellar artery,

Pos-

An-

ganglia and the inter-brain. The former belong to the cortical system (Ai), the latter to the ganglionic system (A2). Al. The Cortical System of Arteries. The cortical arterial

system comprises the distal portions of the anterior, middle and The branches of posterior cerebral and the chorioidal arteries.

16

THE MENINGES OF THE BRAIN.

these great vessels pierce the hemispheres perpendicularly to the surface. They are distributed, the short, to the cortex, and thelong, to the

medulla of the hemispheres.

To

a limited extent

they anastomose with one another, but they do not communicate

with the ganglionic system. The anterior cerebral artery

(a. cerebri

anterior, Figs. 9

and

12), a branch of the internal carotid, runs forward and toward the median line above the optic nerve and enters the longitudinalfissure;it

is

here joined to

anterior communicating.

mate by a very short artery, the Winding around the genu of the corpusits

callosum,

it

the occipito-parietal sulcus.

runs back on the medial surface of the hemisphere to It gives origin to the antero-median

ganglionic arteries, and to four groups pf cortical branches:(1)

The

internal orbital artery (Figs. 9

and

the medial orbital gyrus, the gyrus rectus, the olfactory bulb, tract, medial and intermediate

which supplies the optic chiasma and10)striae,

triangle,

and parolfactory area. (2) The anterior internal frontal (Fig. 12) which enters the anterior parts of the gyrus cinguli and superior frontal gyrus on the medial surface and of the superior and middle frontal gyri on the convex surface. (3) The middle internal frontalbranches, which are distributed to the middle part of the gyrus cinguli, to the paracentral lobule and to the upper portions of the

superior frontal and the anterior

and

posterior central gyri.

(4)

The

posterior internal frontal branches,

which run back

to the

occipito-parietal sulcus.

They supply nearly the whole corpus the posterior half of the gyrus cinguli, a part of the callosum, paracentral lobule, the praecuneus, and the superior parietal

lobule.

The middleof theit

cerebral artery

(a. cerebri

media, Figs. 10 and

n)

crosses the anterior perforated spot

and runs in the

lateral fissure

cerebrum

to the posterior sulcus circularis (Reili)

where

breaks up into several parieto-temporal branches. It gives origin to the antero-lateral ganglionic arteries, and to four cortical

branches:

(i)

The

lateral

orbital

branches are distributed to

the anterior and posterior orbital and the inferior frontal gyri. (2) The ascending frontal, two branches, which follow the precentral

and central

sulci,

supply the anterior central gyrus and

THE CEREBRAL CIRCULATION, ARTERIES.

17

the posterior fourth of the middle frontal gyrus. (3) The ascending parietal, whose course is along the interparietal sulcus, furnishesparts

bloodof

to

the posterior central gyrus and the adjacent

and inferior parietal lobules. (4) The arteries, which comprise two polar branches to the temporal lobe and a large posterior branch. The latter runs in the posterior ramus of the lateral cerebral fissure to its upturned posterior end and there bifurcates into a parietal and a temporal branch, which just pass the anterior limit of the occipthe superior

par ieto- temporal

ital lobe.is

The

entire distribution of the parieto-temporal arteries

to the temporal pole and to the superior, middle and part of the inferior temporal gyri; to the major parts of the supramarginal, angular and post-parietal gyri, and to a very small portion of the superior

and

lateral occipital gyri.(a.

The posterior cerebral arteryminal branch of thearterial circle

cerebri

posterior},

a

ter-

basilar, lies in the posterior

boundary

of the

joined to the internal carotid by the posterior communicating artery (Figs. 10 and 12). It winds backward between the midb^ain and gyrus hippocampi to the tentorialis

and

surface of the cerebral hemisphere where, just beyond the splenium of the corpus callosum, it terminates in the calcarine and occipito-

From the posterior cerebral arteries originate parietal branches. the postero-median and the postero-lateral ganglionic, and two or more posterior chorioidal arteries and three corticalbranches: (i) The temporal branches, often an anterior, middle and posterior temporal, which supply the hippocampal and thefusiform gyri and a part of the lingual and of the inferior temporal gyrus. (2) The calcarine artery, which runs along the fissure of the same name and supplies the cuneate and lingual gyri; also the pole and the lateral

and superior

gyri of the occipital lobe.

(3)

occipito- parietal artery, a single branch, which runs along the sulcus occipito-parietalis over the supero-medial border to

The

the convex surface of the cerebral hemisphere and is distributed to the cuneus, the praecuneus and the superior occipital gyrus.

The

posterior

chorioidal

arteries (arteries chorioidea posteof

rior es, Figs. 7, 9

and

10) two or more in number are branches

18

THE MENINGES OF THE BRAIN.

the posterior cerebral which run forward in the transverse and chorioidal fissures of the cerebrum to the chorioid plexuses of the lateral and third ventricles (Fig. 7).

The

anterior chorioidal arteries

(a.

chorioidea anterior] rises

from the internal carotid artery just proximal to its anterior and middle cerebral branches, and runs backward and outward alongthe optic tract to the anterior inferior end of the chorioidal fissure, which it enters (Fig. 10). It terminates in the chorioid plexus of the inferior horn of the lateral ventricle, and gives collateral

branches to the optic

tract,

dentata, the hippocampus, the crus of the fornix part of the internal capsule.

the gyrus hippocampi, the fascia and the posterior

from thecircle

A2. The Ganglionic System of Arteries. Small arteries arterial circle and from the cerebral arteries near theconstitutethis

their distribution

system (Fig. 10). The arteries pass to without communicating with one another or

They are the end-arteries of Cohnheim. and ganglionic systems, there is an area poorly supplied with blood. That is the area of cerebral softening in old age. The ganglionic system of arteries is made up of six of small vessels: The antero-median, the right and left groups antero-lateral, the postero-median and the right and left posterowith the cortical arteries.cortical

Between the

lateral.

The antero-median ganglionic

arteries rise from the anterior

cerebrals in front of the optic chiasma (Fig. 10). They supply the chiasma, the lamina terminalis, the rostrum of the corpus

callosum, the septum pellucidum and the head of the caudate nucleus.

Thearterial

either side,

antero-lateral ganglionic arteries take their origin, on from the middle cerebral artery, a little outside the

circle (Fig. 10). They pierce the anterior perforated substance and are distributed to the striated body, internal capsule and thalamus. The largest one of this group is the lenticulostriate artery.It suppliesits

On account

of

the greater part of the corpus striatum. frequent rupture, it is called the artery of cerebral

hemorrhage (Charcot).

Postero-median Ganglionic Arteries.

These are branches

THE CEREBRAL CIRCULATION, ARTERIES.

Fig. 10.

Arterial circle

and its branches on the base of the cerebrum. (Gordinier after Duret.)

On the left side of the brain the temporal lobe is cut away so as to open the inferior and posterior horns of the lateral ventricle. The mid-brain is divided close above the pons and the posterior cerebral arteries are cut at their origin from the basilar. Ganglionic arteries: am. Antero-median group arising from the anterior cerebral, al. Antero-lateral group, from the middle cerebral, pm, pi (on the optic thalamus). Posteromedian and postero-lateral groups, from the posterior cerebral. Chorioidal arteries: a ch. Anterior, from the internal carotid, p ch (on the splenium). Posterior, from the posterior cerebral. Cortical arteries: I, I. Inferior internal frontal, from the anterior cerebral. 2. Inferior external frontal. 3. Ascending frontal. 4. Ascending parietal, and 5, temporo-parietal from the middle cerebral. 6. Anterior temporal, 7, posterior temporal, and 8, occipital, from the posterior cerebral.

VEINS OF THE CEREBRUM.of the posterior cerebral

21arteries

and posterior communicating

They supply the interpcduncular structures, (Figs. 9 and 10). the peduncles and, after piercing the posterior perforated substance, the walls of the third ventricle and the medial parts ofthe thalami.

Postero-lateral Ganglionic Arteries.side,

They

rise,

on

either

from the posterior cerebral artery after it has wound around the base of the peduncle (Fig. 10). They are distributed to the of the thalamus; the geniculate, quadrigeminal and posterior partpineal bodies; the quadrigeminal brachia and the pedunculus The superior cerebellar arteries send several branches cerebri.to the

dorsum

of the mid-brain,

and complete the

arterial

supply

of the cerebrum.

VEINS OF THE CEREBRUM.The Internal Veins of the Cerebrum. The veins of the cerebrum (vents cerebri) are classed as internal and external. Thetrunks of the internal veins are located largely in the chorioid tela of the third ventricle, near the apex of which the internalcerebral veinis

formed: while at the base ofits

this chorioid tela

the internal cerebral vein unites withgreat cerebral vein.

mate

in forming the

The

internal cerebral vein

(v. cerebri

interna)

is

formed by

the union of the chorioidal, the terminal and the vein of the septum pellucidum. It runs backward between the layers of thechorioid tela of the third ventricle(Fig.7),

receiving several

small collaterals from the

tela,

from the pineal and quadrigeminal;

bodies and the corpus callosum and, finally, it receives the basilar vein from the inferior surface of the cerebral hemisphere. Underthe splenium of the corpus callosum it joins the internal cerebral vein of the opposite side and forms the great cerebral vein.

The great cerebral veinthick,

(v. cerebri

median trunk, a half-inch long

magna, Galeni) is a short, At the posterior (Fig. i).

border of the tentorial notchsinus

it is joined by the inferior sagittal and then continued as the sinus rectus. This short vein receives collateral tributaries from the gyrus cinguli, from the

22

THE MENINGES OF THE BRAIN.

medial and tentorial surfaces of the occipital lobe and from the superior surface of the cerebellum (Cunningham).

Small nameless internal veins issue fromsurface of the cerebrum

all

parts of the exterior

and form the external veins. The External Veins of the Cerebrum. The external cerebral veins (vena cerebri externa) are numerous and of large size. Theyramify in the pia mater and in the subarachnoid space. They empty into the dural sinuses, as a rule, against the current in thesinuses,

and

they

form

two principal groups:

The

superior

Fig.

1 1

.

Middle cerebral artery and branches. (Gordinier after Quain and Charcot.)

Antero-lateral group of ganglionic arteries. I. Inferior external frontal artery. 2. Ascending frontal artery. 4. Parieto-temporal artery. 3. Ascending parietal artery.

CENT.

cerebral

and the

inferior cerebral,

and a very small group, on

the

medial

cerebral surface, called the medial cerebral veins.

The superior cerebral veins (vena cerebri superiores), twelve or more in number, carry away the blood from the superior surface of the hemisphere. They run obliquely upward and forwardinto the superior sagittal sinus.

Just before emptying into the

sinus they receive most of the medial veins.

The Medial Cerebral Veins.

(Vena

cerebri mediales}.

They

drain the marginal part of the medial surface of the hemisphere.

VEINS OF THE CEREBRUM.

23into the superior

The

veins of this group which do not

empty

cerebral veins unite

and form the

inferior sagittal sinus,

and the

anterior cerebral vein which drains

much

of the medial surface.

inferior cerebral veins (vena cerebri inferiores) drain the base of the cerebrum and the lower border of its convex surface.

The

the tentorial surface of the hemisphere, from three to five of these veins empty into the transverse and superior petrosal sinuses. Those from the temporal and frontal lobes empty into

On

the

spheno-parietal sinus and cavernous sinus, excepting the small anterior cerebral vein and the deep middle cerebral vein,

which unite with thevein.

inferior striate veins in

forming the basilar

accompanies the artery of the drains the gyrus cinguli and corpus callosum, chiefly; and, in the fossa lateralis cerebri, unites with vessels that descend from the corpus striatum, the inferior striate veins, and

The

anterior cerebral veinIt

same name.

with the deep middle cerebral vein. The deep vena cerebri media drains the insula and the opercula, in part, and deep in the fissure runs medianward to the fossa lateralis cerebri and helps to form The basilar vein (v. basilaris), is formed at the the basilar.anterior perforated spot by the deep middle cerebral, the inferior striate and the anterior cerebral veins. Running backward itreceives

additional blood from the interpeduncular structures,

the hippocampal gyrus and the inferior horn of the lateral vent