blood supply

1. ANATOMY OF BRAINANATOMY OF BRAIN

2. BRAINSTEMBRAINSTEM  HeartHeart
rate and breathingrate and breathing
CEREBELLUMCEREBELLUM
 CoordinationCoordination
and balanceand balance
Parts of the BrainParts of the Brain
amygdalaamygdala
pituitarypituitary
hippocampushippocampus
THALAMUSTHALAMUS
 RelaysRelays
messagesmessages

3. The BrainThe Brain
• BrainstemBrainstem
–responsible forresponsible for
automatic survivalautomatic survival
functionsfunctions
• MedullaMedulla
–controls heartbeatcontrols heartbeat
and breathingand breathing

4. Reticular FormationReticular Formation
•Widespread connectionsWidespread connections
•Arousal of the brain asArousal of the brain as
a wholea whole
•Reticular activatingReticular activating
system (RAS)system (RAS)
•MaintainsMaintains
consciousness andconsciousness and
alertnessalertness
•Functions in sleep andFunctions in sleep and
arousal from sleeparousal from sleep

5. The CerebellumThe Cerebellum
–helps coordinatehelps coordinate
voluntaryvoluntary
movement andmovement and
balancebalance

6. The Limbic SystemThe Limbic System
• Hypothalamus, pituitary,Hypothalamus, pituitary,
amygdala, and hippocampusamygdala, and hippocampus
all deal with basic drives,all deal with basic drives,
emotions, and memoryemotions, and memory
• HippocampusHippocampus  MemoryMemory
processingprocessing
• AmygdalaAmygdala  AggressionAggression
(fight) and fear (flight)(fight) and fear (flight)
• HypothalamusHypothalamus  Hunger,Hunger,
thirst, body temperature,thirst, body temperature,
pleasure; regulates pituitarypleasure; regulates pituitary
gland (hormones)gland (hormones)
• ``

7. The Limbic SystemThe Limbic System
 HypothalamusHypothalamus
 neural structure lyingneural structure lying
below (below (hypohypo) the) the
thalamus; directs severalthalamus; directs several
maintenance activitiesmaintenance activities
 eatingeating
 drinkingdrinking
 body temperaturebody temperature
 helps govern thehelps govern the
endocrine system via theendocrine system via the
pituitary glandpituitary gland
 linked to emotionlinked to emotion

8. The Limbic SystemThe Limbic System
• AmygdalaAmygdala
–two almond-two almond-
shaped neuralshaped neural
clusters that areclusters that are
components ofcomponents of
the limbic systemthe limbic system
and are linked toand are linked to
emotion and fearemotion and fear

9. He killed his wife andHe killed his wife and
mother before going to themother before going to the
top of the university towertop of the university tower
and opened fire on personsand opened fire on persons
crossing the campus andcrossing the campus and
on nearby streets. Heon nearby streets. He
ended up killing 16 peopleended up killing 16 people
and wounded 31, beforeand wounded 31, before
being killed by policebeing killed by police
officers. The shootingofficers. The shooting
spree lasted 96 minutes.spree lasted 96 minutes.
Post-mortem revealed aPost-mortem revealed a
brain tumor near hisbrain tumor near his
amygdala.amygdala.

10. The BrainThe Brain
• ThalamusThalamus
– the brain’s sensorythe brain’s sensory
switchboard, locatedswitchboard, located
on top of theon top of the
brainstembrainstem
– it directs messages toit directs messages to
the sensory receivingthe sensory receiving
areas in the cortexareas in the cortex
and transmits repliesand transmits replies
to the cerebellum andto the cerebellum and
medullamedulla

11. The Cerebral CortexThe Cerebral Cortex
• Cerebral CortexCerebral Cortex
–the body’sthe body’s
ultimate controlultimate control
and informationand information
processingprocessing
centercenter

12. The lobes of the cerebral hemispheresThe lobes of the cerebral hemispheres

13. The lobes of the cerebral hemispheresThe lobes of the cerebral hemispheres
Planning, decisionPlanning, decision
making speechmaking speech
SensorySensory
AuditoryAuditory
VisionVision

14. The Cerebral CortexThe Cerebral Cortex
• Frontal LobesFrontal Lobes
– involved in speaking and muscle movementsinvolved in speaking and muscle movements
and in making plans and judgmentsand in making plans and judgments
– the “executive”the “executive”
• Parietal LobesParietal Lobes
– include the sensory cortexinclude the sensory cortex
• Occipital LobesOccipital Lobes
– include the visual areas, which receive visualinclude the visual areas, which receive visual
information from the opposite visual fieldinformation from the opposite visual field
• Temporal LobesTemporal Lobes
– include the auditory areas, each of whichinclude the auditory areas, each of which
receives auditory information primarily from thereceives auditory information primarily from the
opposite earopposite ear

15. The Cerebral CortexThe Cerebral Cortex
• FrontalFrontal (Forehead to top)(Forehead to top)  Motor CortexMotor Cortex
• ParietalParietal (Top to rear)(Top to rear)  Sensory CortexSensory Cortex
• OccipitalOccipital (Back)(Back)  Visual CortexVisual Cortex
• TemporalTemporal (Above ears)(Above ears)  Auditory CortexAuditory Cortex

16. Motor/Sensory CortexMotor/Sensory Cortex
• ContralateralContralateral
• HomunculusHomunculus
• UnequalUnequal
representationrepresentation

18. Sensory Areas – Sensory HomunculusSensory Areas – Sensory Homunculus
Figure 13.10Figure 13.10

19. BLOOD SUPPLY OFBLOOD SUPPLY OF
BRAINBRAIN

20. BLOOD SUPPLY OF BRAINBLOOD SUPPLY OF BRAIN

21. ARTERIAL SUPPLY OF BRAINARTERIAL SUPPLY OF BRAIN
COMMON CAROTID ARTERYCOMMON CAROTID ARTERY
• 70% blood is delivered to ICA
• Carotid bifurcation is a physiological
stenosis.
• CCA divides lateral to upper border of
thyriod cartilage: C3-4 intervertebral
disc.
• ECA arises anterior and medial to
ICA(95%)

22. CAROTID VESSELSCAROTID VESSELS

23. ARTERIAL SUPPLY OF BRAINARTERIAL SUPPLY OF BRAIN

24. INTERNAL CAROTID ARTERYINTERNAL CAROTID ARTERY
1.1. CERVICAL SEGMENTCERVICAL SEGMENT
2.2. PETROUS SEGMENTPETROUS SEGMENT
3.3. CAVERNOUS SEGMENTCAVERNOUS SEGMENT
4.4. SUPRACLINOID SEGMENTSUPRACLINOID SEGMENT

25. SUPRACLINOID SEGMENTSUPRACLINOID SEGMENT::
– Ascends posterior + lateral b/w
oculomotor and optic nerv.
– BRANCHES:
1. OPHTHALMIC A.
2. SUPERIOR HYPOPHYSEAL A. (not routinely
visualized)
3. PCOM
4. ANTERIOR CHOROIDAL A.
5. MCA
6. ACA

26. • CAROTID SIPHON: (3CAROTID SIPHON: (3rdrd
+ 4+ 4thth
part of ICA)part of ICA)
– FLOW DIRECTION: C4---C1
a) C4 SEGMENT= Before origin of
ophthalmic a.
b) C3 SEGMENT= Genu of ICA.
c) C2 SEGMENT= Supraclinoid segment
after origin of ophthalmic a.
d) C1 SEGMENT= Terminal segment of
ICA b/w pCom + ACA.

27. CAROTID SIPHONCAROTID SIPHON

28. ANTERIOR CEREBRAL ARTERYANTERIOR CEREBRAL ARTERY
1.1. A1 SEGMENT= HORIZONTALA1 SEGMENT= HORIZONTAL
PORTIONPORTION b/w origin and aCom.b/w origin and aCom.
• Inferior branches to optic nerve and chiasmaInferior branches to optic nerve and chiasma
• Superior branches to ant hypothalamus,Superior branches to ant hypothalamus,
septum pellucidum, ant commisure, fornix,septum pellucidum, ant commisure, fornix,
columns,columns, medial lenticulostriate artery tomedial lenticulostriate artery to
anteroinferior portion of corpus striatum.anteroinferior portion of corpus striatum.
1.1. A2 SEGMENT= INTERHEMISPHERICA2 SEGMENT= INTERHEMISPHERIC
PORTIONPORTION after the origin of aCom.after the origin of aCom.

29. • BRANCHES:BRANCHES:
1.1. Medial orbitofrontal artery.Medial orbitofrontal artery.
2.2. Frontopolar artery.Frontopolar artery.
3.3. Callosomarginal artery.Callosomarginal artery.
4.4. Pericallosal artery.Pericallosal artery.
• SUPPLY:SUPPLY: anterior 2/3 of medial cerebral
surface and 1cm of superomedial brain over
convexity.

32. MIDDLE CEREBRAL ARTERYMIDDLE CEREBRAL ARTERY
• LLargest branch of ICA, arises lat to optic
chiasma, passes horizontal and lateral direction
to enter in sylvian fissure and divides into 2/3/4
branches
• SUPPLY:SUPPLY:
– Lateral cerebrumLateral cerebrum
– InsulaInsula
– Anterior and Lateral temporal lobesAnterior and Lateral temporal lobes
• M1 SEGMENT:M1 SEGMENT:
– Origin to MCA bifurcationOrigin to MCA bifurcation
– Lateral lenticulostriateLateral lenticulostriate
• M2 SEGMENT:M2 SEGMENT:
– Insular branchesInsular branches
• M3 SEGMENT:M3 SEGMENT:
– MCA branches beyond sylvian fissure

33. INTERNAL CAROTID ARTERYINTERNAL CAROTID ARTERY

34. INTERNAL CAROTID ARTERYINTERNAL CAROTID ARTERY

37. VERTEBRAL ARTERYVERTEBRAL ARTERY
• 11stst
branch of subclavian(95%)branch of subclavian(95%)
• Left vertebral arises directly from aorticLeft vertebral arises directly from aortic
arch in 5%.arch in 5%.
• Left artery is dominant in 50%, in 25%Left artery is dominant in 50%, in 25%
co dominant, in 25% right is dominant.co dominant, in 25% right is dominant.

38. VERTEBRAL ARTERYVERTEBRAL ARTERY
A.A. PREVERTEBRAL SEGMENT:PREVERTEBRAL SEGMENT: EntersEnters
transverse foramina at C6, only musculartransverse foramina at C6, only muscular
branches.branches.
B.B. CERVICAL SEGMENT: AnteriorCERVICAL SEGMENT: Anterior
meningeal artery.meningeal artery.
C.C. ATLANTIC SEGMENT:ATLANTIC SEGMENT: exits throughexits through
transverse foramina of atlas till ittransverse foramina of atlas till it
peierces dura to enter cranial cavity.peierces dura to enter cranial cavity.
Branch: Post. Meningeal.Branch: Post. Meningeal.
D.D. INTRACRANIAL SEGMENT:INTRACRANIAL SEGMENT:

39. INTRACRANIAL SEGMENTINTRACRANIAL SEGMENT
• BRANCHES:BRANCHES:
1.1. ANTERIOR + POSTERIOR SPINAL A.ANTERIOR + POSTERIOR SPINAL A.
2.2. PICAPICA
 BASILAR ARTERY BRANCHES:BASILAR ARTERY BRANCHES:
1.1. AICAAICA
2.2. INTERNAL AUDITORY A.INTERNAL AUDITORY A.
3.3. SUPERIOR CEREBELLAR A.SUPERIOR CEREBELLAR A.
4.4. POSTERIOR CEREBRAL A.POSTERIOR CEREBRAL A.
5.5. MEDULLARY AND PONTINE PERFORATINGMEDULLARY AND PONTINE PERFORATING
ARTERIESARTERIES

41. POSTERIOR CEREBRAL ARTERYPOSTERIOR CEREBRAL ARTERY
• P1 SEGMENT:P1 SEGMENT:
– Origin to PCOM.Origin to PCOM.
– Posterior thalamoperforatorsPosterior thalamoperforators
• P2 SEGMENT:P2 SEGMENT:
– Distal to PCOMDistal to PCOM
– ThalamogeniculateThalamogeniculate
– Posterior choroidal arteries.Posterior choroidal arteries.
• TERMINAL CORTICAL BRANCHES.TERMINAL CORTICAL BRANCHES.

44. ARTERIAL ANASTOMOSES OFARTERIAL ANASTOMOSES OF
BRAINBRAIN
A.A. AT BASE OF BRAIN:AT BASE OF BRAIN:
I.I. CIRCLE OF WILLISCIRCLE OF WILLIS
II.II. DEVELOPMENTAL ANOMALIES: (3DEVELOPMENTAL ANOMALIES: (3
transient carotid-basilar anastomosestransient carotid-basilar anastomoses
appear in fetal life)appear in fetal life)
• Primitive hypoglossal arteryPrimitive hypoglossal artery
• Primitive acoustic arteryPrimitive acoustic artery
• Persistent primitive trigeminal arteryPersistent primitive trigeminal artery

45. CIRCLE OF WILLISCIRCLE OF WILLIS
• Complete in 25%,Complete in 25%,
incomplete in 75%.incomplete in 75%.
• Made byMade by
– Supraclinoid ICAsSupraclinoid ICAs
– A1 segment ofA1 segment of
ACAACA
– ACOMsACOMs
– PCOMsPCOMs
– P1 segment ofP1 segment of
PCAsPCAs

48. ANTERIOR CEREBRAL ARTERYANTERIOR CEREBRAL ARTERY

49. MIDDLE CEREBRAL ARTERYMIDDLE CEREBRAL ARTERY

50. POSTERIOR CEREBRAL ARTERYPOSTERIOR CEREBRAL ARTERY

53. EXTERNAL CEREBRAL VEINS:EXTERNAL CEREBRAL VEINS:
1.Superior cerebral veins.1.Superior cerebral veins.
2.Superficial middle cerebral veins.2.Superficial middle cerebral veins.
3.Deep middle crebral veins.3.Deep middle crebral veins.
4.Inferior cerebral veins.4.Inferior cerebral veins.
5.Anterior cerebral veins.5.Anterior cerebral veins.
INTERNAL CEREBRAL VEINS:INTERNAL CEREBRAL VEINS:
There is one vein on each side formed by union ofThere is one vein on each side formed by union of
lenticulostraite and choroidal veinslenticulostraite and choroidal veins..
TERMINAL VEINS:TERMINAL VEINS:
1.Great cerebral vein.1.Great cerebral vein.
2.Basal vein.2.Basal vein.
CEREBRAL VEINSCEREBRAL VEINS

56. THANK YOUTHANK YOU