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My Personal Presentation . Covers both Arterial and venous supply of brain .
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BRAIN :VASCULAR ANATOMY
DR ARIF KHAN S
INTRODUCTION
About 18% of the total blood volume in the body circulates in the brain, which accounts for about 2% of the body weight.
loss of consciousness occurs in less than 15 seconds after blood flow to the brain has stopped, and irreparable damage to the brain tissue occurs in about 5 minutes.
Blood supply = arterial supply + venous drainage
ARTERIAL SUPPLY
Anterior circulation
Posterior circulation
Major vessels : Internal carotid ; Vertebral arteries
CIRCLE OF WILLIS
The circle of Willis (after the English neuroanatomist Sir Thomas Willis
Formed by
Vertebro-basilar system branches
Internal carotid and its branches
VERTEBRO BASILAR SYSTEMVERTEBRAL ARTERIES
Origin: Subclavian Arteries
Course: ascend through the transverse foramen of the upper six cervical vertebra.
Intracranial Entry via foramen of Magnum
VERTEBROBASILAR SYSTEM
BRANCHES
1. Anterior spinal artery
2. Posterior Inferior Cerebellar Artery (PICA)
3. Basilar Artery
oAnterior Inferior Cerebellar Artery (AICA)
oPontine arteries
oSuperior Cerebellar Artery
oPosterior Cerebral Artery
PICA
the largest branch of the vertebral artery arises at the caudal end of the medulla on each side
Runs a course winding between the medulla and cerebellum
It supplies
a. posterior part of cerebellar hemisphere
b. inferior vermis
c. central nuclei of cerebellum
d. choroid plexus of 4th ventricle
e. medullary branches to dorsolateral medulla
AICA
It arises from the basilar artery at the level of the junction between the medulla oblongata and the pons in the brainstem.
It passes backward to be distributed to the anterior part of the undersurface of the cerebellum, anastomosing with the posterior inferior cerebellar branch of the vertebral artery.
It supplies
a. the anterior inferior quarter of the cerebellum.
b. the middle cerebellar peduncle,
c. facial (CN VII) and vestibulocochlear nerves (CN VIII)
SUPERIOR CEREBELLAR ARTERY Branch of from lateral aspect of basilar artery
It supplies
a. most of the cerebellar cortex,
b. the cerebellar nuclei, and
c. The superior cerebellar peduncles
POSTERIOR CEREBRAL ARTERY P1 – pre communicating segment
Posterior thalamoperforating
Medial posterior choroidal
P2- ambient segments
Lateral posterior Choroidal
Thalamogeniculate arteries
Cortical branches
POSTERIOR CEREBRAL ARTERY
1. Central branches
Thalamoperforating & thalamogeniculate
supply the medial surfaces of the thalami and the walls of the third ventricle
Peduncular perforating branches
supply a considerable portion of the thalamus.
POSTERIOR CEREBRAL ARTERY2. Choroidal branches
Medial posterior choroidal branches
supply the tela chorioidea of the third ventricle and the choroid plexus
Lateral posterior choroidal branches
small branches to the cerebral peduncle, fornix, thalamus, and the caudate nucleus
POSTERIOR CEREBRAL ARTERY
3. Cortical branches
Anterior temporal & Posterior temporal
Lateral occipital
Medial occipital
Splenial or the posterior pericallosal branch
Supplies infero-medial part of the temporal lobe,
occipital pole, visual cortex, and
splenium of the corpus callosum
ANTERIOR CIRCULATION
Middle Cerbral artery
Anterior Cerebral artery
MIDDLE CEREBRAL ARTERY arises from the Internal Carotid
continues to lateral sulcus and divides into different branches
Course is divided into segments M1, M2 , M3 , M4
M1 from orgin to trifurcation
M2 from bifurcation to origin of cortical branches
M3 opercular branches (within sylvian fissure)
M4 emerges from sylvian fissure into surface of the hemisphere
MCA (BRANCHES)
M1-
•medial lenticulostriate penetrating arteries
•lateral lenticulostriate penetrating arteries (Charcot’s Artery)
•anterior temporal artery
•polar temporal artery
•uncal artery
MCA (BRANCHES) M2
Superior and inferior and some times to middle branch
Superior terminal branch
•lateral frontobasal (orbito-frontal) artery
•prefrontal sulcal artery
•pre-Rolandic (precentral) and Rolandic (central) sulcal arteries
Inferior terminal branch
•three temporal branches (anterior, middle, posterior)
•branch to the angular gyrus
•two parietal branches (anterior, posterior)
MCA(BRANCHES)
M3 – opercular branches
M4 - lateral branches to the surface
ANTERIOR CEREBRAL ARTERY
forms at the termination of the internal carotid artery
arches antro-medially to pass anterior to genu of the corpus callosum
It supplies medial aspect of the cerebral hemispheres back to the parietal lobe.
segments
•A1 - origin from the ICA to the anterior communicating artery (ACOM)
•A2 - from ACOM to the origin of the callosomarginal artery
•A3 - distal to the origin of the callosomarginal artery
ANTERIOR CEREBRAL ARTERY
A1- medial Lenticulo striater
A2 – Recurrent artery of Huebner. #
orbitofrontal artey
pericalossal artery
A3 – Terminal Cortical branches
Orbital branches
Supplies
oolfactory cortex
ogyrus rectus
omedial orbital gyrus
Frontal branches supply:
oCorpus callosum *
ocingulate gyrus
omedial frontal gyrus
oparacentral lobule
Parietal branches supply :
oprecuneus
INTERNAL CAPSULE BLOOD SUPPLY
INTERNAL CAROTID Ant. Choroidal artery
Supply lower part of posterior limb & retro-lentiform part
inferolateral part of the lateral geniculate body.
ACA Medial striate branch (Heubner’s)
the lower part of the anterior limb and genu of the internal capsule
MCA Lateral striate (lenticulostriate)
Supplies to the anterior
limb, genu, and posterior limb of the internal capsule
WATERSHED ZONES Area where the blood supply of cortical vessels overlap. These overlapping vessels are Terminal branches
Watershed Infarct:
An area of necrosis in the brain caused by an insufficiency of blood where the distributions of cerebral arteries overlap
WATER SHED INFARCTS
TERITORIAL SUPPLY (CROSS
SECTIONS)
ACA TERITORIES
MCA TERITORIES
PCA TERITORIES
Superior frontal gyrus
Middle frontal gyrus
Postcentral gyrus
Occipital lobe
Lateral ventricles
Corona radiata
Occipital lobe
Lateral horn
ThalamusInternal Capsule
Superior sagittal sinus
VENOUS DRAINAGE
EXTERNAL Veins
Superior Cerbral vein
Superficial & Deep middle Cerebral veins
INTERNAL
Thalamostriate veins
Choroidal veins
OTHERS
Veins draining from midbrain, pons, medulla, cerebellum
DURAL VENOUS SINUSES
EXTERNAL CEREBRAL VEINS
INTERNAL CEREBRAL VEINS
DURAL VENOUS SINUSES
DURAL VENOUS SINUSES
Structure:
The walls of the dural venous sinuses are composed of dura mater lined with endothelium
Name Drains to
Inferior sagittal sinus
Straight sinus
Superior sagittal sinus
Typically becomes right transverse sinus or confluence of sinuses
Straight sinusTypically becomes left transverse sinus or confluence of sinuses
Occipital sinus Confluence of sinuses
Confluence of sinuses
Right and Left transverse sinuses
Sphenoparietal sinuses Cavernous sinuses
Cavernous sinuses
Superior and inferior petrosal sinuses
Superior petrosal sinus
Transverse sinuses
Transverse sinuses
Sigmoid sinus
Inferior petrosal sinus
Internal jugular vein
Sigmoid sinuses Internal jugular vein
CAVERNOUS SINUS
Lateral to body of sphenoid bone
Lateral to body of sphenoid bone
Connected to opposite – intercavernous S
Receives blood
Middle cerebral V
Drains into
Int Jugular V –via Inf petrosal sinus
Transverse S – via Sup petrosal S
Dural Venous sinuses – emissary veins – extracranial V
THANK YOU Dr. Arif khan S
REFERENCE
Netter’s anatomy Atlas
Osborn
MRI Anatomy of Brain
Pubmed
webMD
Radiograpics.rsna.org