Arteries of brain

arteries supplying brain

1. Blood supply of brain

2. Arteries supplying Brain
•Brain needs continuous arterial
supply
•If there is block for
•More than 5 minutes
•Neurons will die
•Brain uses
•20 % of inspired Oxygen

3. Arteries supplying Brain
•Provided by Two Systems
•Anterior and posterior systems
•Anterior system (circulation)
•Carotid System
•Supply anterior portion of the brain
•Posterior system (circulation)
•Vertebro-Basilar System
•Supply posterior portion of the brain
•Anterior and posterior circulations
are interconnected via
•Posterior communicating arteries

4. Arteries supplying Brain
•From
•Internal carotid artery
•From Common carotid
•Left from arch of aorta
•Right brachiocephalic
•Vertebral artery
•From subclavian
•Arteries supplying brain are lying
•Within subarachnoid space

5. Branching pattern of cerebral arteries
•2 types
•Central & cortical
•Central
•Supply interior of cerebral
hemispheres
•Pierces through anterior or posteior
perforated substance
•End arteries
•Form six groups
•Antero medial
•By anterior cerebral and anterior
communicating
•Posteromedial
•By posterior cerebral & posterior
communicating
•Anterolateral(rt& Lt)
•Middle cerebral
•Posterolateral(rt& lt)
•Postriorcerebral

6. Branching pattern of cerebral arteries
•Cortical branches
•They form anastomosis
•But they become end arteries after enters
the substance
•2 groups
•Long cortical
•Also known as medullary
•They pass through cortex to white
matter
•Short cortical
•Restricted to cortex
•Form network in middle zone of cotes
•Outer & inner zones are least arterial
supply

7. Vertebral artery
•From
•First part of subclavian
•Has 4 parts
•1
st
part
•Before entering
•2
nd
part
•Through first 6 foramen
transversarium
•3
rd
part
•In suboccipitalregion
•4
th
part
•Passes through foramen magnum
•Within cranial cavity

8. Vertebral artery –cranial cavity
•IV part Enters cranial cavity
•Through foramenmagnum
•Pierces dura & arachnoid matter
•Lies in subarachnoid space
•Passes medially anterior to medulla
•Till inferior border of pons
•Where 2 vertebral arteries join
•To form basilar artery

9. Vertebral artery cranial part -Branches
•Anterior spinal artery
•Posterior spinal
•Posterior inferior cerebellar
•(Largest branch)
•Meningeal arteries
•Supplies the dura matter of posterior
cranial fossa
•Medullary arteries
•Supplies medulla oblongata

10. Anterior spinal artery
•Formed by the union of
branches from bothvertebral
arteries
•Descend in front of the
medulla to reach and supply
the spinal cord
•Runs caudally
•In anterior medianfissure
•Ends at filumterminale
•Supplies
•Anterior two third of cord
•Enhanced by segmental
arteries

11. Posterior spinal artery
•Either from
•Vertebral or Posterior inferior cerebellar
arteries
•Runs down in posterolateral sulcus
•Supplies
•Posterior one third of thecord

12. Posterior inferior cerebellar artery
•Supplies
•Medulla
•Inferior part of cerebellum
•Choroidal branch to fourth
ventricle
•Sometimes posterior spinal branch

13. Basilar artery
•2 vertebral arteries unite
•At the junction between medulla and
pons
•Form basilar artery
•Runs the length of the pons and supplies it
by pontine branches.
•At the junction of pons and midbrain
•Divides into
•2 Posterior cerebral arteries

14. Basilar artery -
branches
•Superior cerebellar artery
•Pontine branches
•Labyrinthine artery
•Pass through the internal acoustic
meatus -inner ear
•Anterior inferior cerebellar
artery
•Posterior cerebral arteries
•At upper pons

15. Posterior cerebral artery
•Terminal branches of basilar artery
•Curves laterally
•Around cerebral peduncle
•Passes back
•To tentorial surface of cerebrum
•Separated from
•Superior cerebellar artery by
•Oculomotor nerve
•Connected with ICA by
•Posterior communicating artery

16. Posterior cerebral artery -branches
•Branches can be divided into
•Cortical & central
•Cortical branches
•Supply visual area
•Inferior surface
•Occipital lobe
•Temporal lobe except temporal pole
•Superolateralsurface
•Inferior temporal gyrus
•Occipital lobe
•Medial surface
•Lingual gyrus
•Cuneus
•Posterior part of precuneus

17. Applied anatomy
•Occlusion of posterior cerebral artery
•Produces hemianopia (contralateral
side) (partial blindness)

18. Posterior cerebral artery -branches
•Central branches
•Posteromedial group
•Together with branches of posterior
communicating artery
•Pierces posterior perforated substance
•Supplies
•Anterior part of thalamus and globus
pallidus
•Posterior choroidal
•Enters inferior horn of latventricle
•Through choroid fissure
•Supplies
•Choroid plexus & lateral geniculate body

19. Carotid system

20. Internal carotid artery
•From
•Common carotid
•Has 4 parts
•Cervical
•Petrous
•Cavernous
•Cerebral

21. Internal carotid
•Enter middle fossa
•Through carotid canal (petrous part)
•Reach the side of body of sphenoid bone
•Turns forward in cavernous sinus (cavernous part)
•To reach the medial aspect of anterior clinoid process
•Lies lateral to optic chiasma (cerebral part)

22. Internal carotid –cerebral part
•Branches
•Opthalmic
•Anterior cerebral
•Middle cerebral
•Posterior communicating
•Anterior choroidal

23. Anterior choroidal
•Runs backwards
•Just below optic tract
•Supplies
•Crus cerebri
•Lateral geniculate body
•Globus pallidus
•Internal capsule (post limb)
•Caudate nucleus
•Optic radiation
•Enters
•Inferior horn of Lateral ventricle
•Forms choroid plexus

24. Middle cerebral
•Largest terminal branch of ICA
•Begins at ant perforated substance
•Passes in stem of lateral sulcus
•Reaches insula
•Divides into
•Cortical branches
•Supplies
•Inferior surface
•Superolateralsurface

25. •Inferior surface
•Lateral half of orbital surface
•Superolateralsurface
•Entire surface except
•Occipital lobe
•Small strip of
•Superomedialborder
•Tentorial part of inferolateralborder
•Medial surface
•Temporal pole
Middle cerebral artery -Areas supplied by cortical branches

26. Middle cerebral artery -Areas supplied by central branches
•Lateral striate
•Pierces cortex to reach lentiform
•Some branches pierce lentiformand
supplies
•Internal capsule
•Artery of Cerebral haemorrhage
•One of the lateral striate branches is
very large
•Liable to rupture due to high BP

27. Anterior cerebral
•Smaller terminal branch of ICA
•Begins at
•Stem of lateral sulcus
•Passes anteromedially
•To reach posterior part of medial orbital border
•Where communicated with opposite side artery by
•Anterior communicating artery
•Reaches medial surface
•Curves around the genu
•Passes posteriorly on body of corpus callosum
•Turns upwards infrontof parietooccipital sulcus

28. Anterior cerebral -Areas supplied by cortical branches
•Cortical branches
•Inferior surface
•Medial half of orbital surface
•Medial surface
•Uptoparieto-occipital sulcus
•Corpus callosum, cingulate
gyrus, paracentral lobule &
precuneus
•Superolateralsurface
•Strip of cortex along
superomedialborder upto
parieto-occipital sulcus
•Upper part of motor &
sensory areas (lumbosacral
region)

29. Anterior cerebral artery –central branches
•Piercing anterior perforated substance
•Supplies
•Head of caudate nucleus
•Lentiformnucleus (anterior part)
•Rostrum of corpus callosum

30. Circle of Willis
•An arterial circle situated at
the interpeduncular cistern
•At base of brain
•Encloses
•Optic chiasma and structures
in interpeduncular fossa
•Joins Carotid &
Vertebrobasilarsystems

31. Circle of Willis
•Extent
•From upper border of Pons
•To medial longitudinal fissure
•Shape
•Polygonal than circular

32. Circle of Willis
•Formation
•Front
•2 anterior cerebral arteries
•Joined by anterior communicating artery
•Posterior
•Basilar artery divides into
•Posterior cerebral arteries
•On sides
•Posterior communicating
•Connecting ICA with PCA

33. Circle of Willis -Branches
•Provide central branches
•End arteries
•Pierce the brain and supplies deep part
•Arranged in groups
•They are
•Anteromedial group
•Anterolateral group
•Posterolateral group
•Posteromedial group

34. Circle of Willis -branches
•Anteromedial group
•Branches from
•Anterior cerebral
•Anterior communicating
•Piercing anterior perforated
substance
•Supplies
•Preoptic, supraoptic& anterior
parts of hypothalamus

35. Circle of Willis -branches
•Anterolateral group
•From
•Middle cerebral artery
•Pierce
•Anterior perforated substance
•Supplies
•Corpus striatum & internal capsule

36. Circle of Willis -branches
•Posterolateral group
•From
•Posterior cerebral artery
•Supplies
•Posterior part of thalamus
•Geniculate bodies
•Posteromedial group
•From
•Posterior cerebral & posterior communicating
•Supplies
•Anterior part of thalamus
•Lateral wall of III ventricle

37. Arterial Disorders
•Stroke
•Blood supply to the brain is
interrupted or reduced
•Either by
•Ischemia
•Hemorrhage
•Aneurysm
•Dilation of the wall (may take
years)

38. •A weak or thin spot on an
artery in the brain bulges
•Aneurysm can put pressure
on the nerves or brain tissue
•Burst or rupture
•Leads to hemorrhage