vascular supply of brain

vascular supply of brain

1. VASCULAR ANATOMY OF BRAIN DR . J K PATIL Prof . department of Radio-diagnosis, DY Patil medical college, hospital & research institute Kolhapur

2. Circle of Willis Vessels comprising the circle of Willis include: anterior circulation left and right ICA horizontal (A1) segments of the left and right  anterior cerebral arteries (ACA) single  anterior communicating artery (ACOM) posterior circulation left and right  posterior communicating arteries (PCOM)   horizontal (P1) segments of left and right  posterior cerebral arteries (PCA) single  basilar artery  (tip)

3. C1 (cervical)segment C2(petrous) segment C3( lacerum ) segment C4(cavernous)segment C5( clinoid )segment C6(ophthalmic) segment C7 ( communicating) segmen t Internal carotid artery

4. C1 segment: no branches in neck C2 segment: gives rise to vidian artery caraticotympanic artery supplies middle ear C3 segment: no branches C4 cavernous segment: abducens nerve is inferolateral to ICA. has 2 branches Meningohypophyseal trunk- supplies pituitary gland ,tentorium Inferolateral trunk- supplies cranial nerves CS dura

5. C5 segment: no branches C6 segment : gives 2 branches Ophthalmic artery and superior hypophyseal artery( supplies ant pit lobe, infundibular stalk, optic chiasm) C7 segment: gives anterior choroidal artery.

6. Anterior cerebral artery A1 segment:  from origin to  anterior communicating artery  and gives rise to  medial lenticulostriate arteries (inferior parts of the head of the caudate and the anterior limb of the internal capsule) A2 segment:  from  anterior communicating artery  to bifurcation in  pericallosal artery  and  calloso marginal artery A3 segment:  major branches, excluding terminal branches, which supply the medial portions of  frontal lobes , superior medial part of  parietal lobes , anterior part of the  corpus callosum.

7. Middle cerebral artery The MCA is divided into four segments: M1: sphenoidal or horizontal segment originates at the terminal bifurcation of the internal carotid artery courses laterally parallel to the sphenoid ridge terminates at one of two points at the genu adjacent to the  limen insulae at the main bifurcation M2: insular segment originates at the genu/limen insulae or the main bifurcation courses posterosuperiorly in the  insular  cleft terminates at the  circular sulcus  of insula, where it makes a right angle to hairpin turn M3: opercular segment originates at the circular sulcus of the insula courses laterally along the frontoparietal  operculum terminates at the external/superior surface of the  Sylvian fissure M4: cortical segment originates at the external/top surface of the Sylvian fissure courses superiorly on the lateral convexity terminates at their final cortical territory

8. Posterior cerebral artery  Major terminal branches of distal basilar artery P1 SEGMENT : from basilar artery bifurcation to the junction with PCoA . Gives post thalamo -perforating arteries. P2(AMBIENT SEGMENT): extends from p1-pcoa junction runs in the ambient cistern as it sweeps postero -laterally around midbrain. BRANCHES: Anterior and posterior temporal arteries Thalamogeniculate artery Medial and lateral posterior choroidal artery P3 (QUADRIGEMINAL) SEGMENT Begins behind the midbrain and ends where the pca enters the calcarine fissure of occipital lobe P4 (CALCARINE SEGMENT) Terminates within the calcarine segments & it divides into 2 trunks (med & lat ) Gives medial and lateral occipital artery, parieto Occipital artery, calcarine artery and posterior Splenial artery.

9. Basilar artery The  basilar artery  is part of the  posterior cerebral circulation . It arises from the confluence of the left and right  vertebral arteries  at the base of the  pons  as they rise towards the base of the  brain Branches Before terminating at the upper pontine border where it divides into the two  posterior cerebral arteries it provides several paired branches: anterior inferior cerebellar artery (AICA) labyrinthine artery  (variable origin; more commonly a branch of  AICA ) pontine arteries superior cerebellar artery (SCA)

10. Summary

11. VENOUS SYSTEM OF BRAIN It has 2 major components : dural venous sinuses and cerebral veins. DURAL VENOUS SINUSES Superior sagittal sinus Inferior sagittal sinus Straight sinus Sinus confluence( trocular herophili ) Transverse sinuses Sigmoid sinuses Jugular bulb

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