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Middle cerebral artery

The middle cerebral artery (MCA) is one of the three major paired arteries that supply blood to the brain. The MCA arises from the internal carotid artery (ICA) as the larger of the two main terminal branches (MCA and anterior cerebral artery) and continues into the lateral sulcus where is branches and provides many branches that supply the cerebral cortex.

Segments

The MCA is divided into M1, M2, M3 and M4 segments :

M1 : from the origin to bifurcation / trifurcation
M2 : from bi (tri) furcation to origin of cortical branches
M3 : opercular branches (those within the sylvian fissure)
M4 : branches emerging from the sylvian fissure onto the surface of the hemisphere

Branches

M1

M2

Division of the MCA is variable after the horizontal segment, although most commonly, it divides into two trunks : superior and inferior :

78 % bifurcate into superior and inferior divisions
12 % trifucate into superior, middle and inferior divisions
10 % branch into many smaller branches

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)

Supply

The middle cerebral arteries supply the majority of the lateral surface of the hemisphere apart from the superior portion of the parietal lobe and the inferior portion of the temporal lobe and occipital lobe. In addition, they supply part of the internal capsule and basal ganglia.