The middle cerebral artery is a terminal branch of the Arteria carotis interna, one of the three major vessels supplying the brain arterially.
Anatomy
The middle cerebral artery is divided microsurgically into four segments[^1]:
Segment | Course | Arterial branches |
Sphenoidal segment (M1) | The M1 segment courses laterally from the origin of the MCA to the genu, where the MCA forms a 90° loop. The M1 segment is divided into a pre-bifurcation segment and a post-bifurcation segment. In 86 % of cerebral hemispheres, the bifurcation is proximal to the genu of the MCA. | Origin of small cortical arterial branches: "Early branches" |
Insular segment (M2) | The M2 segment of the MCA courses from the genu to the Sulcus circularis insulae. | Multiple branches, particularly at the anterior part of the Insula. |
Opercular segment (M3) | The M3 segment of the MCA courses from the circular sulcus of the insula to the surface of the Sylvian fissure. | Multiple branches. |
Cortical segment (M4) | The branches of the M4 segment of the MCA course from the surface of the Sylvian fissure and distribute over the cortex of the hemispheres. | Multiple branches. |
