Middle cerebral artery

The middle cerebral artery (MCA) is one of the three major paired arteries that supply blood to the cerebrum. The MCA arises from the internal carotid and continues into the lateral sulcus where it then branches and projects to many parts of the lateral cerebral cortex. It also supplies blood to the anterior temporal lobes and the insular cortices.
The left and right MCAs rise from trifurcations of the internal carotid arteries and thus are connected to the anterior cerebral arteries and the posterior communicating arteries, which connect to the posterior cerebral arteries. The MCAs are not considered a part of the Circle of Willis.
Structure.
The middle cerebral artery can be classified into 4 parts:
The M2 and M3 segments may each split into 2 or 3 main trunks (terminal branches) with an "upper trunk", "lower trunk" and occasionally a "middle trunk". Bifurcations and trifurcations occurs in 50% and 25% of the cases respectively. Other cases include duplication of the MCA at the internal carotid artery (ICA) or an accessory MCA (AccMCA) which arise not from the ICA but as a branch from the anterior cerebral artery. The "middle trunk" that exist in parts of the population, when present provides the "pre-Rolandic", "Rolandic", "anterior parietal", "posterior parietal" and the "angular artery" for irrigation instead of the "upper" and "lower trunks".
The branches (ramus) of the MCA can be described by the areas that they irrigate.
Function.
Areas supplied by the middle cerebral artery include:
MCA occlusion site and resulting Aphasia
Clinical significance.
Occlusion.
Occlusion of the middle cerebral artery results in Middle cerebral artery syndrome, potentially showing the following defects: