What does segmentation of the middle cerebral artery mean?

For the convenience of study and clinical application, the middle cerebral artery is divided into four segments, including sphenoid segment, insular segment, insular operculum segment and cortical segment. Different segments send out different blood vessel branches and supply different parts. Therefore, when a lesion occurs at the distal end of the middle cerebral artery, the damage to the brain is relatively small, because it supplies a small area of brain tissue. When a lesion occurs at the proximal end of the middle cerebral artery, such as arterial thrombosis causing arterial occlusion, it is easy to cause serious symptoms, such as large-scale infarction, and even threaten the patient's life. Therefore, after the middle cerebral artery is segmented clinically, the prognosis of the patient and the severity of the disease are judged according to the lesion site of the vessel.