Corpus: Middle cerebral artery
1. Definition
The middle cerebral artery, or MCA for short, is a branch of the internal carotid artery and is one of the three main vessels supplying arterial blood to the brain.
2. Course
The middle cerebral artery is a terminal branch of the internal carotid artery and is typically the most important vessel for brain blood supply. It runs in the lateral sulcus towards the occipital region.
Clinically and anatomically, the middle cerebral artery is divided into four segments:
- M1: Sphenoidal segment - extends from the origin to the first major branching. The anterolateral central arteries, which supply the basal ganglia, and occasionally the uncal artery, which runs to the uncus, originate from the M1 segment
- M2: Insular segment - extends within the insular region
- M3: Opercular segment - runs along the operculum
- M4: Cortical segment - runs on the cerebral cortex
3. Branches
The branches of the middle cerebral artery are named according to the regions of the brain they supply.
3.1. ...to the frontal lobe:
- Lateral frontobasal artery
- Prefrontal artery
- Artery of the precentral sulcus
- Artery of the central sulcus
3.2. ...to the parietal lobe:
3.3. ...to the temporal lobe:
4. Function
The middle cerebral artery supplies large parts of the brain. The exact supply area can vary greatly between individuals, but typically includes:
- Lateral parts of the frontal lobe
- Lateral parts of the parietal lobe
- Lateral parts of the temporal lobe
- Thalamus
- Posterior parts of the internal capsule
- Basal ganglia
5. Clinic
Occlusions of the middle cerebral artery and its branches can lead to wedge-shaped cerebral infarcts in its supply area, known as territorial infarcts. Clinically, these are referred to as medial infarcts due to their association with the middle cerebral artery. Additionally, the bifurcation of the middle cerebral artery is a common site for intracranial aneurysms.