Corpus: Anterior cerebral artery

The anterior cerebral artery, or ACA for short, is a branch of the internal carotid artery that is one of the three main vessels supplying arterial blood to the brain.

The anterior cerebral artery is a terminal branch of the internal carotid artery. The right and left vessels are connected by the anterior communicating artery. The vessel segment before the exit of the anterior communicating artery is known as the A1 segment and is part of the cerebral arterial circle (Willisi circle). The vessel segment behind the exit of the anterior communicating artery is called the A2 segment.

Clinically and anatomically, a distinction is made between a total of 4 segments of the anterior cerebral artery:

• A1: Pars praecommunicans — part of the cerebral arterial circle
• A2: Pars infracallosa — after the exit of the anterior communicating artery
• A3: Pars praecallosa — along the knee joint
• A4: Pars supracallosa — after wrapping around the knee joint

A2 to A4 are also summarized as pars postcommunicans.

The anterior cerebral artery gives off the following vessels in its course:

• A1: Pars praecommunicans:
  • Anteromedial central arteries
    • Proximal medial striate arteries
    • Supraoptic artery
    • Anterior perforating arteries
    • Preoptic arteries
  • Anterior communicating artery
    • Anteromedial central arteries
      • Suprachiasmatic artery
      • Median commissural artery
      • Median callosal artery
• A2 to A4: Pars postcommunicans:
  • Medial frontobasal artery
  • Distal medial striate artery
  • Polar frontal artery
  • Callosomarginal artery
  • Pericallosal artery

The anterior cerebral artery supplies large parts of the brain. The exact supply area varies greatly between individuals. Broadly speaking, the artery supplies the anterior part of the brain and its medial surface around the longitudinal fissure. The supply area includes, for example:

• Frontal lobe (medial and basal surface)
• Parietal lobe (medial parts)
• Corpus callosum (anterior 4/5)
• olfactory bulb and olfactory tract
• Capsula interna (anterior parts)
• Basal ganglia

Occlusion of the anterior cerebral artery leads to an anterior cerebral infarction (ACA infarction).