|
The anterior cerebral artery (ACA) is one of a pair of arteries on the brain that supplies oxygenated blood to most midline portions of the frontal lobes and superior medial parietal lobes. The two anterior cerebral arteries arise from the internal carotid artery and are part of the circle of Willis. The left and right anterior cerebral arteries are connected by the anterior communicating artery. Anterior cerebral artery syndrome refers to symptoms that follow a stroke occurring in the area normally supplied by one of the arteries. It is characterized by weakness and sensory loss in the lower leg and foot opposite to the lesion and behavioral changes. ==Structure== The anterior cerebral artery is divided into 5 segments. Its smaller branches: the callosal (supracallosal) arteries are considered as the A4 and A5 segments. *A1 originates from the internal carotid artery and extends to the ''anterior communicating artery'' (AComm). The ''anteromedial central'' (medial lenticulostriate) arteries arise from this segment as well as the AComm, which irrigates the caudate nucleus and the anterior limb of the internal capsule *A2 extends from the AComm to the bifurcation forming the ''pericallosal'' and ''callosomarginal arteries''. The ''recurrent artery of Heubner'' (distal medial striate artery), which irrigates the internal capsule, usually arises at the beginning of this segment near the AComm. Two branches arise from this segment: * *''Orbitofrontal artery'' (medial frontal basal): Arises a small distance away from the AComm * *''Frontopolar artery'' (polar frontal): Arises after the ''orbitofrontal'', close to the curvature of A2 over the corpus callosum. It can also originate from the ''callosal marginal''. *A3, also termed the ''pericallosal artery'', is one of the (or the only) main terminal branches of the ACA, which extends posteriorly in the pericallosal sulcus to form the ''internal parietal arteries'' (superior, inferior) and the ''precuneal artery''. This artery may form an anastomosis with the ''posterior cerebral artery''. * *''Callosal marginal artery'': A commonly present terminal branch of the ACA, which bifurcates from the ''pericallosal artery''. This artery in turn branches into the ''medial frontal arteries'' (anterior, intermediate, posterior), and the ''paracentral artery'', with the cingulate branches arising throughout its length. Depending on anatomical variation, the ''callosal marginal artery'' may be none discrete or not be visible. In the latter case, the branches mentioned will originate from the ''pericallosal artery''. In a study of 76 hemispheres, the artery was present in only 60% of the cases. Angiography studies cite that the vessel can be seen 67% 〔 or 50% of the time. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「anterior cerebral artery」の詳細全文を読む スポンサード リンク
|