Arteries of the head: Internal carotid artery (Latin)

The a. carotis interna originates from the a. carotis communis. It is usually divided into seven distinct parts based on its course and anatomical relations. This classification uses a numerical scale (C1-C7) based on the direction of blood flow and describes the segments anatomically based on the compartments through which they travel. The a. carotis interna enters the cranium via the canalis carotidis ossis temporalis. Segments C1, C3 and C5 usually do not have any rami, while small/variable may arise from segments C2 and C4. Segments C6/C7 provide several rami which supply the anterior circulation of the encephalon, as well as the orbita: a. ophthalmica, a. hypophysialis superior, a. communicans posterior, a. chorioidea anterior, a. anterior cerebri, a. media cerebri.