has part has part has_part characteristic of part of has modifier abnormal brain vasculature morphology abnormal basilar artery morphology MP:0013186 any structural anomaly of the unpaired artery that is formed by the union of the two vertebral arteries, runs forward within the skull just under the pons, divides into the two posterior cerebral arteries, and supplies the pons, cerebellum, posterior part of the cerebrum, and the inner ear morphology abnormal basilar artery