has part has part has_part characteristic of has modifier abnormal hippocampal fimbria morphology absent hippocampal fimbria MPheno.ontology absence of the flattened band of efferent fibers arising from the subiculum and medial border of the hippocampus, which eventually thickens to form the fornix and fibers of the hippocampal commissure MP:0009324 abnormal absent hippocampus fimbria