The structures of invocation, in medias res, and flashback in epics contribute to the sense of drama and heightened meaning by adding depth and complexity to the narrative. The invocation, which is a prayer or call for inspiration at the beginning of the epic, sets the tone and prepares the audience for the grandeur and significance of the story. In medias res, which means "in the middle of things," plunges the audience into the action right away, creating a sense of immediacy and excitement. Flashbacks, on the other hand, provide background information and reveal important events from the past, enhancing the understanding of the characters and their motivations. These structural techniques help to intensify the dramatic impact and enrich the meaning of the epic.