This research aims to determine the impact of a didactic sequence mediated by a Virtual Learning Object (OVA) on strengthening the understanding of the circulatory system. The study employs the constructivist pedagogical model, implementing the teaching strategy for understanding proposed by Perkins and Blythe. The purpose is to foster comprehension skills through the design of generative topics that lead to understanding goals, facilitating the acquisition of meaningful learning. The methodology is framed within action research with a mixed approach, applied to seventh-grade students at Liceo La Presentación Sogamoso. Additionally, an OVA was developed that meets the characteristics of teaching for understanding, following the ADDIE instructional methodology, divided into three categories: circulation in vertebrates, circulatory system in humans, and diseases. The pretest revealed deficiencies in recognizing the functioning of circulatory system components and associated diseases. Students had difficulties in articulating biological phenomena, such as the functioning of the heart. The OVA, as a mediating tool, facilitated a motivating and dynamic approach to the topic through multimedia elements, improving the understanding of theoretical concepts. Learning situations included in the tool are designed to reflect real-world scenarios, motivating students to relate concepts to solve problems and promoting thinking skills for understanding. Finally, it was evident that when students engage in comprehension processes, they generate meaningful learning. They are capable of articulating, evaluating, and associating new knowledge to effectively address concrete situations.