The tenth version of the BioASQ Challenge will be held as an evaluation Lab within CLEF2022. The motivation driving BioASQ is the continuous advancement of approaches and tools to meet the need for efficient and precise access to the ever-increasing biomedical knowledge. In this direction, a series of annual challenges are organized, in the fields of large-scale biomedical semantic indexing and question answering, formulating specific shared-tasks in alignment with the real needs of the biomedical experts. These shared-tasks and their accompanying benchmark datasets provide an unique common testbed for investigating and comparing new approaches developed by distinct teams around the world for identifying and accessing biomedical information. In particular, the BioASQ Challenge consists of shared-tasks in two complementary directions: (a) the automated indexing of large volumes of unlabelled biomedical documents, primarily scientific publications, with biomedical concepts, (b) the automated retrieval of relevant material for biomedical questions and the generation of comprehensible answers. In the first direction on semantic indexing, two shared-tasks are organized for English and Spanish content respectively, the latter considering human-interpretable evidence extraction (NER and concept linking) as well. In the second direction, two shared-tasks are organized as well, one for biomedical question answering and one particularly focusing on the developing issue of COVID-19. As BioASQ rewards the approaches that manage to outperform the state of the art in these shared-tasks, the research frontier is pushed towards ensuring that the valuable biomedical knowledge will be identifiable and accessible by the biomedical experts.