23. The role of leukocytes in the defence mechanism Page created on October 20, 2019. Last updated on January 24, 2022 at 16:06 I don’t know what they want from this topic. Previous page:22. A-B-0 blood groups. The Rh blood typesNext page:25. Generators and conductors of impulses in the heart. Refractory periods Parent page: Physiology 1