ABSTRACT
This chapter discusses the approaches used and lessons learned from intravital microscopy studies of each of the organs. The anatomical components of the immune system play host to many key events in the lives of immune cells, including their generation, maturation, activation, and elimination. The major sites for these events are the bone marrow, thymus, lymph nodes, peripheral lymphatics, and spleen. The hematopoietic stem cell niche is the name given to the complex multicellular and molecular microenvironment within the bone marrow that enables haematopoietic stem/precursor cells to perform their functions of progenitor cell generation and self-renewal. Neutrophils and monocytes play essential roles in the innate immune system. Platelets are the most abundant cell in the circulation, being generated in large numbers on a daily basis. Bone marrow-resident megakaryocytes are responsible for platelet generation, although prior to the application of imaging it was unclear how platelets derived from this large cell located in the bone marrow stroma were delivered into the bloodstream.
