Final answer:
The sinuses of a lymph node typically contain reticular fibers, macrophages, dendritic cells, and lymph.
Step-by-step explanation:
Within the sinuses of a lymph node, one typically finds an internal structure consisting of reticular fibers with associated fixed macrophages. Additionally, they may contain dendritic cells, macrophages, and the lymph that has entered the node. Lymphoid follicles with germinal centers of B cells and T cells are found within the cortex, but it is within the medullary sinuses where the lymph collects before exiting the lymph node.