What are the two main lineages that hematopoietic stem cells can differentiate into to become white blood cells?

Myeloid lineage and lymphoid lineage

What is the main function of macrophages?

To kill pathogens by phagocytosis and clear cellular debris.

Macrophages that live in specific tissues and perform maintenance roles.

I can describe the structure and function of erythrocytes, leukocytes, and platelets.

1
Most immune cells come from hematopoietic stem cells in the bone marrow, which differentiate into either the myeloid or lymphoid lineage.
2
Macrophages are phagocytic cells that ingest pathogens and cellular debris, while granulocytes like neutrophils, eosinophils, and basophils contain granules filled with antimicrobial chemicals.
3
Adaptive immune cells, such as B cells and T cells, derive from the lymphoid lineage and are able to recognize specific features of pathogens.