Neutrophils and lymphocytes originate from

Neutrophils and lymphocytes are types of white blood cells (leukocytes) that originate in the bone marrow through a process called hematopoiesis. In adults, the bone marrow serves as the primary source of pluripotent hematopoietic stem cells, which give rise to various lineages including myeloid cells (such as neutrophils) and lymphoid cells (lymphocytes) [4]. Specifically, neutrophils develop and mature within the bone marrow before being released into the circulation or stored in a 'bone marrow reserve'. Similarly, all lymphocytes arise from hematopoietic stem cells in the bone marrow [2]. While B cells largely mature within the bone marrow, T cell precursors migrate from the bone marrow to the thymus for maturation [2]. Other organs like the spleen and lymph nodes are secondary lymphoid organs where these cells reside or proliferate after their initial production in the bone marrow [2].

Sources

1. [1] https://www.sciencedirect.com/topics/neuroscience/lymphoid-organ
2. [4] https://pmc.ncbi.nlm.nih.gov/articles/PMC2669132/
3. [2] https://www.sciencedirect.com/topics/immunology-and-microbiology/lymphoid-tissue