Final answer:
Lymphocytes are the type of white blood cells found in the outer cortex of a lymph node. They play a crucial role in the immune response.
Step-by-step explanation:
The type of white blood cells found in the outer cortex of a lymph node are lymphocytes. Lymphocytes are a type of white blood cell that play a crucial role in the immune response. They are characterized by a large nucleus and a small rim of cytoplasm. Lymphocytes are found in high concentrations in lymph nodes, where they help filter and destroy harmful substances.