Final answer:
Swollen lymphocytes with foamy vacuolated cytoplasm in mononucleosis are often associated with changes in monocytes. However, the specific term for these cells (Downey cells) is not provided in the answer choices. The best choice from the given options would be monocytes (option 3).
Step-by-step explanation:
Infectious mononucleosis, often known simply as mononucleosis or "mono," involves the detection of swollen lymphocytes with foamy vacuolated cytoplasm. These lymphocytes are not neutrophils, eosinophils, nor macrophages but are associated with a condition where abnormal monocytes, another type of white blood cell, are often found due to infection with the Epstein-Barr virus (EBV). Monocytes and their derivatives are known to play a role in the body's immune response to infections like mono.
Lymphocytes are a kind of white blood cell with a large nucleus and a small amount of cytoplasm, and they include varieties such as B and T cells, which are crucial for the adaptive immune response. Swollen lymphocytes with foamy vacuolated cytoplasm seen in infectious mononucleosis are called Downey cells, which are atypical lymphocytes. The correct term for this altered appearance is not specifically mentioned in the options given, but they are characterized by significant changes in monocytes and lymphocytes.
Therefore, the final answer to the question would be option 3) Monocytes, even though the specific term for the swollen lymphocytes associated with mononucleosis is not listed among the choices provided in the question.