Which cells in the blood are known to fight infection?

Leukocytes, also known as white blood cells, are the primary cells responsible for fighting infection in the body. They play a crucial role in the immune response by identifying and attacking pathogens such as bacteria, viruses, and other foreign invaders. There are several different types of leukocytes, including neutrophils, lymphocytes, monocytes, eosinophils, and basophils, each with specific functions in immune defense.

In contrast, erythrocytes, or red blood cells, are primarily responsible for transporting oxygen from the lungs to the body's tissues and carbon dioxide from the tissues back to the lungs. Plasma cells are a type of white blood cell that produces antibodies but are not the primary cell types involved in directly fighting infections. Thrombocytes, or platelets, are crucial for blood clotting and preventing bleeding, but they do not play a direct role in combating infections. This distinction emphasizes the unique and essential function of leukocytes in maintaining the body's health and defending against infectious agents.