Which cells are primarily involved in the second line of defense in the immune system?

The second line of defense in the immune system primarily involves innate immune responses that are non-specific and act quickly to eliminate pathogens after the first line of defense (physical barriers such as skin and mucous membranes) has been breached. Neutrophils and macrophages are key players in this line of defense.

Neutrophils are the first responders to sites of infection or inflammation and are highly effective at engulfing and destroying pathogens through a process known as phagocytosis. They can also release enzymes and reactive oxygen species that help to eliminate microorganisms.

Macrophages also play a crucial role in the second line of defense. They not only engulf and destroy pathogens but also help to stimulate the adaptive immune response by presenting antigens to T cells. This bridging of innate and adaptive immunity is essential for the body to mount an effective response against invaders.

The other cell types listed, such as B cells and antibodies, are primarily involved in the adaptive immune response, which is the third line of defense and takes longer to activate. Similarly, Natural Killer cells and T-cells are important for specific immune responses, particularly against infected or cancerous cells. Eosinophils and basophils are involved mainly in parasitic infections and allergic reactions, rather